<<

Paediatric Surgery 9 Charlotta Zetterström

| Core Messages 9.1.1 ∑ It is important to detect cataract within Aetiology the first weeks of life ∑ Life-long control is mandatory if operated In the developed world, the cause of most cases on early, high risk for development of of bilateral congenital is idiopathic. About one third are hereditary without sys- ∑ Loss of , important temic disease. These are mostly autosomal to inform before surgery dominant but autosomal recessive and X-linked ∑ IOL implantation is safe and generally traits occur. Rare causes of childhood cataracts accepted over the age of 1 year are metabolic disorders such as ∑ After-cataract is problematic in children and hypocalcemia. Congenital cataracts can be ∑ For lamellar cataract, surgery is often combined with systemic abnormalities such as indicated before school start trisomy 21 and Turner’s syndrome. Mental re- tardation is common in series of bilateral con- genital cataract and there is a multitude of in- herited syndromes with this combination 9.1 associated with other abnormalities such as Introduction craniofacial or skeletal deformities, myopathy, spasticity or other neurological disturbances. Bilateral is the most com- A number of intrauterine infections (toxo- mon cause of treatable . plasmosis, rubella, cytomegalic inclusion dis- Unilateral congenital cataract is an important ease, herpes infection, varicella, and ) cause of and . may cause congenital cataracts. Of these, rubel- in children has changed la is the most important. The rubella cataract is and improved dramatically in recent decades. usually bilateral but may be unilateral. This is mainly a result of modern surgical tech- Ocular conditions such as (Fig. 9.1) niques and improved intraocular lenses. Also, and coloboma (Fig. 9.2) are often seen to- better knowledge of irreversible deprivation gether with cataract. amblyopia and how to treat this has made an Unilateral congenital cataract is,as a rule,not important contribution [13, 33]. associated with systemic disease,is rarely inher- ited and the cause is in the majority of cases idiopathic. About 10% of cases are associated with lenticonus/lentiglobus and persistent foetal vasculature. It may also be masked bilateral cataract because of asymmetric involve- ment. 154 Chapter 9 Paediatric Cataract Surgery

Fig. 9.1. Child with aniridia and complete nuclear Fig. 9.3. New-born child with nuclear cataract dense cataract in the centre

Fig. 9.2. Child with coloboma and cataract Fig. 9.4. Posterior cataract with persistent foetal vas- culature

Summary for the Clinician [18]. The cataract is bilateral in about 80% ∑ In a clinically healthy child with of cases. In cases with bilateral congenital nu- one parent with the disease, and also clear cataract, inheritance can be demonstrated in unilateral cases, an extensive pre- in 30%–50%. The inheritance is in most cases operative investigation to establish autosomal dominant. a cause for the cataract is not necessary Posterior unilateral cataracts in infants and children are in most cases associated with persistent foetal vasculature (PFV) and the 9.1.2 affected is usually small (Fig. 9.4).The retro- Morphology lental vascular structure in contact with the lens capsule may give way to blood vessels encircling Nuclear cataract is usually present at birth and the lens causing haemorrhage, particularly dur- is non-progressive [30]. Dense cataracts present ing surgery (Fig. 9.5). The fibrovascular stalk at birth, where early surgery is mandatory, are may cause tractional . After in most cases of nuclear type (Fig. 9.3). The early surgery, secondary glaucoma is unfortu- opacification is located to the embryonic and nately a common complication in these eyes foetal nuclei between the anterior and posterior [26]. Y sutures and is usually very dense in the centre. Cataract associated with posterior lenti- The eyes are almost always smaller than normal conus or posterior lentiglobus usually develops 9.1 Introduction 155

Fig. 9.5. Posterior persistent foetal vasculature Fig. 9.7. Sutural cataract with little influence on vision

has commonly an autosomal dominant pattern of inheritance. There are some other morphological types of congenital cataracts. Some are due to lenticu- lar developmental defects present at birth. These may have only little influence on vision. Such defects are sutural cataract (Fig. 9.7), and anterior polar cataract, which usually do not progress.

Summary for the Clinician

Fig. 9.6. Lamellar cataract in a 4-year-old child ∑ In the case of nuclear cataract, early surgery is often needed ∑ For lamellar cataract, surgery is often indicated before school start after the critical period of visual development.It is mostly unilateral and occurs sporadically.The change in the lens develops as a small defect in 9.1.3 the posterior lens capsule, which exhibits a pro- Amblyopia and Congenital Cataracts gressive bowing resulting in a posterior bulging and disorganisation of the subcapsular lamellae Amblyopia is caused by abnormal structural and opacification. It is important to be aware of and functional evolution of the lateral genicu- the weakness of the posterior capsule in these late nucleus and striate cortex due to the abnor- eyes during surgery and, if possible, avoid hy- mal visual stimulation during the sensitive peri- drodissection. od of visual development. Lamellar cataract usually develops after es- Reversibility of amblyopia depends on the tablishment of fixation (Fig. 9.6). It is usually stage of maturity of the at which progressive and surgery is often performed be- abnormal visual experience began, the duration fore school age,but the cataract can remain sub- of deprivation and the age at which therapy was clinical for many years. The cataract involves instituted. The most critical period is probably the lamellae surrounding the foetal nucleus pe- between 1 week and 2 months [40]. Disruption ripheral to the Y sutures [30].Eyes with lamellar of vision during this period usually causes se- cataracts are usually of normal size with a nor- vere and permanent visual loss and permanent mal-sized . It is uniformly bilateral and if not managed. If visual deprivation 156 Chapter 9 Paediatric Cataract Surgery

