SURGICAL OUTCOMES FOLLOWING POSTERIOR CAPSULE RUPTURE DURING PHACOEMULSIFICATION SURGERY

Dissertation submitted for MS (Branch III) Ophthalmology April 2014

The Tamil Nadu Dr. M.G.R Medical University Chennai - 600032

CERTIFICATE

Certified that this dissertation titled “Surgical outcomes following posterior capsule rupture during phacoemulsification” submitted for Master of Surgery

(Branch III) Ophthalmology, is a bonafide work done by Dr. Shilpa Das under our supervision and guidance in the department of Cataract and IOL Services at

Aravind Eye Hospital and Postgraduate Institute of Ophthalmology, Madurai, during her residency period from May, 2011 to April, 2014.

Dr.Haripriya Aravind Dr.M.Srinivasan

Head of department DirectorEmeritus Cataract and IOL services Aravind Eye Hospital Aravind Eye Hospital Madurai Madurai

ACKNOWLEDGEMENT

I would like to pay my respects to Dr.G.Venkataswamy, the founder of Aravind

Eye Care System who was a great humanitarian and a source of inspiration for thousands of people across the globe. I thank Dr. Haripriya Aravind, Head of department of Cataract and IOL services for giving me the opportunity to do this study and for her guidance through my study. I sincerely thank Dr.N.Venkatesh

Prajna, Chief of Medical Education for his support throughout my residency. I pay my gratitude to Dr.P.Namperumalsamy, Chairman Emeritus;

Dr.G.Natchiar, Director of Human Resources; Dr. M.Srinivasan, Director

Emeritus and Dr.R.D.Ravindran, Chairman whose untiring efforts have contributed in a major way to reduce blindness in our country.

I thank Dr. Madhusekhar, Dr. Dhanya and Dr. Sonali for their valuable suggestions. I thank biostatician Mr.Vijayakumar for helping me with data analysis for my study. I am indebted to librarian Mrs. Kumaragurupari for all the valuable data she provided me for my study. I am grateful to the patients involved, without which the study would not have been possible.

Above all I thank my family for their love, constant support and encouragement that brings me to what I am today.

INDEX

PART I

Introduction 1

Anatomy of posterior capsule 3

Posterior capsule rupture 6

Phacoemulsification 9

Phacoemulsification and posterior capsule rupture 21

Post operative complications 37

Review of literature 48

PART II

Aims and objectives 56

Materials and methods 57

Results 61

Discussion 82

Conclusion 90

INTRODUCTION

Cataract is the leading cause of preventable blindness in the world. Reduction of the burden of cataract blindness from senile cataracts is essential economically and socially to provide dependence free life style to the aged population.

Cataract surgery is one of the most frequently performed surgeries today.

Contemporary cataract extraction has good success in terms of visual acuity and visual function improvement. However any surgery has potential risks and complications that may affect the post operative outcome. The modern day cataract surgery is designed to lessen potential complications, provide adequate comfort, speed up post operative recovery and provide a good visual outcome to patients. Many techniques have been devised to prevent and manage complications so as to achieve this goal.

Surgery for cataract has evolved from the ancient technique of couching during fifth century BC to the recent phakonit and femtosecond phaco surgeries. Today phacoemulsification is the favored procedure for cataract extraction. Hence the necessity of knowledge regarding prevention and management of complications associated with this surgery cannot be over emphasized. During surgery unintended trauma may occur to various structures like the cornea, iris, zonules,

lens capsule etc. Among these, a rupture of the posterior capsule is one of the most dreaded complications since it can lead to a series of other events finally resulting in a poor visual outcome for the patient.

This study is designed to determine the dynamics around occurrence of posterior capsule rupture during phacoemulsification, assess its management and analyze its influence on the visual outcome of patients.

ANATOMY OF THE POSTERIOR CAPSULE

The lens capsule is a thin, smooth, transparent membrane which completely surrounds the lens. It originates as the basement membrane of the epithelial cells of the embryonic lens vesicle. The posterior vesicle cells elongate anteriorly to fill the vesicle. Thus the capsule assumes an anterior and posterior surface. The anterior part of the lens capsule continues to remain as a basement membrane for the anterior epithelial cells however the posterior part now exists as merely a thin membrane adherent to fiber cells growing along its inner aspect. The capsule varies in thickness from 2-28 micrometers (µm) (John Forrester, 1996).

It is much thicker anteriorly than posteriorly and it is thicker towards the equator than at the poles. The capsule has a lamellar structure with scattered filamentous elements which are responsible for its elasticity (Fisher et al, 1976). These lamellae are parallel to the capsular surface and consist of type IV collagen fibrils which are embedded in a matrix of glycoproteins and sulfated glycosaminoglycans. The capsule can be stretched up to 60% of its circumference without giving away. This elastic property allows such a thin membrane to maintain its integrity. The thinnest part of the lens capsule lies at its posterior pole, measuring only about 2.8-4 µm in thickness (Snells et al,

1998). The tensile strength of the posterior capsule is greater than that of anterior capsule.

Changes in capsular thickness:

While the anterior capsule might thicken as much as two times, the posterior capsule does not thicken with age. In fact with the development of certain types of cataracts the posterior capsule becomes very thin and fragile. These include hard and hypermature cataracts. Pseudo exfoliation is another situation where the capsule becomes very brittle. In case of posterior polar cataracts and eyes that are myopic, the posterior capsule is thin and adherent to the cataract.

Understanding the anatomy of posterior capsule and conditions that may cause changes in its thickness is essential to a cataract surgeon to anticipate the behavior of the posterior capsule during surgery.

THICKNESESS OOFF LELENSNS CCAPSULEAPSULE

ANTERIOR POSTERIOR

POSTERIOR CAPSULE RUPTURE

A breach in the integrity of the posterior capsule can be congenital, traumatic, spontaneous or can occur during surgery. Preexisting congenital tears may be a result of intrauterine insult while traumatic tears may occur as a result of direct mechanical impact due to penetrating or blunt injury. Intrasurgical posterior capsule ruptures are the most common type and may occur accidentally during any step of cataract surgery. Sometimes during surgery, a posterior capsular tear may be planned as in case of a primary posterior continuous curvilinear capsulorrhexis (Vajpayee et al, 2001).

Several factors may contribute to an increased chance of posterior capsule rupture during surgery. The important risk factors are summarized as follows:

Risk Factors for Posterior capsule rupture (Tanuj Dada et al, 2008)

1. Poor visibility

2. Pseudoexfoliation

3. Hard/Morgagnian cataracts

4. Posterior polar cataracts

5. Posterior lenticonus

6. Traumatic cataracts

7. High myopia

8. Eyes with previous vitrectomy

6. Cataracts with persistent primary hyperplastic vitreous

7. Intrasurgical causes (Discussed later)

Poor visibility of the operating field, attributed to the presence of any opacities or scars on the cornea, fleshy pterygiums etc increases the risk of a posterior capsule (PC) rupture by preventing the surgeon to clearly visualize what he is doing.

Eyes with pseudoexfoliation have brittle lens capsules prone for tear, poorly dilating pupils that hamper visibility and harder nuclei which require more energy for emulsification. These factors increase the risk for capsular rupture

(Tanuj Dada et al, 2008).

In case of posterior polar cataracts, the capsules are extremely thin and the cataract itself is very adherent to the posterior capsule making it vulnerable to dehiscence during surgery (Robert H.Osher et al, 1990). Hard cataracts have thin fragile, lax capsules with wrinkles, high chance of running away of anterior capsulorrhexis and minimal epinuclear sheet that usually acts as a cushion

protecting the posterior capsule from direct trauma. Thus very susceptible to posterior capsular trauma. Traumatic cataracts may have an underlying posterior capsule defect that might not have been detected preoperatively or a weak capsule prone to rupture even with trivial instrumentation.

Myopic eyes have a tendency for development of cataract at a younger age.

These cataracts are strongly adhered to the capsules that demand a good hydrodissection in order to minimize trauma to capsule while nuclear manipulation. Also the posterior capsules in these eyes are highly mobile that may impose a greater risk of a posterior capsule rupture. The increased mobility and flaccidity of the PC is also seen in eyes following vitrectomy that predisposes it to a tear during surgery.

PHACOEMULSIFICATION

Phacoemulsification was developed by Charles Kelman in 1967. This technique uses a very small incision compared to the conventional Extracapsular cataract extraction (ECCE) and manual small incision cataract surgery (SICS). In phacoemulsification, an ultrasonic probe is used to fragment and emulsify the nucleus, and an automated aspiration system is used to aspirate the cortex, both of which can be controlled by the surgeon.

Advantages

1. Rapid visual rehabilitation

2. Stable anterior chamber that protects against positive vitreous pressure

3. Lesser wound related complications and faster wound healing

The phacomachine has several parts and attachments:

Console

The console comprises of a computer which controls all the machine functions and settings for various parameters. These settings represent the maximum level of the parameter that can be reached. Settings for different surgeons and

different cataract types can be installed into the memory of new generation machines.

Handpiece

Two types of handpieces are used during phacoemulsification surgery:

1. Phaco or ultrasonic handpiece

2. Irrigation aspiration handpiece

The phaco handpiece contains an acoustic vibrator or piezoelectric crystal, which stays in contact with the tip. The acoustic vibrator has a longitudinal oscillation oscillates of frequency between 30,000-60,000Hz providing a linear motion to the tip. The phaco energy hence forth transmitted to the tip which is covered by a silicon sleeve. The tip is costituted of titanium. It can have different bevel angles ranging from 0-60, most common being 30 and 45 angle tips. The tip is cooled by an infusion fluid that flows between the tip and the sleeve. Perpendicular to the tip bevel, there are two openings on the sleeve for the exit of fluid.

Irrigation aspiration hand piece is smooth and round with single aspiration port on its side. It is also covered by a silicon sleeve through which irrigation occurs. The irrigation ports in the silicone sleeve are aligned perpendicularly to

the metallic aspiration port. These tips may be straight or angulated at 45 or 90 degrees. The lumen diameter can be variable like 0.2, 0.3 and 0.7mm. The

0.3mm tip is most frequently used.

Foot Pedal

Foot pedal comprises of a main central part and side kicks. It controls three main functions i.e infusion, aspiration and phaco power. The entire distance traversed by the foot pedal is subdivided into three excursions:

I (irrigation only)

IA (infusion and aspiration)

IAP (infusion, aspiration and phacopower)

Resistance is felt at the position where the mode changes. Being familiar with tactile feedback and auditory feedback of the machine is essential for phacoemulsification.

The main functions of phacomachine include ultrasonic fragmentation, irrigation and aspiration.

Phaco parameters:

1. Ultrasound power: Phaco power is generated by the ultrasonic vibrations of the Quartz crystal present in the hand piece. There may be 2–6 crystals. The frequency has a range from 29–60 Hz in different machines. In each machine, the frequency remains fixed and the power can be varied.

2. Stroke length is the to and fro movement of the tip and varies from 2/1000–

6/1000 of an inch. The movement of the tip is usually forwards and backwards.

The tip can move transversely or elliptically in the newer fourth generation machines, which increases the followability, heat generation and hold of the tip against the lens matter.

