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222 November 2002 Category 1

222 November 2002 Category 1

Rhegmatog PAMELA DALY, CST, SA-C genousRETINAL o DETACHMENTS he is comprised of in the area of detachment.16,22,2

1.2 million photorecep- The incidence of primary reti- tors that are responsible nal detachment is approximately

for changing light rays 12 cases per 100,000.11 They occur T into electrical impulses more often in men, typically that are carried along the optic between ages 40 and 70.17

nerve to the brain.22 The retina This article will describe the must remain firmly adhered to pathogenesis and treatment of the retinal pigment epithelium primary rhegmatogenous retinal

(RPE) on the inside wall of the eye detachment (RRD), an uncommon in order to function properly. In yet important cause of visual loss a , the retina that can be treated most effec-

separates from the RPE, causing tively by early recognition of malfunction of the photorecep- symptoms and urgent surgical tors and diminished vision correction.

NOVEMBER 2002 The Surgical Technologist 9 222 NOVEMBER 2002 CATEGORY 1

Anatomy for the posterior portion of the vitreous. The The posterior eye wall is formed by three juxta- posterior hyaloid collapses inward toward the posed layers: (1) the , which is a tough, central vitreous cavity, peeling itself off of the fibrous outer shell that serves to protect the retina. The more liquefied vitreous fluid leaks internal ocular structures; (2) the , a into the space created by the collapse of this pos- highly vascular layer that provides nutrients to terior gel. This process is called a posterior vitre- the outer portion of the retina, (along with the ous detachment (PVD).1,2,3,6,7,10,16 PVDs occur in RPE); and (3) the retina which contains the pho- virtually all adults and the incidence increases toreceptors, neurosensory fibers and support- with age.4 , , pseudophakia, ing cells that transmit visual information to the inflammation and trauma can also increase the brain.21,22 (Figure 1) likelihood of PVD.7 Roughly 75% of all 75-year- The posterior segment of the eye receives light old patients show evidence of PVD on a dilated that passes through the anterior segment struc- eye examination.17 tures (the , and ) and converges PVDs are usually asymptomatic, but patients that light on the retinal surface.21 (Figure 2) The may notice an abrupt increase in visual abnor- acentral part of the retina, the macula, is the part malities (usually in the form of new floaters or of the retina that is aligned with the central visu- peripheral flashes of light).6,8 Floaters occur for al axis; when it is diseased, central acuity is poor several reasons. The liquefied vitreous is now while peripheral vision is often spared. The vitre- much more mobile because it has detached itself ous cavity is the central portion of the , and from the retinal surface. The differences in the is filled with a clear, collagenous gel, called the viscosity of the more formed and less formed . As the eye ages, the relationship portions of the gel can cause visual aberrations.23 between the vitreous gel and the peripheral reti- As the gel detaches from the retina it can also pull na forms the basis for understanding the patho- fibrous, glial tissue off the head (a genesis of rhegmatogenous retinal detach- Weiss ring) that can be seen as a circular floater ments.1,2,5,7 in the central portion of vision.22 Hemorrhage can also cause new floaters. This Pathogenesis and classification typically occurs when the retina becomes torn Primary RRD are formed when a retinal tear or during a PVD.2 As the gel peels away from the break occurs, allowing the vitreous fluid to seep retina, any area of abnormally strong vitreoreti- through the retinal break and gain access to the nal adhesion (prior trauma, scars, lattice degen- subretinal space.4 This process occurs as a com- eration or other retinal disease) may place the plication of a natural maturing of the vitreous patient at risk for a retinal tear.3,13,22 The gel will gel.2 In a younger person, the vitreous gel has a either break free (with no retinal damage) or will high concentration of collagen and relatively low remain stuck. A flap of retina will be pulled water content. This makeup creates a vitreous toward the central part of the eye along with the body that is well formed, with the consistency of vitreous body, creating a tear. Patients with gelatin. evolving PVD often experience peripheral With age, the collagen content naturally flashes caused by the traction and tugging on diminishes and the water content increases, the retina by the vitreous.1,2,4,16 The resulting yielding vitreous that has the consistency of an horseshoe tear usually progresses to a primary egg white. As the vitreous breaks down and RRD—primary, since no other disease led to the becomes much more fluid, the collagenous por- detachment, and rhegmatogenous, since a reti- tion is still attached to the retinal surface as a nal break led to the accumulation of subretinal broad sheet. This is called the posterior hyaloid fluid (rhegma=break).23 or posterior vitreous face. The liquefaction of the Once fluid begins to enter the subretinal central vitreous cavity causes a loss of support space and elevate the retina off of the ,

The Surgical Technologist NOVEMBER 2002 10 FIGURE 1

Extraocular muscle Anatomy

Retina of the eye. Conjuctiva Sclera Choroid Schlemm’s canal Retinal blood vessels Anterior chamber Macula