normal maturity of the visual system.Thus,am- blyopia might not be a problem for some chil- dren with partial congenital cataract. If surgery is considered in children with partial cataract it should, if possible, be postponed until the age at which the risk of post-operative complications diminishes. Children with partial cataract treat- ed conservatively must be followed closely. Oc- clusion therapy is necessary in unilateral cases to prevent amblyopia. The clinical evaluation should entail evaluation of visual behaviour in- cluding monocular and binocular fixation pat- Fig. 9.8. Dense congenital cataract terns. Unilateral congenital cataract, dense from birth, causes amblyopia with loss of binocular function and the development of secondary strabismus. In cases of dense bilateral congeni- tal cataract, bilateral amblyopia and nystagmus will occur.

Summary for the Clinician ∑ To prevent irreversible amblyopia in infants with dense cataract from birth, the cataract extraction must be performed early ∑ Children with partial cataract must be followed closely Fig. 9.9. Incomplete congenital cataract

9.2 occurs after the age of 2–3 months, the ambly- Congenital Dense Cataract opia is usually reversible. The sensitivity to am- blyopia gradually decreases until the age of 6 or 9.2.1 7 years when the visual maturation is complete Pre-operative Examination and the retinocortical pathway and the visual centres become immune to abnormal visual in- A careful pre-operative examination of the eyes put [37]. It is thus essential that early treatment is essential, The should first be as- of dense congenital cataract is instituted in or- sessed by direct with the der to avoid irreversible amblyopia [9, 16, 31]. undilated. The cataract is often most dense in Visual loss and the development of ambly- the central part of the lens, after dilatation it opia depend on the size and location of the seems to be less significant. It is important to cataract and particularly on the density. If the examine both eyes and establish whether the opacities are large enough to obscure the fun- cataract is bi- or unilateral. Unilateral congeni- dus view through an undilated pupil, amblyopia tal cataract presents a challenging problem, development can be expected (Fig. 9.8). If reti- since even a mild cataract will cause irreversible nal details such as the larger vessels can be dis- deep amblyopia in one eye if not treated. In tinguished through the central portion of the these children, vision in the affected eye is pre- cataract, conservative treatment can be consid- vented from developing through active suppres- ered (Fig. 9.9). Some infants with partial sub- sion by the non-affected eye [6].While the new- clinical congenital cataract develop sufficient born child is awake it is also important to assess binocular interaction and form vision to allow a visual function, if possible, with a clinical pref- 9.2 Congenital Dense Cataract 157 erential looking grating acuity (Teller acuity card).It is also important to look at the ability to Summary for the Clinician fix and follow and ask the parents if they have ∑ An undilated pupil and no red reflex had any visual interaction with the child. are indications for immediate surgery Children with significant bilateral congenital cataracts may seem to have delayed develop- ment as well as obviously impaired visual be- 9.2.2 haviour. In contrast, children with monocular Surgical Technique in Infants cataracts often present with strabismus, which may not develop until irreparable visual loss has In infants with bilateral cataracts it is advanta- occurred. Since their visual behaviour may be geous to perform surgery in both eyes at the unaffected, children with monocular cataract same surgical intervention.Most of the children are almost always detected much later than cas- are new-born, only a few weeks old, and these es with bilateral cataract.Moreover,in most cas- small children are extremely sensitive with re- es with monocular cataract, they have no family gard to developing amblyopia. Surgery in one history and are otherwise healthy. The presence week on one eye while the other eye remains of manifest nystagmus at the age of 2–3 months with dense cataract can cause irreversible am- or more generally indicates a poor visual prog- blyopia in the non-operated eye. If both eyes are nosis. Complete examinations of infants often operated at the same time sterility must be require sedation or general anaesthesia and can maintained during the whole procedure and often be performed during the same anaesthe- changing all instruments and sterile clothing of sia as the surgery.Both eyes should be examined the surgeon and nurse are advisable between with dilated because malformations in the eyes. the non-cataractous eye are commonly found Axial length and corneal curvature are es- [24]. Anterior segment examination is carried sential measurements for fitting out with measurements of the corneal diameter and IOL power calculation and could advanta- and intraocular pressure (IOP) by Tonopen or geously be performed immediately before sur- handheld Perkins tonometer. The IOP in the gery during the same anaesthesia. Eyes of in- new-born is much lower than in the adult, often fants with congenital cataract are shorter and below 10 mmHg. If the clarity of the media per- have a smaller corneal diameter compared to mits so, indirect ophthalmoscopy may reveal controls. persistent foetal vessels or any other posterior Before surgery the pupil is dilated with a segment abnormalities that may have an impact combination of 1.5% phenylephrine and 0.85% on the visual outcome. Surgery for visually sig- . Rinsing of the with nificant cataract should be carried out as soon chlorhexidine solution 0.05% is performed as possible, preferably within the first weeks of 5 min before surgery. life. If the cataract is unilateral it is even more The surgical intervention should be per- important with early surgery to obtain some formed by a well-trained anterior segment sur- useful visual acuity in the affected eye. A treat- geon to obtain the most advantageous outcome. ment regime based on surgery within 2 months Consequently most of the procedures are done of life, prompt optical correction of the with the anterior approach starting with a scle- and aggressive occlusion therapy with frequent rocorneal tunnel, which ought to be rather long follow-up have been successful in several series to minimise the risk for iris prolapse. High- [5, 7]. If the cataract is incomplete and not inter- viscosity ocular viscosurgical device (OVD) is fering with normal visual development,it is bet- used because the anterior chamber is shallow ter to postpone surgery until the child is older and a high vitreous pressure is found in these with less post-operative complications. In these small eyes. If the pupil is small, which is rather cases it is mandatory with close follow-ups by a common in eyes with congenital cataract, flexi- well-trained paediatric ophthalmologist. ble iris retractors can be very helpful and four of them are placed in the pupil before the continu- 158 Chapter 9 Paediatric Cataract Surgery