3. Irrigation system: It consists of a bottle, the height of which provides the gradient for flow. A pinch valve which is controlled by the foot pedal, regulates the bottle tubing. The infusion is dependent on gravity, a 2 feet bottle height conforming to about 44 mmHg. A bottle height of 3 ± 1 ft maintains appropriate

IOP for performing surgery safely.

4. Aspiration system: Functions of the aspiration system include lavage of the anterior chamber and creation of a hold of the lens, for emulsification/crushing of the. Hold is a function of the vacuum generated by the machine and lavage is

controlled by the flow rate and. The aspiration systems consist of a pump that may of different types: a) Venturi Pump: In a venturi pump, vacuum is created in a closed chamber.

This vacuum is transmitted to the handpiece. The rapid movement of a compressed gas creates a negative suction force, i.e. the vacuum, inside a closed chamber. The level of vacuum developed is decided by the amount and speed of the gas . The foot pedal controls this process. Vacuum build up is almost instantaneous from zero to the maximum preset value and does not depend on occlusion of aspiration port by lens matter. With rapid rise in vacuum, there is increase chance of a posterior capsule rupture or trauma to other anterior segment structures, especially in the hands of beginners who have poor expertise. In this system only the level of vacuum can be controlled but not the flow rate, which is the rate at which fluid is drawn from the anterior chamber.

The flow rate is a fixed fraction of the vacuum. However, change in vacuum level doesn’t proportionately change the flow rate. The size of the ports and resistance encountered in the passage also modify flow rate. The advantage of this system is that the vacuum is directly transmitted to the tip from the system ensuring a better followability. Followability the ease with which lens fragments are drawn towards the tip.

b) Peristaltic Pump: In a peristaltic pump, the rotation of the rollers by the pump squeeezes the soft, silicon tubing, creating a negative pressure by drawing the fluid out of the tube. Fluid is withdrawn based on the speed with which the rollers rotate, thus determining the flow rate. In this system, vacuum is built up only after the occlusion of the tip by the lens. Flow rate and vacuum can be set independently in a peristaltic system. Hence the system is safe for surgeons who are beginners. c) Diaphragmatic (constant) pump: The diaphragmatic pump uses a flexible membrane within a cassette to build up vacuum. The buildup of vacuum is linear unlike the other two pumps, and reaches preset level without occlusion of the tip. This mechanism makes it relatively unsafe for aspiration of lens matter.

5. Aspiration flow Rate (AFR): Aspiration flow rate is the rate at which fluid moves out of the eye. Most peristaltic machines work well at an optimum AFR of 20–36 cc/min. The higher the AFR, the faster the debris in the anterior chamber is cleared.

6. Vacuum: Vacuum is a measure of the ‘hold’or grip that the handpiece has on the nuclear fragments. The level of vacuum and size of the ports will determine how good the grip is. The holding power has an inverse relationship with the port size. Vacuum must be used with care depending on what requires to be held

(nucleus/cortex), instrument (phaco tip/ I-A tip) used and the purpose it serves(chopping/ aspiration). Vacuum can be set to a maximum of 120 mmHg,

250 mmHg and 650 mmHg in the first generation, second-generation and third generation machines respectively.

Surge

Surge is defined as the sudden withdrawal of fluid from the anterior chamber after occlusion breaks. The break of occlusion occurs at the end of aspiration of lens matter by the phaco tip. Beyond a certain amount it may cause collapse of chamber, becoming a threat to the vital ocular structures. To maintain constant volume and pressure in the anterior chamber, inflow, i.e. infusion has to be equal to outflow, which is total of aspiration done by the pump and leakage from the site of incision (wound). For a particular bottle height, infusion is constant and leakage are constant. The variable parameters are the aspiration flow rate and the vacuum.

Relationship between vacuum, surge and flow rate: Surge can be reduced by decreasing either the AFR or the vacuum. Decreasing the AFR has linear relation with surge however this makes the events in the anterior chamber slower. Reducing the vacuum decreases the holding capacity. This is not favourable in certain steps like chopping/phacoemulsification of advanced hard

cataract. Hence it is better to lower the AFR in order to decrease surge, while maintaining high vacuum being maintained at the same time. In steps like divide and conquer technique, soft cataracts or epinuclear plate removal, where not much of holding power is necessary, lower vacuum settings can be used to decrease the surge while continuing to maintain the AFR.

Post occlusion surge is one of the important events occurring intraoperatively that increases the chance of a PC rupture. Surgeons have to be very careful to avoid surge especially during removal of last nuclear fragment. With newer machines, presence of in built mechanism and tubing helps prevent surge.

STEPS OF PHACOEMULSIFICATION SURGERY: a) Incision:

The incision could be clear corneal or limbal. Temporal approach is suited for a clear corneal incisionS. The incisions could be uniplanar, biplanar or triplanar.

The size of the incision depends on the keratome used ranging from 2.8 to 3.2 mm b) Continuous Curvilinear Capsulorrhexis (CCC):

A 26 guage bent needle is used to initiate a tear in the central anterior lens capsule. The flap is lifted and turned round the central axis circularly and

completed to join the starting point thus creating continuous edge. The CCC acts like a elastic band resistant to stretching forces. Also radial tears to the periphery can be avoided. c) Hydroprocedures:

Balanced salt solution is used as cleaving force. In hydrodissection, infusion is injected between anterior lens capsule and cortex. The fluid wave spreads around bag and separates the lens from the underlying capsule. This facilitates nucleus rotation and manipulation. In hydrodelineation the fluid is passed, between the epinucleus and nucleus. Posterior epinucleus acts as soft cushion to safeguard the posterior capsule. This technique is followed in cases of posterior polar cataracts where in the cataract is adherent to a thin capsule posteriorly and a forceful hydrodissection may cause dehiscence of the posterior capsule. d) Nucleotomy: The most popular methods of nucleotomy are as follows:

Divide and conquer: Two deep groves or trenches are made at right angles to one another, about 80% depth. The nucleus is divided into four segments by using a second instrument or two instruments and each segment is then emulsified separately.

Stop and chop: This involves trenching, splitting, chopping and phacoemulsification.

The initial trench is made at low vacuum and power based on nucleus hardness.

Trenching is done up to 80% depth. Two instruments, phaco probe and chopper/sinskey hook or two choppers are held deep into trench and force is applied in opposite directions to crack nucleus into 2 hemispheres. Each hemisphere divided into three pieces using chopper and then the smaller pieces are emulsified with phaco probe. The types of chop include horizontal and vertical chop.

Direct Chop: No trench is made, the probe is buried into center of nucleus directly and fragments are generated by chopping. The fragments are simultaneously emulsified and aspirated.

E) Cortex removal:

For removal of cortex, parameters are changed to Irrigation-Aspiration (I-A) mode in the machine. The I-A tip is smaller and high flow settings can be safely used. The tip is positioned below the anterior capsulorrhexis margin and inserted into the cortical fibres. Once they are firmly grasped, they are pulled to center and aspirated.

NuNuclcleotomy and cortrtexex aspiratation f) IOL implantation:

A foldoldable postteerrioior cchahambbeer IOIOLL is injectteed ininto baagg using an injector systeystem, through the small incision. Thhee IOLIOL ununfoldsoldsds andnd iiss tthehheen didiaalled ininntttoo ppoosiititiioon using a dialing hook. g) Closing the wound:

Viscoelastic tthahatt wasas uusesed during surgery is removed first. The chamber is inflated with iirrriggaattiinngg fluluiid. Incision integrity is checked by depdepresressising the posterior lip of the incision. Hydration of strstrooma at the extretreme end of inincisiionon

can be done if the wound is leaking. Corneal edema that occurs on stromal hydration, pulls the tissue against each other and helps in a leak proof closure of the wound.

PHACOEMULSIFICATION AND POSTERIOR CAPSULE

RUPTURE

A posterior capsular rupture can occur at any point of phacoemulsification surgery. Intrasurgically there are several factors that can predispose to capsular damage. They are as follows: (Tanuj Dada et al, 2008)

1. Poor quality of illumination/poor focus of the operating microscope or

excessive pooling of fluid hampering view

2. Surgeon’s level of skill

3. Shallowing of anterior chamber

4. Linear capsulotomy technique (Assia et al, 1991)

5. Peripheral extension of anterior capsulorrhexis

6. Forceful hydroprocedures

7. Excessive nucleus manipulation

8. Trauma directly with phaco tip

9. Rent during cracking soft cataracts

10. Rupture during epinucleus removal or last piece emulsification

11. Tear with a second instrument used for chopping

12. Catching of posterior capsule in irrigation/aspiration tip

13. Damage to posterior capsule from IOL or other instruments like sinskey

hook, keratome etc

PREVENTION:

Recognizing presence of risk factors for a posterior capsular tear during surgery is essential for the surgeon so as to anticipate a complication and modify his techniques based on the situation.

Type of cataract:

Large and hard cataracts need careful hydrodissection since a vigorous technique will cause excess fluid to accumulate around the lens pushing the nucleus forward against the anterior capsular rim creating a capsular block syndrome with a rupture of the posterior capsule (Miyake et al, 1998).

Additional hydrodissection after initial nucleus debulking loosens the remnant peripheral shell from the capsule and allows free rotation and easy emulsification. In hyper mature morgagnian cataracts, after an initial puncture of the anterior lens capsule, liquefied cortex escapes and the bag collapses bringing the posterior and anterior capsules closer to each other. Thus viscoelastic agent can be injected through the initial opening so as to fill up the bag before proceeding with capsulorrhexis. For posterior polar cataracts or cataracts associated with posterior lenticonus, hydrodelineation is preferred over

hydrodissection since the latter can rupture an already thinned out capsule or widen a pre existing defect. Even if hydrodissection is done, it should be partial and fluidic parameters should be reduced. Soft cataracts need careful handling since the posterior capsule may be easily damaged with the phaco tip or a second instrument penetrating through the nucleus.

Myopia

In myopic eyes, where excess fluctuation of the anterior chamber depth predisposes the posterior capsule for rupture, a low inflow as well as low vacuum settings should be used( Tanuj Dada,2008). Similar low settings are useful in eyes that have undergone previous vitrectomy.

Continuous curvilinear capsulorrhexis

A continuous curvilinear capsulorrhexis is a significant factor in the prevention of a posterior capsule tear. The smooth edges act like an elastic band by stretching rather than tearing. If the rhexis is not continuous or intact, even a small tear can run out peripherally and posteriorly disrupting the integrity of the posterior capsule. In the anterior segment, the large central safe zone bound by cornea anteriorly and posterior capsule posteriorly, is the correct area to carry

out surgical maneuvers rather than peripheral shallow zone, in order to maximize capsular safety.

A few phaco techniques have been described that can help decrease the chance of capsular compromise (Roger Steinert, 2010):

1. Slow motion phacoemulsificatio (Osher et al, 2003):

This includes a low aspiration and low vacuum settings which reduces the tendency towards surge

2. Supracapsular phacoflip technique:

Divide and conquer and phaco chop techniques can be used to fragment pieces that can be elevated and emulsified in the supracapsular safe zone

3. Phaco chop:

In this technique, less force is transmitted to the bag than sculpting which uses more of mechanical force rather than ultrasonic energy.