Cornea

Iris

Crystalline lens

Anterior chamber angle

Posterior chamber

Zonules Central retinal Optic nerve blood vessels

visual field anomalies can be seen in the area detachment usually can preserve sharp 20/20 of detachment due to lack of nutrition of the acuity (with correction).23 photoreceptors.1,22 At this stage, patients may Other forms of retinal detachment include still have crisp central vision but a slowly exudative and tractional. Exudative detachments enlarging field deficit. If repair is not per- occur as a result of extreme inflammation, formed at this stage, the visual darkening will abnormal blood vessel growth beneath the retina progress across the eye, through the central (choroidal neovascular membranes), or cancer- part of vision. When this occurs, the vision ous conditions (lymphoma, melanoma).22 The usually drops to the “finger-counting” to fluid that collects in the subretinal space does not “hand-motions” level. Prompt surgical inter- come from the vitreous cavity as in primary vention once the macula has detached will usu- rhegmatogenous detachments, but instead is ally restore a significant amount of central acu- proteinasceous serous fluid that leaks from ity, but, in most cases, the best-corrected vision abnormally permeable blood vessels.15,22 improves postoperatively only to the 20/50 Tractional detachments occur as a result of level.23 Prompt correction prior to macular scar tissue that grows across the concave retinal

NOVEMBER 2002 The Surgical Technologist 11 FIGURE 2 Sclera

Light rays converge Iris Film on to the retina like Lens the film of a camera. Ifthe film or retina is Lens Cornea not good,the image Retina won’t be clear. Vitreous Optic nerve

surface and then contracts, shortening the reti- placed cautery 2-3 mm into the wound. Using na and elevating it off of the concave eye wall. this technique, he achieved a 40-50% reattach- Proliferative diabetic and prolifera- ment rate.23 tive vitreoretinopathy are two examples of severe Others quickly improved upon Gonin’s orig- traction-producing diseases.12,15,22,23 inal operation. Gonin espoused two main prin- ciples that remain the basis for all successful reti- History of surgical correction nal detachment surgery: (1) all breaks must be Hermann Von Helmholtz is credited with found, and (2) all breaks must be accurately inventing the ophthalmoscope in 1851; this localized (so they can be closed).22 Gonin recog- advance created the means to accurately describe nized that a surgical failure meant that the retinal and subsequently repair retinal detachments.17,23 break was not properly closed or that another Jules Gonin is considered to be the father of reti- break existed.22,23 nal detachment surgery. He believed, along with Two significant advances in fundus examina- Theodor Leber, that liquid vitreous forced holes tion were made in the late 1940s. Charles Schep- in the retina. Leber found retinal breaks in 70% ens’ electrically illuminated binocular indirect of all retinal detachments and noted that there ophthalmoscope remains the most valuable was usually a break in the area where the retinal instrument currently available for evaluation of detachment began.17,23 Both Gonin and Leber a detached retina. The Goldman three-mirror stressed that contraction of the vitreous body lens permits stereoscopic examination tore holes in the retina at sites of previous chori- of almost the entire retina if the pupil can be oretinitis (inflammation) or by chorioretinal widely dilated and if the ocular media (cornea, degeneration. lens, vitreous) is clear.22 In 1938, Bengt Rosen- Once Gonin realized that retinal breaks led to gren increased the rate of reattachment by detachment, he concluded that a permanent injecting air into the vitreous to tamponade the cure depended on sealing them. In 1919, he per- retinal break after diathermy treatment and formed the first operation designed to close reti- drainage of subretinal fluid.With this technique, nal breaks.17 After localization of the break, he Rosengren’s reattachment rate improved to made a radial incision through the sclera to the 76%.23 choroids with a Graefe knife, then used the knife In 1953, Ernst Custodis introduced scleral to incise the choroids and enter the subretinal indentation, or “buckling,”to help close retinal space, draining the subretinal fluid. He then breaks. He called the procedure plombenauf-

The Surgical Technologist NOVEMBER 2002 12 nahung, literally,“the sewing on of a seal.”He Originally, he buried polyethylene tubing at the first treated all breaks with surface diathermy posterior end of the most posterior break and and then closed all breaks with a polyviol explant drained subretinal fluid.The implant was intend- (the “plombe”) sutured to the sclera overlying ed to act as a postoperative “dyke” of sorts, pre- the retinal breaks.22,23 The indenting explant venting posterior leakage of subretinal fluid from reduced vitreous traction on the retina and any open anterior break. He later used implants closed the break, allowing a firm chorioretinal made of silicone to completely close all retinal scar to form.22,23 Custodis emphasized that the breaks.22 Schepens also is credited with empha- explant must be large enough to close the entire sizing the importance of encircling the eye with break, as he found that a misplaced explant the buckling element to permanently reduce vit- could inhibit proper break closure. His success reous traction on the peripheral retina.17,22,23 rate improved to 84%.20 Schepens pioneered the use of implants in the Surgical procedure for RRD scleral bed to reduce vitreous traction and to pre- A patient who has been diagnosed with an RRD vent posterior progression of the detachment. is given an explanation of the risks involved with FIGURE 3 Cryoplexy of retinal break. Cryo probe Retinal detachment