ous anterior capsulorhexis is performed. There impossible with the technique used routinely is no reason to open the pupil with the iris re- today. The most important cells concerning af- tractors more than necessary, since a damaged ter-cataract are located at the lens equator and iris will cause more post-operative inflamma- are impossible to see during surgery. When the tion. If the cataract is very dense and grey,stain- capsular bag is empty of all lens material high- ing of the anterior capsule with dye makes the viscosity OVD is injected to fill the capsular bag anterior capsulorhexis much easier and also and a posterior continuous capsulorhexis is safer to perform [32]. The dye can be adminis- performed: slightly smaller than the anterior tered with a blunt syringe under the OVD just rhexis. The posterior capsule is thinner than the above the anterior capsule and painted on the anterior and not so elastic. Sometimes fibrotic capsule with the end of the syringe. In this way parts are found in the posterior capsule which a very small amount of the dye is needed and makes tearing impossible and scissors have to just the capsule and not the whole anterior seg- be used. It is wise to look for persistent foetal ment is dyed. If an (IOL) is im- vasculatures, particularly in unilateral cases planted the anterior capsulorhexis ought to be with posterior cataract. Persistent hyaloid ar- smaller than the optic, round and placed in the tery is adherent to the posterior aspect of the centre. Since the capsule is elastic and thick in lens and the . If present it ought to be the new-born it is important to re-grasp contin- cut with fine scissors; sometimes the vessel con- uously when performing the rhexis. In contrast tains blood, but cautery is seldom indicated. Us- to the adult eye, one ought to aim for a small ing this method it is possible to implant an IOL rhexis to achieve a good size. A complete rhexis in the capsular bag during primary surgery or without any tears is essential in cases when IOL in the ciliary sulcus if a secondary implantation implantation is planned. is scheduled for the future. Capsular fixation is Hydrodissection ought to be carried out with preferred over ciliary sulcus placement because caution and sometimes avoided. In some eyes, such complications such as pupillary capture often with very dense cataract, a defect in the and IOL decentration are more common with posterior capsule, most often formed like an al- ciliary sulcus fixation [29]. mond, could be found. Hydrodissection in these Primary IOL implantation in the new-born cases is of course not recommended because the eye is still debated [22, 39]. In unilateral cases high risk of loosing lens material into the vitre- the amblyopia is more severe, the occlusion ous during the procedure. These cases also have therapy is very hard and the child has an other- opacification with cells in the anterior part of wise healthy eye. Therefore it is easier to accept the vitreous, looking like a fishtail in the anteri- an IOL implantation in theses eyes today, even or vitreous when moving the eye. The posterior though there is no available IOL that really fits capsule is thin and fragile in eyes with posterior the small new-born eye. The bilateral cases are lenticonus and hydrodissection ought to be per- often easier concerning contact-lens wear and formed carefully. treatment of the amblyopia. If an IOL is to be It is almost always possible to remove the nu- implanted it ought to be in the bag with com- cleus and cortex with irrigation and aspiration. plete anterior and posterior capsulorhexes. A However, sometimes in very dense nuclear foldable one-piece hydrophobic IOL could be cataracts, and with white calcified parts in the implanted with an injector through a 2.75-mm nucleus, ultrasound has to be used. The new incision also in this age group. With high-vis- technique AquaLase liquefaction, which uses a cosity OVD remaining in the anterior chamber warm-water stream, may prove very useful and the IOL implanted in the bag, a dry anterior when removing these dense cataracts. It is im- vitrectomy could safely be performed through portant to remove all lens material to minimise the pupil and the two capsulorhexes. The OVD post-operative inflammation, which is very pro- ought to be removed to avoid elevated IOP after nounced in young patients. To reduce opacifica- surgery. The pupil is closed with acetylcholine tion of the visual axis removal of most lens ep- (Miochol), and it is wise to ensure that no vitre- ithelial cells is important; however, it is almost ous is present in the anterior part of the eye.The 9.3 Cataracts in Older Children 159 is soft and elastic in children and it is hard to achieve a self-sealing incision in most Summary for the Clinician cases. Thus the incision should be closed with a ∑ Surgery ought to be centralised running or horizontal 10–0 nylon suture. Ante- ∑ No patching after surgery rior formation to the wound is rather ∑ Prophylactic antibiotic treatment should often seen in the youngest. It is important at the take the following forms: end of the procedure to look for this and to have – Rinsing of conjunctiva with 0.05% a stable and good anterior chamber. Iridectomy chlorhexidine solution or 5% is not necessary in these eyes; this is true also if povidone iodine before surgery the eye is left aphakic. However, the lens capsule – 0.5–1.0 mg cefuroxime intracameral has to remain in the eye, otherwise it is wise to at the end of surgery perform an iridectomy to avoid intra-ocular pressure spikes. is one of the most serious 9.3 complications after intraocular surgery and Cataracts in Older Children prophylactic antibiotics are recommended. Pe- rioperatively, at the end of surgery, injection of 9.3.1 1 mg of cefuroxime (Zinacef) in 0.1 ml saline Pre-operative Examination 0.9% into the anterior chamber is an effective and safe method [27, 28] to avoid infection. In If the cataract was incomplete at birth close fol- the new-born eye 0.5 mg of cefuroxime seems to low-up by a paediatric ophthalmologist is ad- be sufficient. This regime effectively prevents vised.Visual acuity ought to be followed, if pos- gram-positive bacteria species which is by sible, with clinical preferential looking grating far the most common bacteria. Prophylactic acuity (Teller acuity card).It is also important to vancomycin in the irrigating solution during look at the ability to fix and follow and ask the cataract surgery is not routinely recommended parents if they have visual interaction with the by the authors because of possible increased in- child. Examination of strabismus and binocular cidence of cystoid macular oedema [4] and the functions are also important. In older children risk of emerging resistance to the antibiotic. visual acuity could be measured with greater re- The anti-inflammatory treatment should start liability. Above the age of 4 years most children early after surgery and a perioperative subcon- could be examined with letters and monocular- junctival injection of 2 mg of steroids (Be- ly. In children not only the visual acuity has to tapred) is recommended at the end of the surgi- be considered but also the development of am- cal procedure. We have not used protective blyopia. If a child has unilateral cataract or a patches for any children after surgery for many more dense cataract in one eye, occlusion thera- years and have not seen any disadvantages with py has to be considered. Most of the children this regime. On the contrary, the child starts the with congenital cataract have small eyes and hy- amblyopia treatment immediately and the par- peropic should be prescribed if needed. ents are very pleased when they are able to es- Nowadays,surgery in children has almost the tablish visual interaction with the child for the same indications as in grown-ups with one im- first time soon after surgery. portant exception, if the cataract is too dense, children below the age of 7 will develop ambly- opia, which means it is not advisable to post- pone the surgery. 160 Chapter 9 Paediatric Cataract Surgery