Occurrence of posterior capsule rupture:

Once the PC is compromised, it is essential to recognize this mishap with minimal delay. Several intrasurgical anatomical factors can indicate capsular compromise.

SIGNS OF POSTERIOR CAPSULE RUPTURE: (Tanuj dada, 2008)

1. A sudden deepening of the anterior chamber

2. Pupil SNAP BACK sign

3. Irregular pupillary peeking

4. Posterior movementof the nucleus

5. Decreased mobility of nucleus

6. Difficulty in cortex aspiration

7. Loss of cortical fragmenst posteriorly

8. Tilt or decenteration of IOL

9. Visualization of the torn capsule

10. Flowing of viscoelastic into vitreous cavity

Goals of management:

1. To prevent enlargement of tear

2. To remove nucleus/cortex if left over

3. To minimize vitrectomy and avoid traction

4. To place an IOL and maintain it in a stable position

MANAGEMENT

After a rupture of the posterior capsule has occurred it is very essential to maintain a close stable chamber to avoid rupture of anterior hyaloid face and extension of tear. Depending on when the PC rent has occurred different maneuvers can be followed to subsequently manage the surgery.

NUCLEUS REMOVAL

Converting to Extracapsular Cataract Extraction:

If there is no vitreous prolapse, the nucleus is soft and of limited size a Sheet’s glide can be used and phaco can be continued. As described by Marc Michelson, the glide acts as an artificial posterior capsule to keep lens material from dropping posteriorly. It also shields the phaco tip from aspirating vitreous from below.

However, a large dense nucleus is more safely removed by converting to a large incision manual extracapsular cataract extraction (ECCE). This can be done by abandoning the self-sealing temporal phaco incision, and repositioning for a superior incision. For patients under topical anesthesia, a posterior sub-Tenon's block can be administered with 2 mL of 2% lidocaine before converting to

ECCE . Large superior ECCE incision can be made and the nucleus can sandwiched by viscoelactic agent. An irrigating lens loop/vectis can be used to extract the nucleus. Bimanual pressure counter pressure nuclear expression is contraindicated with a torn posterior capsule.

Lens capsule rupture

ECCE

If most of nucleus is already emulsified with no vitreous disturbance then a second instrument can be used to maneuver rest of nucleus away from tear and complete phacoemulsification. To prevent descend of nuclear fragments into vitreous, the second instrument can be placed below the pieces. A viscoelastic can also be injected to push the fragments anteriorly.

The infusion pressure should not be excessive and at the same time it should be enough to prevent chamber collapse. Also the phaco tip should not be removed

from the anterior chamber without first filling it with viscoelastic in order to maintain the chamber stability

DROPPED NUCLEUS:

After a PC tear has occurred, the following factors may cause drop of partially emulsified nucleus into vitreous:

1. Excessive infusion

2. Vitreous syneresis

3. Repulsion from the phaco ultrasound

4. Forward displacement of anterior vitreous

Viscoat PAL ( Posterior assisted levitation) technique (mentioned in detail later) can be used for nucleus in anterior vitreous. When the nucleus fragment can be brought anteriorly, it can be trapped using a Sheet’s glide, viscoelastic, intracameral miotic or it can be manually removed by a loop or vectis after enlarging the section. (Chang et al, 2003; Michelson et al, 93) Sometimes phacoemulsification in the anterior chamber can also be attempted.

If the nucleus drops down posteriorly to the posterior vitreous or retina, it should not be chased. Section should be closed and three port pars plana vitrectomy and

lensectomy should be done. Chasing the nucleus might cause retinal detachment or tear. IOL can be placed before closing the section depending upon the amount of capsular support left after the rent.

CORTICAL REMOVAL FOLLOWING POSTERIOR CAPSULE

RUPTURE (Chang, 2010: STEINERT)

Bimanual Irrigation-Aspiration (I–A) instrumentation is preferable to a co axial system for epinuclear and cortical extraction. The infusion can be directed away from the aspirating tip because by this manner the irrigation and aspiration currents get dissociated, this avoids pushing loose lens material posteriorly or further hydrating the vitreous. The chamber stability is maintained due to the snug paracentesis and fluid exiting the chamber is less. Thus further vitreous prolapsed can be avoided. Without the constraining silicone irrigating sleeve, the aspirating tip can extend further into the capsular fornices. The quadrants furthest away from residual cortex towards the rent to avoid further extension of tear. Alternately manual dry cortex aspiration can be done using a cannula.

Bimanual irrigation–aspiration handpieces allow dissociation of irrigation and aspiration

currents

VITREOUS LOSS:

When there is vitreous disturbance (loss), to avoid vitreous traction, it is recommended to perform an anterior vitrectomy before extraction of the remaining lens material. Coaxial infusion sleeve should be avoided. A separate self-retaining irrigation cannula should be inserted though a limbal paracentesis that is directed obliquely. This helps in keeping the irrigation circulating within the anterior chamber in such a manner where it cannot expand the capsular defect or hydrate the vitreous. The infusion should not be directed towards the vitreous since this will only prolapsed more vitreous into the anterior chamber

The vitrectomy probe that has a cutting action should be introduced through another paracentesis and vitrectomy carried out. For performing the anterior vitrectomy, a low flow technique is advisable keeping the infusion tip at a higher

level than the cutter. Alternatively dry or no infusion vitrectomy can be performed with repeated viscoelactic injections (Osher, 98)

SPECIAL MANEUVERS:

1. The Visco Trap

Chang proposed a strategy called the Visco Trap which, when combined with a pars plana anterior vitrectomy, can prevent posterior loss of residual lens matter.

(Chang, 2003) The phaco incision is too wide for the sleeveless vitrectomy probe and may result in leakage. This results in poor chamber stability.

Secondly, performing vitrectomy in the anterior chamber will draw more vitreous from the posterior segment forwards. Lastly, as more vitreous exits the eye through either the vitrectomy probe or incision, the residual lens matter that will sink posteriorly. When the posterior capsule is open, it is the vitreous that prevents the remaining lens fragments from descending.

In Visco Trap, the first step is to use a dispersive viscoelastics are used to lift any lens fragments towards cornea. Then the anterior chamber is filled with the dispersive viscoelastic to support and trap the residual lens matter anteriorly and the vitreous is excised from below.

Visco Trap

To effectively trap lens material the viscoelastic should be maximally retentive so that it is less easily let out of the eye by manipulation. In addition, dispersive agents better resist aspiration by the I–A or vitrectomy instruments. Finally, small amounts of retained dispersive viscoelastics are less likely to cause a prolonged or high pressure spike because of their smaller molecular weight.

(Probst, 94)

The vitrectomy cutter is introduced via a pars plana sclerotomy, and is kept behind the capsulorrhexis and papillary plane (Figure below). This breaks down the transpupillary bands, but keeps viscoelastic filled anterior chamber isolated from the vitrectomized posterior chamber. A self–retaining infusion cannula (not shown in figure) is placed through a limbal paracentesis incision.

Vitrectomy cutter

2. Posterior Assisted Levitation technique popularized by Charles kelman:

(Kelman, 96)

This technique is for a partially descended nucleus posteriorly. A Pars plana sclerotomy is made 3.5 mm behind the limbus. Spatula is used to maneuver behind the nucleus before levitating it upwards. Alternatively dispersive viscoelastic can be used behind nucleus

3. Mark Michelson suggested creating create artificial posterior capsule as mentioned earlier, using trimmed sheets glide behind the nucleus over the defect.

4. Conversion to posterior continuous curvilinear capsulorrhexis was popularized by Howard gimbel. Anterior hyaloid face is first retroplaced with visco, a fine forcep is used to grasp and redirect tear to form continuous edge.

This continuous edge is resistant to stretching or tearing forces.

INTRAOCULAR LENS PLACEMENT:

IOL can be placed after a PC rent, only if there is enough residual capsule left for support. If a capsulorrhexis has been made with a single radial tear in the anterior capsule, a single piece acrylic IOL can be placed in the bag. This IOL’s haptics open very slowly and thus they are less likely to extend the tear. Also the lens can be rotated easily. The placement of the lens should be such that the haptics are 90 degrees from the axis of capsulorrhexis tear. Conversion of posterior capsular tear into a rhexis can also permit in the bag implantation of

IOL.

When in the bag placement of IOL is not possible, a three piece IOL especially with C loop haptics may be placed in the sulcus. Single piece IOLs have thicker haptics with unfinished sharper edges and overall shorter length, not suitable for sulcus placement. Capture of the optic in the anterior capsular rim can prevent displacement of the IOL postoperatively. When both the above mentioned is not

possible, other options include anterior chamber IOL, iris fixated IOL, iris claw lens, sclera sutured IOL or glue IOLs.

Recognising remnant vitreous

After necessary maneuvers pilocarpine or acetylcholine may be used to constrict pupil. This not only helps identify any remnant vitreous but also makes it easy to aspirate remnant viscoelastic, which should be done without collapsing the chamber. Sweeping the pupillary area can help ensure there is no prolapsed vitreous left. A peripheral iridectomy prevents vitreous induced pupillary block.

This is advisable in all cases where vitrectomy is not done

Intracameral air can help delineate vitreous strands by interruption of its smooth round contour. Kenalog can also be used to visualize vitreous.

Description of Pars plana vitrectomy technique:

Two conjunctival incisions are made , 3 linear limbus parallel 1.4 mm sclerotomies using microvitreoretinal blades that allow introduction of 20/23/25

G instruments. This is placed in pars plana region, 4mm from limbus in phakics,

3.5 mm in PCIOL and children, 3 mm in aphakics, in mid or anterior pars plana to avoid vireous base which is a 3 mm wide zone of firm vitreoretinal attachment straddling the ora. The infusion cannula is placed in infero temporal

quadrant. Upper two sclerotomies are 140 degress apart to facilitate bimanual manipulation. The sclerotomies accommodate the Infusion, Light source and the

Cutter.Vitreous substitutes can be used to replace volume after vitrectomy especially when dealing with retinal tears or detachment. Air, gases like SF6 and

C3F8 and silicone oil are the various options.

POST OPERATIVE COMPLICATIONS

The following are some of the important complications associated with phacoemulsification complicated with a posterior capsule rupture:

1. Striate keratopathy and corneal epithelial edema

2. Elevated intraocular pressure

3. Cystoid macular edema

4. Retinal detachment

5. Endophthalmitis

6. Chronic uveitis

1. Striate keratopathy and corneal epithelial edema:

Striate keratopathy is edema of the corneal stroma that occurs due to endothelial dysfunction. The endothelium not only acts as barrier but also contains active pump mechanisms that prevent hydration of other layers of the cornea. Any damage to the endothelium compromises these functions. Striate keratopathy manifests as increased corneal thickness, loss of compactness of the stroma and descemet membrane folds. The following factors may contribute to endothelial damage:

a) Mechanical trauma during surgery b) Prolonged surgery c) Inflammation d) Elevated intraocular pressure e) Retained viscoelastic substances/ lens fragments/vitreous in anterior chamber

The risk is higher if there already is a pre existing corneal endothelial dystrophy.