In older children, both eyes could be operat- one ought to consider a damaged posterior cap- ed during the same surgical intervention or in sule. While the posterior capsule is much thin- two sessions, while the development of ambly- ner and more fragile than the anterior one it opia is not as quick as in the youngest. To wait could also break without perforation of the 1–2 months between the eyes is in most cases ac- . ceptable. The child and the parents have to be In cases with an incomplete anterior capsu- informed before the intervention that accom- lorhexis as after trauma, and a broken anterior modation is going to be lost after surgery and or posterior capsule, optic capture could be a spectacles, often bifocal, are needed. good option to avoid late decentration of the IOL [10]. The optic is then pushed behind the Summary for the Clinician posterior capsulorhexis, the haptics remaining ∑ Amblyopia can be avoided by performing in the bag. The capsulorhexis has to be in the surgery centre and smaller than the optic, otherwise the ∑ After surgery loss of accommodation is IOL optic will escape from the capture. In these found and glasses are needed cases the lens epithelial cells may grow on the IOL surface forming after-cataract [36]. If per- forming optic capture in the posterior or anteri- 9.3.2 or rhexis is considered,a three-piece IOL should Surgical Technique be chosen rather than a one-piece design. The one-piece acrylic IOL cannot be pushed behind The surgical technique used in children above the capsulorhexis since the haptics and optic the age of 1 year does not differ greatly from the have to be in the same plane. Also, most of the technique used in the infant eye. The incision three-piece lenses are posteriorly angulated and can be sclerocorneal or clear corneal and 12 o’- therefore suitable for this technique. clock or temporally if preferred. IOL implantation within the capsular bag is Summary for the Clinician important to decrease after-cataract formation ∑ Anterior and posterior capsulorhexis [42] and inflammation. Posterior capsulorhexis in all children is regularly performed until at least the age of ∑ Anterior dry vitrectomy in younger 15 years otherwise after-cataract will develop children below the age of 7 years within a short time. Anterior dry vitrectomy ∑ IOL implantation is safe, including bilater- ought to be performed at the primary surgery in ally, in children over the age of 1 year pre-school children to avoid early after-cataract formation [15, 17, 35]. The authors prefer to per- form the vitrectomy through the limbal inci- 9.4 sion,but others advocate a approach. IOL Power and Model With the pars plana approach, separate irriga- tion is provided anteriorly through a limbal These days it is perfectly safe and acceptable to paracentesis incision. do a primary implant from the age of 1 year, In children with cataract after trauma both even when both eyes are operated on [11, 41]. the anterior and posterior capsule could be Primary implants in younger children is still damaged. In cases with relatively immediate controversial. In the unilateral cases operated cataract development after a corneal wound the on early, i.e. at only a few weeks of age, a possi- anterior capsule is often broken. The condition ble option is a primary implant. It has been of the posterior capsule is unknown in most found that an implant in the capsular bag would cases, and it is important to avoid hydrodissec- decrease the total amount of proliferating lens tion,or performing it very carefully to avoid los- epithelial cells [42]. The formation of after- ing lens material into the vitreous. In some cas- cataract is particularly problematic in the es with blunt trauma, no perforation of the youngest patients. globe and rapid development of dense cataract 9.4 IOL Power and Model 161