Corneal epithelial edema occurs similarly due to a compromised endothelial function. It may co exist with stromal edema, however if it is present without stromal involvement, then it is solely attributed to an elevated intraocular pressure (IOP). Striate keratopathy and corneal epithelial edema generally occur in the immediate postoperative period and resolve within 4 weeks. Edema lasting for more than three months has a decreased chance of clearing up.

Persistent edema may subsequently lead to bullous keratopathy. Focal corneal edema may occur as a result of retained lens matter or vitreous in the anterior chamber (AC), touching the corneal endothelium

Management:

Striate keratopathy can be treated with hyperosmotic agents like 5% sodium chloride eye drops or ointment. When there is epithelial edema, topical anti

glaucoma medication can be used to lower the intraocular pressure. . A repeat surgery to wash out the remnant lens matter from the AC, an anterior vitrectomy or Nd:YAG vitreolysis to remove vitreous from the anterior chamber can help resolve the corneal edema.

The causes of a reduced visual acuity due to corneal pathology are chronic persistent striate keratopathy, bullous keratopathy, subepithelial scarring and recurrent infectious keratitis secondary to a compromised corneal tissue (BCSC,

AAO 2011).

2. Elevated intraocular pressure:

A transient rise in the intraocular pressure is not uncommon following complicated phacoemulsification surgery. The elevation in the IOP may present in the immediate or late postoperative period depending on the cause. It usually presents as corneal epithelial edema. Elevated IOP may be attributed to:

a. Retained viscoelastic substances

b. Iritis

c. Presence of hypopyon, hyphema or blood clot in AC

d. Endophthalmitis

e. Pre existing glaucoma

f. Excessive use of corticosteroids

g. Retained lens matter or vitreous in AC

h. Pupillary block

i. Presence of peripheral anterior synechiae

Management:

A severe rise in the intraocular pressure in the immediate post operative period may need a release of aqueous from the paracentesis by applying pressure on the posterior lip. Mild to moderate elevation can be controlled with topical and systemic anti glaucoma medication for a short duration. (BSCS, AAO, 2011)

Apart from IOP lowering agents, underlying causes should be treated. Uveitis should be treated appropriately with local and systemic antibiotics and steroids.

Any retained lens matter or vitreous in anterior chamber should be removed as described earlier. Increased use of corticosteroids may manifest as elevated IOP after two to four weeks of surgery. Addition of an IOP lowering agent as well as reducing the steroid dosage can help treat the problem. Pupillary block may occur due to a large air bubble in the posterior chamber, posterior synechiae or positive posterior pressure pushing the IOL forwards. It manifests as iris bombe and a shallow anterior chamnber. Adequate mydriasis using a long acting

mydriatic agent postoperatively is the key to avoiding and managing such situations apart from specific treatment for the underlying cause.

3. Cystoid macular edema (CME):

Cystoid macular edema (CME) following cataract surgery is a distinct entity. In

1953, Irvine described a syndrome following intracapsular cataract extraction associated with rupture of anterior hyaloid face. In 1966, Gass and Norton demonstrated cystoid spaces in the macula and optic nerve head staining using

FFA, after cataract surgery. Thus post operative CME is also known as the

Irvine Gass syndrome.

Pathogenesis:

Endogenous inflammatory mediators like prostaglandins, synthesized by intraocular cells subjected to surgical trauma has been said to play a major role in induction of CME. Lens epithelial cells have been found to synthesize these inflammatory mediators and the levels of prostaglandins has been found to be high as a result of cataract surgery. These mediators break the blood aqueous barrier and accumulate in the vitreous. They damage the blood retinal barrier and induce macular edema. Retinal capillary dilation occurs with serous fluid and cystoids spaces in the outer plexiform and inner nuclear layers. Muller cell

swelling and necrosis as well as extracellular collection of fluid are responsible for the formation of the cystoid spaces.

Normally the anterior vitreous face and the cortex act as barriers for diffusion of inflammatory mediators, however when there is vitreous loss following a posterior capsule rupture, there occurs vitreous liquefaction and the barrier is broken. Also anterior displacement of vitreous occurs. This leads to secondary changes in the perifoveal retinovitreal interface leading to CME (Schepens et al,

1984). This is more common in cases where detachment of the posterior hyaloid has not occurred. Iridovitreal adhesions also have a role to play in CME.

Management:

CME normally occurs at 6 weeks (Pollock) and resolves spontaneously by 6 months. Non steroidal anti inflammatory drugs (NSAIDS) which are prostaglandin inhibitors have been found to be useful in preventing as well as resolving CME (Solomon, 1995). They inhibit production of prostaglandins by blocking the cyclooxygenase pathway. These drugs may have to be administered from minimum of one month to several months depending on the duration of

CME.

Removal of vitreous if present in the anterior chamber, by Nd:YAG vitreolysis or anterior vitrectomy can help relieve the anterior traction on vitreous and reduce CME. Non resolving CME may require a pars plana vitrectomy and relieving of traction of the posterior hyaloid over the macula.

4. Retinal detachment:

The incidence of retinal detachment (RD) has been reported as 1- 6 % post any cataract surgery. Risk factors for retinal detachment include intraoperative posterior capsular rupture, vitreous loss and posteriorly dislocated nuclear fragments. Tielsch et al, in a multivariate analysis found that patients with intraoperative PC rupture had a 13 fold increased risk of retinal detachment.

Intraop vitreous loss is the most imp complication of cataract surgery related to

RD. The incidence of RD secondary to vitreous loss has been reported to be between 25-79 %

Pathophysiology:

Mechanical effects of cataract removal: Removal of cataract induces vitreous syneresis and liquefaction. Loss of the gel form of vitreous makes it prone not only to loss as in case of PC ruptures but also to easy movement into the sub retinal space when retinal breaks are present.

Structural changes in vitreous: There occurs a decrease in the levels of hyaluronic acid and increased liquefaction of vitreous following cataract surgery.

Complicated cataract surgery: Following vitreous loss, persistent traction over the vitreous base due to movement of vitreous anteriorly, adherence of vitreous to the wound or other anterior segment structures, traction following loss of lens fragments posteriorly and fibroplastic changes in the vitreous, can result in an increased risk of traction induced tears in the peripheral retina, followed by movement of the liquefied vitreous into subretinal space and subsequent retinal detachment.

Management: Surgery for retinal detachment should be done at the earliest to preserve visual function. Retina breaks may require an endolaser to avoid extension, parsplana vitrectomy followed by fluid air exchange and an air or gas tamponade to attach the retina is advisable.

5. Endophthalmitis: Risk factors for endophthalmitis following cataract surgery include: a) Duration of surgery greater than 60 min b) A temporal clear corneal section c) Poor wound construction d) Posterior capsule rupture and vitreous loss e) Persistence of lens matter f) Intraocular contamination

Diagnosis: Acute endophthalmitis usually manifests 2-10 days post operatively and presents as decreasing vision and increasing pain. Chronic endophthalmitis may have its onset weeks to months following surgery. Pathogens like staphylococci, streptococci, propionibacterium, gram negative bacteria or fungi may be responsible. Endophthalmitis is characterized by numerous signs like lid

edema, circum corneal congestion, iritis, hypopyon in anterior chamber (AC), posterior synechiae, fibrinous membranes or exudates in AC, plaque over intraocular lens, vitritis and vitreous exudates.

Management: First an aqueous or vitreous tap may help diagnose the etiology..

Frequent instillation of topical corticosteroids, fortified antibiotics and mydriatic agents, systemic antibiotics and corticosteroids, intravitreal injections and finally vitrectomy are the various modalities of treatment. The endophthalmitis vitrectomy study (EVS study, 1995) provided treatment guidelines for endophthalmitis management. EVS stated that systemic antibiotics are not very useful adjuncts to topical or intraocular therapy for endophthalmitis, however there were some controversies regarding this.

Fortified preparations of topical antibiotics include fortified vancomycin

(50mg/ml), fortified amikacin (20mg/ml) and fortified ceftazidime (50mg/ml).

Intravitreal injections generally include a combination of vancomycin, ceftazidime and dexamethasone for acute bacterial endophthalmitis and vancomycin, amphoterecin and dexamethasone for delayed onset cases. The following table shows the various concentrations of drugs used as intravitreal injections:

Drug Dosage

Vancomycin 1 mg/0.1 mL

Ceftazidime 2.25 mg/0.1 mL

Dexamethasone 0.4mg/0.1 mL

Amphotericin 0.005 mg/0.1mL

Vitrectomy helps to take out the vitreous membranes as well as pathogenic organisms, thus aiding recovery

6. Chronic uveitis:

Chronic uveitis lasting 12 weeks or more is generally associated with organisms with low pathogenecity like propionibacterium acnes and staphylococcus epidermidis. Features of chronic uveitis include anterior chamber reaction, presence of granulaomatous keratic precipitates and less often hypopyon.

Localized foci of infection may be present in the eye, mostly within the remnant lenticular capsule. Remnant lenticular material may contain a nidus of infection and may require removal when detected. Appropriate topical corticosteroid and antibiotic therapy should be given to manage the condition.

REVIEW OF LITERATURE

Several studies in the past have measured the outcome of phacoemulsification surgery following an intraoperative posterior capsular rupture. The following are a few:

1. Effects of posterior capsular disruption on the outcome of phacoemulsification surgery

In 1995, Mulhern et al described how introperative posterior capsule rupture can have an effect on surgical outcomes of phacoemulsification. This was a retrospective study of 43 cases that had a capsular disruption during surgery.

Apart from capsular disruption, capsular dialysis was also analysed. Some of the important results this study includes: a. Incidences of posterior capsule rupture and capsular dialysis were 86% and

14% respectively. b. Incidence of posterior capsular rupture was highest during nuclear phacoemulsification stage c. Anterior vitrectomy was required in 44% of cases

d. Only 25% had an in the bag fixation of PCIOL while 56% of cases had a sulcus fixated PCIOL and 7% were left aphakic. e. The major postoperative side effect was raised intraocular pressure (39%) followed by residual soft lens matter (23%). f. Nine months post operatively, 79 % of cases achieved a final visual acuity of

6/18 or better and 60% of cases had vision of 6/9 or better.

2. Visual Results and Complications of Posterior Chamber Intraocular

Lens Implantation After Capsular Tear During Phacoemulsification

Sumru Onal et al in 2004 published the visual results and complications of phacoemulsification complicated by posterior capsule tear. Both normal eyes

(159) and eyes that had had a capsular tear (58) during surgery were included in this study. Important results included: a. In eyes with posterior capsule (PC) rupture, 13.7 % had IOL inserted in the capsular bag and 86.3 % in the ciliary sulcus b. A mechanical anterior vitrectomy was performed in 77.5% of patients with capsular rupture. c. The final vision of 0.8 or better were more (86.8%) in the eyes that had uncomplicated surgery as compared to those with a PC rupture (63.8%)

d. In eyes that had complicated with a posterior capsular rupture during phacoemulsification surgery, it took longer time for refraction to stabilize as compared to uncomplicated surgery. The average time for final refraction was

190.0 ± 195.6 days in the eyes that had a capsular tear while it was 108.2±182.8 days in the eyes with an intact capsule e. Complications like an elevated intraocular pressure, decenteration of IOL, retinal detachment and cystoid macular edema were more common in cases with

PC tear as compared to uncomplicated cases.