At least in the unilateral cases, implantation This is also a very soft IOL and therefore proba- of an IOL could be an improvement in the treat- bly suitable for the small eyes of the new-born ment of aphakia, amblyopia, after-cataract and baby when implanted in the capsular bag [20]. maybe also secondary glaucoma. In this age Problems such as breakage of the haptics and group the deprivation amblyopia is by far the retarded ocular growth have been encountered greatest problem. Aiming for at with earlier generation IOLs implanted in the surgery is therefore most appropriate in this age monkey and rabbit eye [19, 21]. The single-piece group. Sometimes the desired IOL power is not AcrySof is not recommended for sulcus fixa- available because of high hyperopia, in these tion. Unlike the three-piece design, the haptics cases a supplement of a contact lens for some are thick and are not posteriorly angulated. time could be an option. The refraction will Years after surgery decentration and iris chafing change considerably during the subsequent can occur. An IOL containing a filter removing years and the eye will become highly myopic but the harmful blue light is most probably advan- hopefully not highly amblyopic. Corneal refrac- tageous for the maculae in these eyes,which will tive surgery, piggyback implantation or im- have implants for many years. planted contact lenses are all different options Multifocal IOLs should not be considered in in the future for correction of the . young children with a growing eye. The axial In bilateral cases the best solution is proba- length increases during life from a mean of ap- bly aiming for emmetropia when the child be- proximately 16.8 mm at birth to 23.6 mm in the comes an adult.Depending on the age at surgery adult with a very rapid growth during the first the amount of hyperopia will differ. It is impor- 18 months. The mean refractive power of the tant to inform the child and parents before the cornea decreases from about 51 at surgery that the child will probably need bifocal birth to 45 dioptres at 6 months of age and to glasses for the rest of his or her life. 43.5 dioptres in adults. Consequently, the refrac- Accurate axial length and corneal curvature tion will change dramatically during childhood. measurements before surgery are necessary for IOL power calculation. In small children this Summary for the Clinician could be performed during the same anaesthe- ∑ In unilateral cases aim for emmetropia sia as the surgery and in older children it could at surgery be performed before the surgery.Eyes with con- ∑ In bilateral cases aim for emmetropia genital cataract are often shorter than normal in adulthood eyes and most of the children do need higher IOL power than the average child of the same age. 9.4.1 The inflammatory reaction is more pro- Post-operative Treatment nounced in children and it is very important to use an IOL with high biocompatibility and ac- Post-operatively, the eye of a child will tend to curate clinical documentation. react with much more inflammation than the Capsular bag growth does not continue after adult eye,particularly in darkly pigmented eyes. lensectomy, which is important when selecting Systemic treatment with glucocorticoids is lens implants [38]. most often not indicated, an exception to this A foldable acrylic lens with a sharp edge and rule being children with . It is however an optic diameter of 6 mm is advantageous in important to start the topical treatment with decreasing or delaying after-cataract formation dexamethasone 0.1% or another potent topical in the visual axis and minimising the incision immediately after surgery. The size [12], which is advantageous because a drops are tapered over 1 month starting with smaller incision results in less post-operative four to five times per day in the elderly. In the inflammation [23]. By using a single-piece new-born the treatment has to be more intense acrylic IOL and the Monarch injector, the inci- starting with eight to ten times daily and ta- sion size could be minimised to 2.75 mm [34]. pered over 2–3 months.In the youngest eyes and 162 Chapter 9 Paediatric Cataract Surgery