3. Intraoperative Management of Posterior Capsule Tears in

Phacoemulsification and Intraocular Lens Implantation

Howard Gimbel et al in 2001 described management of posterior capsule tears intraoperatively and outcomes after surgery. Main results included: a. Among 83 cases with a posterior capsule tear, 50.6% of posterior capsular tears occurred during phacoemulsification followed by 39.7 % during irrigation- aspiration (I-A) b. The requirement for vitrectomy was more when the tear occurred during phacoemulsification (90.5%) than I-A (42.4%).

c. Fifty one cases i.e 61.5% of tears were converted to a posterior continuous curvilinear capsulorrhexis (PCCC), of which 98% had in the bag fixation of

IOL. One had PCCC with optic capture. It was hence concluded that small tears occurring at the end of phacoemulsification or during irrigation-aspiration can be converted to a PCCC to allow an endocapsular implantation of PCIOL

d. A best corrected visual acuity of 20/40 or better was achieved in 91.57% of cases with intraoperative posterior capsular tears as compared to 91.70% of cases without tears.

4. Visual outcome following posterior capsule rupture during cataract surgery

The visual outcomes of cases with a PC tear during cataract surgery were described by Ionides et al in 2001. Among 1533 consecutive cataract surgeries,

96% underwent phacoemulsification surgery. Main results included: a. There were 59 eyes with capsular tears and more tears occurred in surgical cases performed by surgeons in training. b. 41 out of 59 cases had to undergo vitrectomy during cataract surgry c. The cases with a PC rupture have a 3.8 times chance to have a final visual acuity less than 6/12 as compared with those with an uncomplicated surgery.

d. A best corrected post operative visual acuity of 6/9 or better was achieved in

14 cases of PC tear and 18 cases of PC tear and vitrectomy e. In the early postoperative period, macular edema was found to be the major reason for visual loss.

5. Short-term outcomes in eyes with posterior capsule rupture during cataract surgery

Chan et al in 2002 analyzed the outcomes in eyes that had a posterior capsule rupture during cataract surgery. The follow up was up to a postoperative period of three months. Eyes that underwent both ECCE (52 eyes) and phacoemulsification (90 eyes) were included in the study. Main results of the study were: a. Out of these 142 eyes, 140 cases had an IOL implantation, 65% were PCIOLs of which 10 were positioned in the bag and 54 in the ciliary sulcus and 35 % were ACIOLs b. 64.1% had vitreous loss requiring anterior vitrectomy and 35.9% of cases did not have any vitreous loss c.70.4% achieved a best corrected visual acuity of 6/12 or better between 6 weeks and 3 months postoperatively.

d. Cystoid macular edema (13%) was the major factor for poor vision postoperatively. e. The risk factors for a poor visual outcome were concluded as older age, coexistence of a ocular pathology, a ECCE surgery, an anterior chamber IOL implantation and introperative vitreous loss requiring anterior vitrectomy.

6. Effect and outcomes of posterior capsule rupture in a district general hospital setting

Ghee Soon Ang et al assessed how patients were affected after PC rent during phacoemulsification on a short term basis, in 2005. Major results were: a. Over the 2-year period, the incidence of PC rupture was 1.7% (45 PC ruptures in 2727 phacoemulsification cases) b. Thirty-eight eyes (84.4%) achieved a final BCVA of 6/12 or better. In 39 eyes (86.7%), final BCVA improved compared with BCVA at presentation.

c. The most common extra procedure was anterior vitrectomy (64.4%). d. The most common postoperative complication was raised intraocular pressure exceeding 30 mm Hg on the first postoperative day (20.0%).

e. Apart from 1 case of retinal detachment (2.2%) at week 27, all complications

resolved by 19 weeks and no patient required additional long-term medication at the final visit.

7. Visual outcome and complications after posterior capsule rupture during phacoemulsification surgery, 2000:

Eng-Yiat Yap et al, conducted a retrospective analysis of 44 eyes which had sustained trauma to the posterior capsule (41) and had a zonulysis (3) intraoperatively. The following were the results of this study: a. 41 eyes had vitreous loss i.e. 93.2 % and subsequent anterior vitrectomy was done. b. Twenty eyes had ACIOL implantation and the rest had a PCIOL. c.85.7% of the eyes achieved a best corrected visual acuity of 6/12 or better after excluding 2 eyes that had pre-existing conditions precluding good vision. d. The most common postoperative complication was corneal striae /oedema (26 eyes ) followed by a raised intra ocular pressure (6 eyes) and cystoid macular edema (5 eyes).

They concluded that even when phacoemulsification is complicated by a posterior capsule rupture or zonulysis, good visual outcome can be achieved with prompt management of complications.

8. Complication rates of phacoemulsification and manual small-incision cataract surgery at Aravind Eye Hospital, 2012

Haripriya Aravind et al, analysed 20,438 cases of phacoemulsification and

53,603 cases of manual small-incision cataract surgery (SICS) and tabulated the complication rates. The following were some of the relevant results: a. Posterior capsule rupture was the most frequent compliation associated with phacoemulsification as well as SICS in both the surgeon categories. A total of

126 PC ruptures occurred in the hands of staff surgeons out of 19337 surgeries

(0.49%) and 51 PC ruptures by trainee surgeons out of 1101 surgeries (4.6%), in the phaco group. This suggested a higher risk of PC rupture in the hands of trainee surgeons. b. Overall, most of the complications occurred during the step of quadrant emulsification for both trainee (77%) and staff surgeons (47%). c. The complication rates were comparatively low with both phacoemulsification and SICS in the hands of staff surgeons, however for trainee surgeons, complication rates were higher with phacoemulsification and hence SICS was suggested as a safer initial procedure to learn for inexperienced cataract surgeons.

AIMS AND OBJECTIVES

Aims:

The aims of this study are to describe the intrasurgical events and management strategies following posterior capsule rupture during phacoemulsification and to analyze the outcomes following surgery.

Objectives:

1. To document intraoperative events and management of eyes with a posterior capsule rupture occurring during phacoemulsification surgery.

2. To determine the number of eyes in which primary intraocular lens (IOL) was successfully placed and site of IOL placement

3. To document the secondary procedures required for these eyes.

4. To evaluate the postoperative complications.

5. To measure the postoperative visual outcome.

MATERIALS AND METHODS

Study design:

This study is a prospective observational study conducted at Aravind eye hospital, Madurai between June 2012 and January 2013 over a period of 8 months.

Patient selection criteria:

A. Inclusion criteria:

1. Eyes with senile cataract undergoing phacoemulsification surgery

2. Age more than 35 years

B. Exclusion criteria:

1. Combined procedures

2. Complicated cataract

3. Traumatic cataract

4. Corneal opacity restricting view

5. Lens induced glaucoma

6. Pre existing ocular pathology significantly impairing central vision other than cataract

Patients and methodology:

Patients undergoing phacoemulsification surgery at Aravind eye hospital,

Madurai between June 2012 and January2013, with intraoperative posterior capsule rupture were included in this study. Patient recruitment was done based on selection criteria.

A total of 91 patients were included in this study and had three follow ups postoperatively. Of these all patients turned up for the first follow up, however

2 patients were lost to the second follow up and 6 patients were lost to the last follow up.

Data Collection :

Preoperative data: Patients’ demographic data; vision, both uncorrected and best corrected visual acuity; anterior and posterior segment findings and intraocular pressures were recorded. Axial length, keratometric values and IOL power were determined using IOL Master. Hoffer Q formula was used for axial length of less than 22mm and SRK/T formula was used for axial length of

22mm or more.

Intraoperative data: The type of anaesthesia used, duration of surgery, surgical step at which posterior capsule rupture was noticed, other associated intraoperative findings or complications, intrasurgical maneuvers to manage the cases and the frequency and type of IOL implantation were documented.

Postoperative data: Patients had a follow up of three months, evaluation being done on postoperative day1 (POD1), day30 (POD30) and day90 (POD90). Slit lamp examination findings and intraocular pressures were recorded.

Complications following surgery were documented. Any secondary procedures done were described. All patients were given a course of topical corticosteroids for six weeks and topical antibiotics for three weeks. At post operative day 30, topical non steroidal anti-inflammatory drugs were given for four weeks. Apart from this regimen, based on the postoperative complication, drug dosage and duration were altered and any additional drugs that were prescribed to patients were mentioned. Vision, both uncorrected (UCVA) and best corrected visual acuity (BCVA) were recorded at follow up. At POD1, vision with pinhole was measured (VA with PH)

Statistical Analysis:

Mean (SD) and Frequency (percentage) was used for continuous and categorical variables respectively. Student t-test or Wilcox on sign rank sum test was used

to assess the difference between the continuous variables. Fisher’s exact test or chi-square test was used to assess the difference between the categorical variables. A p-value of less than 0.05 was considered as statistically significant.

All the statistical analysis was done by statistical software STATA version 11.0.

RESULTS

1. Age distdistribuibutiioon (fiigg..1):1):

AAggee (y(years)ears) distribution(n=91)

Frequency Percentage

52.8 45 48 2.2 41 2

<40 40-60 >60

Of the 91 casaseses in tthhis studstudyy,, moorere thaann hahalf of ththe patitienentsts (5252..88%)%) wweerere

betwbetweeeen 4400 aannd 60 yyeearsars of age.

2. Gender ddististribributioonn (figfig..2):2):

Gender distribution (n=91)

Females 42% Males 58%

Of 9911 ppaattiennttss,, 38 (42%42%) weerre ffeemalealesales andnd 5533 ((5588%)8%) were malalees.

3. Systemic illness (fig.3): The frereqquuency aandnd ddististribibuutttionioonn of systesystemicic iillllnlneessssss prevavaililiningg iinn the sttuudyuddy popoppululaattioion iiss as folloollowws:s:

50

40

30

20 Frequencyquency Percentage 10 OthersOthers include asasthma,ma, cardiiacac 0 iilllnesess and None DDiiabetesabetes Hypertens Others ion vavaricossee veins Frequency 42 27 19 15 Percentage 46.2 29.729.7 20.9 16.5

4. Laterality (fig.4): ThThere wwerere 48 rigrighhtt eyes anndd 43 left eyes operaratteded

NNuumbbeerr(n(n=91)=91)

48 46 44 42 40

Number Right eye Left eye NNuumbberer 48 43

5. Baselinine BestBest cocorrerectcteedd visual acuity (BCVA) measured before susurggeeryry showedwed a lalarrge nunumbbeerr of patitientnts (4400..77%%) withth vvisiissiioon betwetweeen 6/6//66 and 6/6/112

(table1):

BBCVACVA Baseline 6/6-6/12 37(40.7 %)

6/18-6/36 36(39.5 %)

<=6/60 18(19.8 %)

Total 91

6. Catararacctt grooupupups andand cororrrespoespondiespondinding visusual accuiuity is aass fofolllloows (figfig..5):5):

Coorrrelation ofof typetype ofof cataract with BBCCVA 90.00% 80.00% 70.00% 60.00% 50.00% 40.00% 30.00% 20.00% 10.00% 0.00% 6/6-6/12 6/18-6/36 <=6/60 Nuclear Sclerosis/Cortical/Sub 83.80% 80.60% 61.10% capsular Hard/Advanced Cataract 2.70% 5.60% 33.30% Posterior Polar Cataract 13.50% 13.80% 5.60%

There were 9 patients with hard/ advanced cataracts, 11 with posterior polar cataracts and the rest of the cataracts were not fairly advanced. Both hard/advanced cataracts as well as posterior polar cataracts are risk factors for

PC rupture. Three eyes (3.3%) had a shallow anterior chamber and three (3.3%) had pseudoexfoliation which are also risk factors for PC rupture.

7. Axial length distribution (table 2):

Axial length (mm) Frequency Percentage <21 0 0 21- 24 74 81.3 >24 17 18.7

Total 91 100.0

53 eyes (58.2%) were operated under topical anaesthesia (kinetic) and 38 eyes

(41.8) under retrobulbar anaesthesis (akinetic).

8. Frequency of posterior capsule ruptures and vitreous presentations (fig.6): Posterior capsule rupture was noted with equal frequency during the step of nuclear quadrant emulsification (29.7 %) and step of irrigation-aspiration

(29.7%). There were 55 cases of vitreous loss (disturbance), of which 38.3 % occurred during emulsification followed by 23.6% that occurred during irrigation-aspiration.

40 21 35

30

25 13

20

15 7 n=91 10 1 5 Step Vitreous disturbance 5 2 2 0 n=55

9. Intraopeaoperraattive finnddidinggs/s/coompmplicatioations assoassociaiatteedd witthh postpostetereriioor caapsupsulle rupture (fig.7):

In this study,y, tthhereere wereere 5555 patients withth vitreous llossoss and 12 patitients wwiitthh loslosss of lelens frragagmentsents or IOLIOL posteposteriorly of whihich 7 patieenntsnttss hadad nnuclucleusus droopp,, 4 hhadad cortex ddrrop andnd 1 ppaattient hhaad IOL drop. Nine patients (9.9%) unnddererwewenntt parsplana vitrtreecectctotomy combbiinneded wiitthth parparsplplanalennsenssecttoomy/cy/coorrtrtex reremoval/IOL extraction for posoststtererioior disdisllococcaatitionon of nucnucleueus//ccortortrtexex/I/IOOLL resespecpectivveelllyy. ThisThis proprocceedurere wwaas perperfoformeedd byby a vitreoretinanall susurgeonon on thehe ssaame daday aass thehe primary surgery.

Intraaoooppeperaattive fifinndidinng/coompomplimplicacatioatiotionns inin ppatientspatienatients withwiitth PC rruptruuptuptuure (n=91)

60 55

40 30

20 7 4 6 0 7 4 1 2 No. No.

Others include 1 cascase ofof zoonnularular ddiialysisiss and 1 cacassee ofof retinnaal breeakak

10. Vitrectomy:

80% of the cacaasseseses (4444 eyes)yes) with vitrreeooususus lossoss undeuunderwnderrwwent automatatedted antanteerrioiorr vitrectomy and (200%%)) underwunderwenentt parsplana vitrecttoomy ((111 eyeyess).).

11. Additionaonall intraasursurgigical mmaanneuvers (table 3): AAffter ococcurcurrreennce of PC rupture, a fewew addidittiioonnaall maneuvers were done in order to proceproceeded withth ththee surgery as shown below:

Maneuvers Frequency Percentage Sphincterotomy 1 1.1 Iris hooks used 4 4.4 Iridectomy 2 2.2 Section Enlargement 14 15.4 Alternate Section 5 5.5 Pilocarpine used 17 18.7 Sutures 55 60.4

Alternate section made was a superior sclerocorneal tunnel. No cases were converted to Extracapsular cataract extraction.

12. IOL type (fig.8):

70 eyes (77%) had a foldable hydrophobic acrylic IOL, 12 eyes (13%) had a foldable hydrophilic acrylic IOL and 9 eyes (10%) had a rigid polymethylmethacrylate IOL (PMMA).

IOL

PMMA 10%

Hydrophilic acrylic 13%

Hydrophobic Acrylic 77%

13. PCIOL location (fig.9):

PC IOL Location

Apahakia 4% In Bag 30% In Sulcus 66%

59 cases (65%) had ciliary sulcus placed IOL, 27 cases (30%) had in-the-bag placement of IOL and in 4 cases (4.4%) no IOL could be placed primarily

(aphakia). All the sulcus placed IOLs were three piece either PMMA or

hydrophobic acrylic type. Of the 5 cases that had primary aphakia, 3 cases had a secondary IOL that was placed in the sulcus by a vitreoretinal surgeon on the same day and in 1 case, iris fixated IOL was placed on a later date.

14. Significant findings on postoperative day1, day 30 and day 90 (POD)

(table 4):

On POD1, only 36 % of patients had clear corneas, loss of corneal clarity mainly attributed to epithelial edema and striate keratopathy. With subsequent resolution of this condition, the percentage of clear corneas improved to 97.6% on POD90. Abnormality in pupil shape was attributed to presence of vitreous in the anterior segment. The frequency reduced from 8.8 % on POD 1 to 7% at

POD90 after secondary procedures like anterior vitrectomy and Nd:YAG vitreolysis were done.

Iritis was higher in the immediate post operative period and subsequently settled down with corticosteroid regimen.

Lens fragments were present in as much as 14.3% of eyes at immediate post op; however reduced to just 2.3 % at the final follow up due to absorption of soft cortex or removal by a repeat surgery. Vitreous in anterior segment was seen maximally at POD30 (16.8%). This number reduced at POD90 (13.2%) due to secondary procedures like vitrectomy and Nd:YAG vitreolysis.

Table 4:

POD1 POD30 POD90 Anterior segment n % n % n % Cornea Clear 41 36.0 82 92.1 83 97.6

Epithelial edema 29 25.4 3 3.3 1 1.2

Striate Keratopathy 37 32.5 2 2.3

Pupil Contour abnormality 8 8.8 10 11.2 6 7.0

Iritis 58 64.8 17 19.1 11 12.9

Lens matter in anterior segment 13 14.3 9 10.1 2 2.3

Vitreous in anterior segment 8 8.8 14 16.8 12 13.2

15. Post operative complications and their presentation (fig.10):

The distribution of postoperative complications encountered in this study is shown in the figure 10. A raised intraocular pressure (IOP) (>21mmHg) was the most frequent complication seen in 10 patients (11%), followed by macular edema seen in 6 patients (6.6%). Striate keratopathy was not included in this list because in most of the cases, it was transient lasting only for one or two days.

ThTheerre weerere twowo cacaasseseses of endndoophthphthalmiititis inin our stududyy,, oonne ooccccurrurreded atat POD 35 and the ootthherer atat PPODOD 1414, bobotthh of whichch reeccooververeded bbyy a combibinatiioon of ssysystetemicic anndd totopitopiccalal ththerraapy aass wewellll as intravitrerealal injeinjeccttiiiooonn.n. No ssuurgrgiicicalal prococededurure wwaaass required. ThThee foollollowining tablble (5) rreeppresresentnts the ddiistributtiioon of complicatitioons over various time periods:

Frequency

10 9 8 7 6 5 4 3 2 Frequency 1 0

Complication presentation Frequency Before day 7 (1 patient) Raised IOP 1 Day 7 – 30 (13 patients) Macular edema 3 Raised IOP 7 Endophthalmitis 1 Chronic corneal edema 1 Lens matter induced vitritis 1

After day 30 (11 patients) Macular edema 3 Raised IOP 2 Endophthalmitis 1 Chronic uveitis 3 Late post-op iritis 3

16. Correlation of retained lens matter in anterior segment or Iritis with development of raised IOP (fig11):

A higher percentage of patients who presented with lens matter in Anterior

Chamber (AC) or iritis postoperatively, developed a raised IOP compared to those with a normal AC both at POD 30 and POD 90 (23.8 % and 15.4 % respectively).

CCororrelaelattionion ofof LLeens matter or Iritis eitherither presenent oror absabseent in with raisseed IOP

Raised IOP

Yes No

93% 76% 84.60% 88.90%

23.80%

7.40% 15.40% 11.10%

Present -Day 30 AbAbssent - Day 30 n=21 n==6868 Present -Day 90 n= 13 Absent -Day 90 n=72

17. CCoorrrrelationon ooff Vitritreeousus in anteanterior segmegmenent with raiseised IIOPOP (fig12)

A hhiigghheerr perercceenttaaagge of patitienntsts (2(25%)5%) wwhoho preressesenntted wiitthh vitvitrreeoousus iinn thehe anterior sseegmenentt ppostoostoperstoperperatatitivvelyly,, develoopped a raraisisisededed IIOOP cocomparpareded toto thosese with no vitreous (7%) inin anterior seeggment (p=0.0.0038)

VVititreoeous iinn anteeririoorr segment versus raiseedd IIOPOP Raised IOP Normal IOP

93% 75%

25% 7%

Viitreoutreous prepresseentnt Vitreous absent

n=20 n=71

18. Correlatioationn ofof VitrVitreeoousus inin anterierior segment witwith macular eddeemama (fifigg.. 13)

VVititrreouous in aanntterierioror segegmmentent versus mmaculacularar edema Macacuularlar edema No macular edema

85% 96%

15% 4.2%

n=20 Vititrereouous presentent Vitreous absent n=71

A largegerr peperrccennttage of paattienntsts whwhoo ppreresesseenntteed wiwitthh vvitititrreeoousus ppoosttoperoperatattivivivelyely,, developed a maccululaarr eddeema cocompparareed to thoosse wwiitthh no vitreous in anterior segment (p=0.118).