in eyes with dark brown irides, mydriatic drops cases occlusion therapy is sometimes useful if (tropicamide or cyclopentolate) are adminis- one eye is more amblyopic than the other eye. tered for several weeks after surgery. Following The occlusion therapy in cases with bilateral this treatment regime, synechia formation cataract usually do not need to be as aggressive could more easily be avoided and as in the unilateral cases. would be easier to perform before glasses are Close follow-up by a paediatric ophthalmol- prescribed. ogist is mandatory until the patient is 7 years of Immediate correction of the aphakia is age, while untreated amblyopia is soon irre- mandatory for the best possible visual outcome. versible. When surgery is performed during the There are different options and these days most first months of life, life-long follow-up is essen- of the children are implanted with an IOL dur- tial because of the high risk of developing sec- ing primary surgery. Some new-borns are im- ondary glaucoma. planted with an IOL; however, in most cases the IOL is not strong enough, leaving some uncor- Summary for the Clinician rected hyperopia in the beginning. In theses ∑ Intense topical treatment with a strong cases a contact lens is the best option, giving the topical corticosteroid, e.g. dexamethasone, opportunity to change the strength over time. particularly in infants below age 2 years, If no IOL is implanted contact lenses are best is recommended fitted already in the operating theatre for imme- ∑ Mydriatic drops in very young patients diate optical correction,to prevent otherwise ir- reversible deprivation amblyopia. Several types of lenses are available. Rigid gas permeable 9.4.2 lenses have a wide range of available strengths Post-operative Complications and have a great ability to correct large astig- matic errors. They are easy to insert and re- 9.4.2.1 move, but cause more foreign body sensation After-Cataract than soft lenses. The two major soft lenses are silicone and soft hydrogel lenses. Both are suit- Opacification of the visual axis is the most com- able but soft hydrogel lenses are less expensive mon complication found after cataract surgery, which is an important consideration due to fre- particularly in the youngest.Even when a poste- quent lens loss. Loss of lenses and fast eye rior capsulorhexis has been performed, growth growth during infancy necessitate frequent lens of lens epithelial cells on the vitreous surface or replacements, especially during the first 2 years on the back of the optic can be found some of life. Frequent retinoscopy must be performed months after surgery (Fig. 9.10). Performing to decide the power of the lens. Most authorities posterior capsulorhexis and dry anterior vitrec- recommend an overcorrection of +2.0 to +3.0 D tomy seems to be one way to decrease opacifica- until bifocals can be tolerated, which occurs be- tween the age of 2 and 3 years. The child should be provided with aphakic spectacles as an op- tion if contact lenses are unsuitable. In older children implanted with an IOL, bifocal glasses are prescribed after retinoscopy and the remaining hyperopia is corrected. This is often done at 1 month after surgery at the latest. Occlusion therapy is started in unilateral cas- es as soon as the media is clear and the aphakia is corrected,and the therapy needs to be aggres- sive. Virtually all children with unilateral con- genital cataract develop strabismus. In bilateral Fig. 9.10. After-cataract 2 years after surgery 9.4 IOL Power and Model 163

Fig. 9.11. Decentration of the posterior capsu- Fig. 9.12. Shrinkage of the capsule with phimosis of lorhexis the rhexis

tion in the post-operative time [17]. In the very phimosis (Fig. 9.12) of the capsulorhexis could young patients, implanted during their first make a secondary intervention necessary. Cap- weeks of life,surgical intervention could be nec- sule contraction is more often found in eyes im- essary several times, while the lens epithelial planted with a silicone IOL [8]. cells are growing over and over again on the back of the optic. An IOL implanted in the bag 9.4.2.2 will decrease or prevent formation of Soemmer- Secondary Glaucoma ing’s ring and the epithelial cells can easier mi- grate from the periphery to the centre of the Secondary glaucoma is unfortunately a com- pupil. If opacification occurs in the pupil mon complication and by far the most sight- Nd:YAG laser treatment could be tried; howev- threatening [2, 25]. The highest incidence is er, this is often inadequate in children since ref- found when the surgery has been done early, ormation of the opacification can be found that is below the age of 2 months, and a much some months later in these highly reactive eyes. lower incidence is found when surgery has been Surgical intervention is often necessary under performed over the age of 1 year [25]. Eyes with general anaesthesia and has to be performed small corneal size, nuclear cataract and persist- promptly to avoid amblyopia. Through a small ent foetal vasculature are at greatest risk [30]. limbal incision high-viscosity OVD is injected Implantation of an IOL into the capsular bag into the anterior chamber to keep it stable dur- seems to inhibit the development of secondary ing the procedure. An incision in the pars plana glaucoma [3]. and a sharp thin knife is inserted behind the iris In the new-born eye a rise in the intraocular and IOL and the membrane is divided.With dry pressure will cause epithelial oedema of the anterior vitrectomy the lens epithelial cells cornea, a poor red reflex, and fast growing in the pupil and also the anterior part regression of hyperopia or growing eye. These of vitreous are removed. At the end of the sur- children must be examined promptly under gery the pars plana incision is closed with a run- general anaesthesia. Corneal oedema in chil- ning suture and the OVD is removed from the dren wearing contact lenses could be due to hy- anterior chamber to avoid a pressure peak post- poxia, and the contact lens must be removed operatively. immediately. The anaesthesia of choice is keta- After the procedure, topical dexamethasone mine hydrochloride since it does not lower the is needed for some weeks. Problems with the IOP which most of the other anaesthetics do. lens capsule after surgery, such as decentration During the evaluation under anaesthesia, IOP, (Fig. 9.11) of the anterior or posterior capsu- corneal diameter,and axial length are measured lorhexis or shrinkage of the capsular bag with and examination of the optic disc and retino- 164 Chapter 9 Paediatric Cataract Surgery