19. AsAssociiaationon ooff mmacuacular eededemma with intraraooppeerratiivve poposteterteririor diisslolocataatiotionn of lens fragagmmentsents or IOLIOL( fifigg 14)

Inncciiddenceence ooff macumacullaar edema in patients wiwithth or withhoouutt posteriioorr dislocacatiotion of lens frfraagmgmeentsnts oror IIOLOL

Macular eddeema No macular edema

75% n=12 96% n=79

25% 3.80%

Posteeriorrior ddisislococaattiionon preseesennt Posterioror dislocation absent

A greateterr perpercceennttaagge ((2255%%) of paatttiienntts who had intntrraaopeerraattiivvee ppostoststerior ddisislolocatcatioionn of lennss frfraaggmentseenntsts or IIOLOL , prpresesentententeedd witiiththh macculacuulalarr edema ((33 outut of

12) postoperativevely (p=00..0028)

20. Association ooff macullaar edema with intraoperatiivve vitreeoousus loss ((ffigig15)15)

Of 55 ppaattienentsttss wwiitthth vitvititrereousous loss anndd 3366 paattienntststs wiiththohoutut vvititrreeoousus llossossoss, 3 devveelloped maculacularr ededema iinn eacach ccaategory. There wawaass nono signignificanicant corrorrelalatiotitioon between vvitritreoeousus llossoss and maculalarr edema (p=0.678)

MacMacuularlar eededema versus vitvitreeououss loloss

Macacuularlar edeedema No macular edema

95% 92%

6% 8.30%

Vititrreoeouus loossss No vitreous loss

21. Secondary procedures (fig 16)

Thirty pattiientents unndederrwenwent sesecoconndary procedureduress of whhiich pars plana vitrectomy was the most frequent (11%). There wewerree ttoottalally 9 casaseess of either parparssplaplannaa lenselensectctomy or coortrtrtexex rreemoovavvaall.. Two patatiieenntts whwho dedeveelloopepeded enendonddoopphhhththalmitiitis received intravitreaeal iinjnnjjeectctiioons.s. LaLasseer Nd:YAGYAG vvitititrreeoollysilysiysis wwawasas done iinn 8 ppaaattitients due to presentationon of vitrvitreous iinn ththe antteeririor chamberber paparrtiticucullaarrly at the section postoperativivelely, ththrereateniningg to cause retinal ttraracction. TThhreeree of these laser

procedures ttooook plalacece betwtweeeen 1 weweeek anndd 1 month aaffter susurgery and five totook ppllace beyoyonond one montthh afaftteerr surggeerryy. FoFouurr ppaattientnts hhaad a sseeecconconddaarrryy IOIOLL,, tthrhreeee on the sasame daayy anndd oonne aafftteerr oonne moontnthh post op.

OtheOther procproceduredurees:s: 67 70 61 2 antteerrioror segmementnt washwash to remove retetaineded lensns matmattter 60 1 IOL explannttationtion 50 1 endolaser fforor retiinnaal bbrreak 40 1 YAG PePeriipherpheral iriidotodotomy

30 1 partial gagass release

20 11 10 9 9.9 8.8 8 6.6 10 5 5.5 6 2 2.2 2 2.2 0

Frequency Percentage

22. Additional drugs: (figig 17)

Apart frorom the rroouutitinnee cocortiticcosteroid regimen give for 6 weeks and non steroiiddal anti-infllaammmmaattoorry ddrrugugs ((NSAIDS)NSAIDS) given for 4 wweeeeeksks, 6644 ppaattieennttss neeedded adddititionalal drugugs aaffter susurgeryry mainainly duduee toto seseccoondandarryy prococededureuress doonne or for treatmenent of compplpliliicacattiioons thatat ththey developloped.eded. OOff thestthehessee exxtrtra drugs,s, NSAINSAIDDS were most frequentltlyy usused drdrugs followed bbyy anantti glaucoma mmeeddicatatiionon.. Other drugs ininclclude topipicaall hhyypertotoninic agents anndd mydriatticics.s. The doosagsage of stesterroids had to be increcreasased in 22 eyyeess (2(24 %) postotoperperatively.

50 45 40 35 30 25 20 15 Frequency 10 Perrccententage 5 0 27 41 22 7 2 20 22

23. BBCCVVAA coompamparriissonsoon bbeettweenen baaseselelinine (prpreeoopepeperrativive)e) aandnd ppostooostopstopeerraatiattiveve values: (fig18)

PPrre andnd pospostoopperative BCVA comparompariison

100.00%

80.00%

60.00%

40.00%

20.00%

0.00% BBasaseliline Day 1 1 month 3 months <=6/60 19.80% 16.50% 1.10% 0% 6/18-6/36 39.50% 17.60% 3.40% 3.50% 6/6-6/12 40.70% 65.90% 95.50% 96.50%

At babasese liline, therhere werweree almoostst eeqquaual nunumber of patatienntts (n=(n=3737) withth vviisiosion between 6/6-6/12 and 6/18-6//336 (40 % in eacchh group). However at finalal follloow up, 8282 (9966.6.5%)5%) patieientnts hadad BCVABCVA of 66//1212 or moorere whwhiicchh wasas sigsignniificaicantntlyly hihiggheheherr ththan the babasbasese line valuluee.. Of 82 patients,s, 6699 (8(84.4.1.11%%)) patitieentnts had BCVBCVAA of more than 6/99.. Therree wewerree no patitients with visvision 6//660 or worse.se.

24. Correlationon ooff cornorneal clarity with BCVA at POPOD1:D1: (fig19)

At first followllowow uupp,, 3311 papatattiientnts had visivisioonn ofof 6/1/188 or worsorseorse, of whihich aboouutt 933%% had ppooroor cocorneealal clclarity ssuuguggesting poorpoor ccllarityty of tthhe coorrneeaa toto bebe thhee cacauseuse for poor vision (p<0.001).

CCororrelaelattionion ofof corornneaeall clarity on dayay 1 withwith BCBCVA

100%

80%

60%

40%

20%

0% 6/6-66/12/12 6/18-6/36 <=6/60 Not clear 3535.00% 93.80% 93.30% Clear 6565.00% 6.20% 6.70%

25. Correlrelatioionion bbeettwweeeenen BCVABCVA at PODOD9090 and ppososostt opopeerraratiivve compompliplicatatioonsns

(fig 20):

21 patientsts had ppososost ooppereraratatiivve comppllilicatiioonsns, of whiwhichicch 3 (1144.4..22%2%) had mooderderate visual loss (BCVA 6/18-6/36) at POD90D90 wwhihilele aallll thhososee witthhoouutt anany complicaattiions haadd a visvisiioon of 6/1122 or betteetter.r. Thihis susugggests a positive cocorrerellaattiioon betweeeen subbopoptimalal visivisionisionon anndd prepresesencence of pposostotopopererraativeve complipliccaatiottiioon

(p=0.013.013).013)).. The ccaaususe for ththe poor visisioionn atat PODPOD 9900 in ttwwo eyyeses wwaasas maculaaculalarr edema andnd inin onone eye itit wawas cornenealal decompensation due ttoo chroronini c edeedema.

CorCorreelalattiionon of BCVA on day 90 witthh coomplmpliicacatiotions

100%

95%

90%

85%

80%

75% CoCommpplilicatitioonns Complications absent present 6/18-6/36 0 14.20% 6/6-6/12 100% 85.80%

DISCUSSION

Posterior capsular rupture during phacoemulsification is the most frequent of the significant complications occurring during cataract surgery. In this study there were 91 eyes that had phacoemulsification surgery complicated by a posterior capsular rupture. On preoperative anterior segment evaluation, three eyes (3.3%) had a shallow anterior chamber and three (3.3%) had pseudoexfoliation which are risk factors for PC rupture (Rasik Vajpayee et al, 2001). The other risk factors noted included high myopia (3.3%), hard or advanced cataract (9.9%), posterior polar cataract (12.1%) and diabetes mellitus (29.7%). Posterior polar and advanced white cataracts (Brazitikos et al, 1999) have been reported as significant risk factors for a PC rupture. The incidence of PC tears ranges from

6% to 36% in eyes with posterior polar cataract as reported by Hayashi, Osher and Vasavada et al in separate studies. In this study the grade of cataract distribution analysis showed that most of the patients (78%) had cataracts that were not fairly advanced.

Fifty three eyes (58.2%) were operated under topical anaesthesia (kinetic) and

38 eyes (41.8) under retrobulbar anaesthesis (akinetic). Richard Lee et al in 2013 reported the incidence of posterior capsule rupture with akinetic and kinetic techniques of anaesthesia and concluded that there was no clinically or

statistically significant difference in the risk for posterior capsule rupture between these two techniques. The mean duration of surgery was 20.4 and 20.6 minutes respectively for those under topical and retrobulbar anaesthesia .

Posterior capsule ruptures have been reported to occur at different steps of phacoemulsification surgery. Mulhern et al in 1995 and Ghee Soon Ang et al in

2006 reported the incidence of PC tears to be highest during the stage of nuclear phacoemulsification (48.6 % and 42.2% respectively). Similarly Howard

Gimbel et al in 2001reported the frequency of PC tears to be highest during the step of phacoemulsification followed by irrigation–aspiration i.e. 50.6 % and

39.7% respectively with a higher incidence of vitreous loss associated with the former ( 90.5% versus 42.4% ). In our study, posterior capsule rupture was noted with equal frequency during the step of nuclear quadrant emulsification

(29.7 %) and step of irrigation-aspiration (29.7%) (fig.6) of which vitreous loss was associated more with the former step (38.3 % versus 23.6%). A total 55

(60.4%) cases had vitreous loss. Out of the cases with vitreous loss, anterior vitrectomy was done in 44 cases (80%). The other eleven cases (20%) underwent parsplana vitrectomy. In a similar study conducted by Fiona Chan et al in 2003, of the 90 eyes that underwent phacoemulsification complicated by an intraoperative posterior capsule rupture, 54 cases had vitreous loss (60%) and all required anterior vitrectomy (100%).

Posterior chamber intraocular lens was successfully placed in 87 eyes (95.6%).

The remaining 4 eyes (4.4%) in which no IOL was placed primarily, a secondary IOL implantation was done. There were no eyes with an anterior chamber IOL. Twenty seven out of 86 eyes had a in the bag placement of IOL

(31.4%) and 59 had a ciliary sulcus placed PCIOL (68.6%) (fig.9) suggesting that in cases complicated with a PC rupture, a ciliary sulcus placement is preferred to avoid further damage to the PC. All the sulcus placed IOLs were three piece either PMMA or hydrophobic acrylic type. No significant decenteration of PCIOL, affecting vision or requiring a resurgery was noted in any of the cases. Previous studies suggest a range from 13.7% to 61.45% for in the bag placement of IOLs (Sumru Onal et al, 2004; Ghee Soon Ang et al, 2006;

Mulhern et al,1995; Howard Gimbel et al, 2001) and a range from 56% to

86.3% for sulcus placed IOLs ( Mulhern et al,1995; Ghee Soon Ang et al, 2006;

Sumru Onal et al, 2004). Lack of enough posterior capsular support, risk of enlarging the tear, risk of posterior dislocation of IOL by attempting in the bag placement are a few factors why surgeons place the IOL in the ciliary sulcus. An intact anterior capsulorrhexis is the most important requirement for a ciliary sulcus placement. Howard Gimbel and colleagues reported that with the conversion of a posterior capsular tear into a posterior continuous curvilinear capsulorrhexis, a successful in the bag placement of IOL can be achieved in

most eyes. However this technique was not followed in any of our cases. In one case where the PCIOL was places in the sulcus, the optic of the IOL was captured in the anterior capsulorrhexis opening. This technique was first described by Neuhann and Neuhann in 1991.

Apart from anterior vitrectomy, a few additional maneuvers were done intraoperatively in order to proceed with surgery after the posterior capsule rupture occurred. .This included use of iris hooks/ multiple sphincterotomies to deal with constriction of pupil; enlargement of section/ making a separate section to remove the nucleus or place IOL; use of pilocarpine, to check for remnant vitreous , use of sutures to secure the wound tightly and use of intravenous mannitol to combat positive vitreous pressure (table 3). In one case of PC rent associated with a zonular dialysis, placement of capsule tension ring was done in order to support to the bag .Of these maneuvers, the use of sutures was most frequently performed.