scopy are performed. Acute glaucoma may de- velop in cases with excessive inflammation Summary for the Clinician leading to pupillary block and iris bombé.A pe- ∑ Good red reflex is essential for favourable ripheral iridectomy and an anterior vitrectomy development of vision are often sufficient to solve the problem. Later ∑ Rapid growth of the eye should arouse on, a more chronic type of glaucoma could de- suspicion of secondary glaucoma velop probably due to the heavy inflammatory ∑ Life-long follow-up in cases with surgery response after surgery leading to synechia for- within the first months of life because of mation in the chamber angle and a slow rise secondary glaucoma in IOP over time [14]. Some of the eyes with secondary glaucoma could be controlled with topical medication but many will need a tra- 9.5 beculectomy with mitomycin C. In some cases Current Clinical Recommendations also a glaucoma shunt is required for pressure control. Summarising the previously given information, It is important to remember that when the following recommendations can be made: cataract surgery has been performed during the – Prompt surgery is performed in cases with first months of life the IOP and have dense congenital cataract – if nystagmus has to be controlled life-long [1]. developed, the amblyopia is irreversible – Post-operative complications such as high 9.4.2.3 rate of after-cataract and secondary glauco- Fibrinoid Reaction ma are matters of concern in the new-born and life-long follow-up is essential in these Because of the high degree of inflammation in cases children, fibrin in the pupil can be found even – Occlusion therapy ought to be initiated if when an IOL with high biocompatibility has amblyopia is present in one eye been implanted. Frequently administered topi- – IOL implantation could safely be performed cal steroids and mydriatics are helpful in these above the age of one year cases. In a few cases Nd:YAG laser treatment – Anterior dry vitrectomy ought to be per- could be indicated to clear the visual axis.Poste- formed in pre-school children to avoid after- rior synechiae formation in the post-operative cataract period is common, especially in the new-born when no IOL has been implanted. References 9.4.2.4 Decentration of the Pupil 1. Asrani SG, Wilensky JT (1995) Glaucoma after congenital cataract surgery. Incarceration of the iris in the wound is some- 102:863–867 2. Asrani SG, Wilensky JT (1995) Glaucoma after times encountered. To avoid this complication a congenital cataract surgery. Ophthalmology rather long tunnel is recommended during 102:863–867 cataract extraction and suture ought to be used 3. Asrani, S, Freedman S, Hasselblad V,Buckley EG, to close the wound. Careful surgery is also help- Egbert J, Dahan E, Gimbel H, Johnson D, Mc- ful leaving the iris without trauma and atrophy. Clatchey S, Parks M, Plager D, Maselli E (2000) If the visual axis is covered with iris it is impor- Does primary intraouclar lens implantation pre- tant to promptly reposition the iris or make a vent “aphakic” glaucoma in children? J AAPOS 4:33–39 new central pupil with surgical intervention or 4. Axer-Siegel R, Stiebel-Kalish H, Rosenblatt I, Nd:YAG laser treatment. Strassman E, Yassur Y, Weinberger D (1999) Cystoid after cataract surgery with intraocular vancomycin. Ophthalmology 106:1660–1664 References 165

5. Birch EE, Swanson WH, Stager DR, Woddy M, 19. Kugelberg U, Zetterström C, Lundgren B, Syrén- Everett M (1993) Outcome after very early treat- Nordqvist S (1996) Eye growth in the aphakic ment of dense congenital unilateral cataract. In- newborn rabbit. J Cataract Refract Surg 22: vest Ophthalmol Vis Sci 34:3687–3699 337–341 6. Birch EE,Stager D,Leffler J,Weakley D (1998) Ear- 20. Kugelberg M, Shafiei K, Zetterström C (2004) ly treatment of congenital unilateral cataract One-piece AcrySof in the newborn rabbit eye. J minimizes unequal competition. Invest Ophthal- Cataract Refract Surg, in press mol Vis Sci 39:1560–1566 21. Lambert SR, Fernandes A, Grossniklaus HE 7. Cheng KP, Hiles DA, Biglan AW, Pettapiece MC (1995) Haptic breakage following neonatal IOL (1991) Visual results after early surgical treatment implantation in a non-human primate model. J of unilateral congenital cataracts. Ophthalmolo- Pediatr Ophthalmol Strabismus 32:219–224 gy 98:903–910 22. Lambert SR, Buckley EG, Plager DA, Medow NB, 8. Cochener B, Jacq PL, Colin J (1999) Capsule con- Wilson ME (1999) Unilateral intraocular lens im- traction after continuous curvilinear capsu- plantation during the first six months of life. J lorhexis: Poly (methylmethacrylate) versus sili- AAPOS 3:344–349 cone intraocular lenses. J Cataract Refract Surg 23. Laurell CG, Zetterström C, Lundgren B, Torngren 25:1362–1369 L, Andersson K (1997) Inflammatory response in 9. Dutton JJ, Baker JD, Hiles DA et al (1990) View- the rabbit after phacoemulsification and intraoc- points: visual rehabilitation in aphakic children. ular lens implantation using a 5.2 or 11.0 mm inci- Surv Ophthalmol 34:365–384 sion. J Cataract Refract Surg 23:126–131 10. Gimbel HV (1997) Posterior continuous curvilin- 24. Lewis TL, Maurer D, Tytla ME, Bowering ER, ear capsulorhexis and optic capture of the in- Brent HP (1992) Vision in the “good” eye of chil- traocular lens to prevent secondary opacification dren for unilateral congenital cataract. Ophthal- in pediatric cataract surgery. J Cataract Refract mology 99:1013–1017 Surg 23:652–656 25. Lundvall A, Zetterström C (1999) Complications 11. Gimbel HV, Basti S, Ferensowicz M, DeBroff BM after early surgery for congenital cataracts. Acta (1997) Results of bilateral cataract extraction with Ophthalmol Scand 77:677–680 posterior chamber intraocular lens implantation 26. Lundvall A, Kugelberg U (2002) Outcome after in children. Ophthalmology 104:1737–1743 treatment of congenital unilateral cataract. Acta 12. Hollick EJ, Spalton DJ, Ursell PG, Pande MV Ophthalmol Scand 80:588–592 (1998) Lens epithelial cell regression on the pos- 27. Montan PG, Wejde G, Setterquist H, Rylander M, terior capsule with different intraocular lens ma- Setterström C (2002) Prophylactic intracameral terials. Br J Ophthalmol 82:1182–1188 cefuroxime. Evaluation of safety and kinetics in 13. Jacobson SG, Mohindra, Held R (1981) Develop- cataract surgery. J Cataract Refract Surg 28:982– ment of visual acuity in infants with congenital 987 cataracts. Br J Ophthalmol 65: 727–735 28. Montan PG, Wejde G, Koranyi G, Rylander M 14. Keech RV,Tongue AC, Scott WE (1989) Complica- (2002) Prophylactic intracameral cefuroxime. tions after surgery for congenital and infantile Efficacy in preventing endophthalmitis after cataracts. Am J Ophthalmol 108: 136–141 cataract surgery. J Cataract Refract Surg 28:977– 15. Koch DD, Kohnen T (1997) Retrospective com- 981 parison of techniques to prevent secondary 29. Pandey SK, Wilson ME, Trivedi RH, Izak AM, cataract formation after posterior chamber in- Macky TA, Werner L, Apple DJ (2001) Pediatric traocular lens implantation in infants and chil- cataract surgery and intraocular lens implanta- dren. J Cataract Refract Surg 23: 657–663 tion: current techniques, complications, and 16. Kugelberg U (1992) Visual acuity following treat- management. Int Ophthalmol Clin 41:175–196 ment of bilateral congenital cataracts. Doc Oph- 30. Parks MM, Johnson DA, Reed GW (1993) Long- thalmol 82: 211–215 term visual results and complications in children 17. Kugelberg M, Zetterström C (2002) Pediatric with aphakia. A function of cataract type. Oph- cataract surgery with or without anterior vitrec- thalmology 100:826–841 tomy. J Cataract Refract Surg 28: 1770–1773 31. Rogers GL, Tishler CL, Tsou BH, Hertle RW, Fel- 18. Kugelberg U, Zetterström C, Syren-Nordqvist S lows RR (1981) Visual acuity in infants with con- (1996) Ocular axial length in children with unilat- genital cataracts operated on prior to 6 months of eral congenital cataract. Acta Ophthalmol Scand age. Arch Ophthalmol 99:999–1003 74: 220–223 166 Chapter 9 Paediatric Cataract Surgery

32. Saini JS, Jain AK, Sukhija J, Gupta P, Saroha V 38. Wilson ME, Apple PJ, Bluestein EC, Wang XH (2003) Anterior and posterior capsulorhexis in (1994) Intraocular lenses for pediatric implanta- pediatric cataract surgery with or without trypan tion: biomaterials, designs, and sizing. J Cataract blue dye: randomized prospective clinical study. Refract Surg 20:584–591 J Cataract Refr Surg 29:1733–1737 39. Wilson ME, Peterseim MW, Englert JA, Lall-Trail 33. Taylor D, Vaegan X, Morris JA, Rodgers JE, War- JK, Elliot LA (2001) Pseudophakia and poly- land J (1979) Amblyopia in bilateral infantile and pseudophakia in the first year of life. J AAPOS juvenile cataract. Relationship to timing of treat- 5:238–245 ment. Trans Ophthalmol Soc UK 99:170–175 40. Wright K (1995) Visual development, amblyopia, 34. Trivedi RH, Wilson EM (2003) Single-piece and sensory adaptations. In: Wright KW (ed) Pe- acrylic intraocular lens implantation in children diatric ophthalmology and strabismus. Mosby 29:1738–1743 Year Book, St Louis 35. Vasavada A, Desai J (1997) Primary posterior cap- 41. Zetterström C, Kugelberg U, Oskarsson C (1994) sulorhexis with and without anterior vitrectomy Cataract surgery in children with capsulorhexis in congenital cataracts. J Cataract Refract Surg of anterior and posterior capsules and heparin- 23:645–651 surface-modified intraocular lenses. J Cataract 36. Vasavada AR, Trivedi RH, Singh R (2001) Necessi- Refract Surg 20:599–601 ty of vitrectomy when optic capture is performed 42. Zetterström C, Kugelberg U, Lundgren B, Syrén- in children older than 5 years. J Cataract Refract Nordqvist S (1996) After-cataract formation in Surg 27:1185–1193 newborn rabbits implanted with intraocular 37. von Noorden G (1978) Klinische Aspekte der lenses. J Cataract Refract Surg 22:85–88 Deprivationsamblyopie.Klin Mbl Augenheilk 173: 464–469