A raised intraocular pressure (11%) was the most frequent post operative complication (fig.10), followed by macular edema (6.6%). In a similar study done by Mulhern et al, raised IOP was found to be the most frequently encountered postoperative complication (39%). Macular edema has been reported to have an incidence of 10.7% in cases of posterior capsule rupture as reported by Periklis Brazitikos et al in 2002. On the other hand, Mulhern et al

and Gimbel et al reported no cases of macular edema in such cases. There were two cases of endophthalmitis in our study, both of which recovered by a combination of systemic and topical therapy as well as intravitreal injection. No surgical procedure had to be done.

A greater percentage of patients who presented with lens matter in anterior chamber (AC) or iritis postoperatively, developed a raised IOP compared to those with a normal AC both at POD 30 and POD 90 (23.8 % and 15.4 % respectively).

Also a larger percentage of patients (25%) who presented with vitreous in the anterior segment postoperatively, developed a raised IOP compared to those with no vitreous (7%) in anterior segment (p=0.038). This suggests that increased inflammation especially due to retained lens/vitreous in AC causing

IOP rise.

A larger percentage of patients who presented with vitreous postoperatively, developed a macular edema compared to those with no vitreous in anterior segment (p=0.118). Similarly a greater percentage (25%) of patients who had intraoperative posterior dislocation of lens fragments or IOL, presented with macular edema (3 out of 12) postoperatively (p=0.028). This highlights the positive relationship between anterior vitreous movement/ vitreous disturbance

due to posteriorly dislocated lens fragments or IOL and development of macular edema.

Thirty patients needed post operative secondary surgical or laser procedures

(fig.16) depending on the intraoperative and postoperative complications present. Ten patients (11%) underwent parsplana vitrectomy combined with parsplanalensectomy/cortex removal/IOL extraction for intraoperative complications like posterior dislocation of nucleus/cortex/IOL respectively. This procedure was performed by a vitreoretinal surgeon on the same day as the primary surgery and in three cases that were rendered aphakic primarily, a secondary IOL was placed by the VR surgeon. One patient had a secondary iris fixated IOL. Eight patients (8.8%) underwent laser Nd:YAG vitreolysis for presence of vitreous in the anterior segment. Three of these laser procedures took place between 1 week and 1 month after surgery and five took place beyond one month after surgery.

Apart from routine post operative medication, 64 patients (70.3%) received additional drugs (fig.17) for different durations, for various reasons like corneal edema, raised IOP, cystoid macular edema, endophthalmitis, increased inflammation and post secondary procedures. Forty one patients required non steroidal inflammatory drugs. These drugs were given to reduce inflammation, prevent as well treat cystoid macular edema. They were preferred over

corticosteroids as steroids can cause raise in the IOP, dependence as well as rebound phenomenon on discontinuation. Twenty two patients received anti glaucoma medications to combat corneal edema, striate keratopathy as well as raised IOP. Oral anti glaucoma therapy was supplemented for severe corneal edema and striate keratopathy.

The final visual acuity (BCVA at POD 90) distribution showed 96.5% (n= 82)of patients to have vision better than or equal to 6/12 of which 84.1% of patients had vision better than 6/9 (n=69). Similar studies done previously gave the following results:

Authors Cases with BCVA≥6/12 Percentage

Eng-Yiat Yap et al, 1999 36 out of 44 cases 81.8%

Fiona Chan et al, 2003 72 out of 90 cases 80%

Ghee soon Ang et al 38 out of 45 cases 84.4%

At the first follow up only 65.9% (n=60) had vision better than or equal to 6/12.

This was attributed to poor corneal clarity (34.1% of patients) significantly due to epithelial edema/striate keratopathy (p<0.001). With subsequent management with both topical and systemic anti glaucoma medications as well as

hyperosmotic agents, the percentage of clear corneas improved to 97.6% on

POD90.

In the study conducted by Eng-Yiat Yap et al, in 1999, 26 out of 44 eyes (59%) developed corneal striae/edema postoperatively. It was the most common postoperative complication, however it was transient and none developed bullous keratopathy.

Of 21 patients with post operative complications, 3 (14.2%) had moderate visual loss (BCVA 6/18-6/36) on POD90 while none without complications fell into this category. This suggested a positive correlation between suboptimal vision and presence of postoperative complication (p=0.013) complication.

In this study, only one patient had final BCVA worse than the baseline BCVA subsequent to macular edema. 69 patients achieved a BCVA of more than 6/9

(75.8%) at final follow up suggesting a good outcome of the surgery.

CONCLUSION

Loss of integrity of the posterior capsule during phacoemulsification surgery is not an unknown entity. Although it can happen in any situation, surgeons should be aware of the risk factors for an intraoperative posterior capsule rupture and recognize the signs early. The important results of this study are summarized as follows:

1. PC rupture was found to occur most frequently during the step of nuclear

emulsification and irrigation-aspiration of cortex.

2. Appropriate intrasurgical management ensured that a posterior chamber

IOL was placed successfully in the eye. Most of the PCIOLs were placed

in the ciliary sulcus.

3. Vitrectomy was essential for all cases with vitreous loss to avoid serious

complications associated with presence of vitreous in the anterior

segment. In this study, more than half of the patients had vitreous loss and

subsequent vitrectomy.

4. Most frequent post operative complications included a raised intraocular

pressure followed by macular edema.

5. Postoperatively, several patients needed additional surgical /laser

procedures and additional topical or systemic medications to deal with

complications.

6. In the immediate postoperative period, patients had lower initial visual

acuity due to corneal edema, however a majority of them recovered and

achieve a good final visual acuity with medical therapy.

7. In this study, only one patient had final BCVA worse than the baseline

BCVA subsequent to macular edema. A large number of patients (96.5

%) had vision of 6/12 or better at final post operative follow up.

Thus, with appropriate management, phacoemulsification surgeries complicated by a posterior capsule rupture can have good outcomes.

Phacoemulsification machine and various phaco tips

FolFoldabledable PCIOLPCIOL Implanplantatationtion

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ASSESSMENT FORM FOR SURGICAL OUTCOME FOLLOWING POSTERIOR CAPSULE RUPTURE DURING

PHACOEMULSIFICATION SURGERY

Study no: Hospital no: Name: Age: Sex: ___ [Male-1; Female-2] Co existing ocular pathology: ___ [None-0; Glaucoma-1; Retinal Pathology-2; Others (specify)-3] Systemic illness: ___ [None-0; Diabetes -1; Hypertension-2; Others(specify)-3 ]

PRE OPERATIVE EVALUATION

Eye to be operated: ____ [Right-1; Left-2] UCVA: ____

Spherical correction Cylindrical correction Axis of cylinder BCVA

VA with PH (when no refractive correction): ____ Examination: Pupil ____ [Normal-1; Small-2] Anterior chamber ____ [Normal-1; Shallow-2] PXF ____ [Absent-0; Present-1] Cataract ____ [Nuclear sclerosis/cortical/subcapsular-1; Hard/advanced cataract-2; Posterior polar cataract-3] Fundus: ____ [Normal-1; Abnormal(specify)-2;hazy media but other eye normal; hazy media but other eye abnormal(specify)- 4]

Intraocular Pressure: ____ mmHg Axial length: ____ mm Keratometry: K1 _____D Axis _____ K2 _____D Axis _____ Power of IOL: ____ D

INTRA OPERATIVE EVALUATION

Date of surgery: __/__/____ Surgeon Category: ____ [<5 yrs Phaco experience-1; >5 yrs Phaco experience-2] Type of Anaesthesia: ____ [Topical-1; Retro bulbar block-2] Type of IOL: ____ [PMMA-1; HEMA-2; Acrylic-3] IOL changed: ____ [No-0; to PMMA-1; to Acrylic-2] Duration of Surgery: ____min Phaco time: ____ metrics

Step at which PCR was first noticed: ____ [Anterior capsulorrhexis-1; Hydroprocedures-2; Phaco I- 3; Phaco II- 4; Epinucleus Removal- 5; Irrigation and Aspiration- 6; IOL Implantation-7; Others (specify)-8; Not assessable- 9]

Intra Operative Findings/Complications: _____

None 0 Positive vitreous pressure 1 Small pupil 2 Extension of Capsulorhexis 3 Vitreous disturbance 4 Nucleus drop 5

Cortex drop 6 IOL drop 7 Others (specify) 8

MST done: ____ [No - 0; Yes-1] Iris hooks used: ____ [No-0; Yes-1]

Iridectomy done: ____ [No-0; Yes-1]

Section Extension done: ____ [No- 0; Yes-1]

Sx technique converted: ____ [No-0; Yes (specify)-1]

PCIOL placed: ____ [None-0; In Bag-1; In Sulcus-2; Not assessable-4]

Vitrectomy: ____ [None-0; Anterior-1; Parsplana-2]

Pilocarpine used: ____ [No- 0; Yes-1]

Sutures applied: ____ [No- 0; Yes-1]

Other procedures: ____ [Nil-0; Done (specify)-1]

Senior surgeon’s assistance taken: ____ [No-0;Yes-1]

POST OPERATIVE EVALUATION

POD1 POD30 POD90 UCVA Spherical correction Cylindrical correction Axis of cylinder BCVA/ VA with PH Wound [WA- 1; Gape/leak – 2; others-3]

Cornea [Clear-1; Epi.edema-2; DM folds -3; DM strip or defect - 4; Epi.defect / burn-5; SK-6; others-7] AC [WF - 1, Shallow – 2] Pupil [Normal-1; peek-2; Abnormal (specify)-3] Iritis [None -0, Mild - 1, Moderate -2, Severe-3, not assessable-4] Cortex/ Nucleus [Absent-0; cortex present-1, nucleus present-2] Vitreous [Absent-0; In PC-1; at pupil-2; In AC-3; touching cornea-4; In section -5] PCIOL [Aphakia-0; in bag-1; in sulcus-2; Decentered-3; Dislocated-4; Optic capture-5; not assessable-6] OTHERS [None-0; Yes-1(specify)] Fundus [Normal-1; Abnormal (specify)-2; Not assessable- 3] Intraocular pressure(IOP) in mm Hg

Complications: _____ Detected on: ____ [Before POD7-1, POD7 to POD29-2, POD30 to POD59-3, POD60 to POD90-4] None 0 Macular edema 1 Glaucoma 2 Endophthalmitis 3 Retinal tear 4 Retinal detachment 5 Chronic uveitis 6 Others (specify) 7

SECONDARY PROCEDURES: ____ [None-0; anterior vitrectomy-1; Parsplana Vitrectomy-2; Parsplana lensectomy-3; Intravitreal Injection-4; Yag vitreolysis-5; Suture removal-6; Secondary IOL-7; others (specify)-8]

Done on: _____ [Before POD7-1, POD7 to POD29-2, POD30 to POD59-3, POD60 to POD90-4]

Additional drugs: ____ [None-0; NSAIDS-1; Anti Glaucoma drugs-2; Others (specify)-3]

Advised on: ____ [Before POD7-1, POD7 to POD29-2, POD30 to POD59-3, POD60 to POD90-4]

Duration: ____ [Less or equal to one week-1, one to two weeks-2, two weeks to

one month-3, one to two months-4, two to three months-5]