Retinal break

Macula

Retinal vasculature

NOVEMBER 2002 The Surgical Technologist 13 FIGURE 4 A After the eye has been prepped, usually with a Betadine solution and water, the surgical tech- Scleral buckling for nologist can then drape the eye with a non-fen- estrated eye drape. After an opening has been treatment of retinal made into the drape with a scissors, usually a Westcott scissors, a lid speculum is inserted into

detachment. ax 800-730-2215. the eye so it remains open during the operation. It is typical for the surgeon to relax the conjunc- Preparation of tiva and perform a periotomy around the lim- bus. At this point, a Curtis-Stevens tenotomy sclera for buckle scissors can be used to clear the from the sclera. Scleral buckle A method for securing the buckle around the globe of the eye utilizes the four rectus muscles. sutured in place. One way of isolating the muscles is with the use of a muscle hook. The hook is placed under the B muscle and then wiped clean with a sterile swab. A cannulated muscle hook loaded with a tying suture can then be placed under the muscle, and the suture pulled through and tied loosely. Typi- cally, the surgeon inspects the detachment with 1st edition by AST (c)2001.Reprinted1st edition by Learnin:www.thompsonrights.com.FThompson with permission of Delmar Learning,a division of the indirect ophthalmoscope and marks the area of detachment on the sclera with the use of a Connor depressor and a marking pen. It is com- mon, at this point, to freeze the area of detach- ment with the use of cryotherapy to create scar tissue that will help the retina adhere to the back wall of the eye and remain flat. (Figure 3) The silicone band can then be placed around Surgical Technology for the Surgical Technologist:A Positive Care Approach, Care Technologist:A Positive for the Surgical Technology Surgical

From From the globe. Commonly, a mattress suture, usual-

ILLUSTRATION ly with a 5-nylon, is placed onto the sclera between the four rectus muscles. The silicone the scleral buckle procedure. After going over band can then be tied onto the sclera, as well as any of the patient’s questions, a consent form secured under the four rectus muscles, to keep should be signed. The patient is brought to the the buckle secure. (Figure 4) Before the buckle is operating room and placed in a supine position permanently tied in place, it is sometimes neces- onto the operating bed.After anesthesia has been sary to drain the fluid that has accumulated given (either general or a retrobulbar block), the under the retina. This can be accomplished by patient’s head is usually placed in some type of penetrating the globe with the use of a needle cradling device, such as a wedge shaped sponge, or beaver blade and allowing the fluid to escape, rendering it immobile during the procedure. At causing the retina to flatten. The surgeon then this time, some retina surgeons will verify the inspects the flattened retina with the indirect operative eye by looking into the dilated eye with ophthalmoscope. an indirect ophthalmoscope before prepping the If the eye appears to be too firm, a paracente- eye. Once this has been accomplished the circu- sis can be done into the anterior chamber of the lator is given permission to proceed with the eye.At this time, the mattress sutures can be per- prep. manently tied. The sutures that have been tied

The Surgical Technologist NOVEMBER 2002 14 FIGURE 5 Select ophthalmic instrumentation.

Serrefine 1-1/2" Jameson hook5" Von Graefe strabismus hook 5-1/2" Kirby fixation forceps 4" McCullough suturing for- ceps 4" Westcott tenotomy scis- sors 5-1/4" Miniature blade handle with chuck (fits Beaver blades) Iris scissors 4" Castroviejo eye speculum 3-3/4" Desmarres lid retractor 5-1/2" Castroviejo caliper 3-1/4" Iris tissue forceps 4" Graefe fixation forceps 4-3/8" Castroviejo suturing for- ceps 4" Courtesy of Miltex Inc,Bethpage,NY of Miltex Courtesy © 2002.

IMAGE Eye suture scissors (Gradle) 3-3/4" onto the muscles can be cut and removed. The regarding the use of antibiotic and steroid drops. Castroviejo needle holder conjunctiva can now be placed over the buckle The patient is also informed of any restrictions 5-1/2" (with lock) and sutured together, making sure the buckle is on physical activity. completely covered. At the end of the operation The success rate for scleral buckle surgery antibiotics and steroids are commonly injected depends on the preoperative status of the macu- into the conjunctiva to promote healing. After la. The anatomical success rate is 90 to 95%. Of being reversed from anesthesia, the patient can the eyes that are successfully reattached, about be brought to the recovery room and given 50% obtain a visual acuity of 20/50 or better if instructions. the macula was compromised. In eyes where the macula was attached prior to surgery, as many Postoperative notes as 10% have some loss of vision despite success- The patient is usually scheduled for an appoint- ful surgery. In most cases, this decrease in vision ment with the surgeon the next day. It is custom- is caused by cystoid and macu- ary to check visual acuity and intraocular pres- lar pucker. Without repair of the retinal detach- sure. Postoperative instructions are given ment however, visual recovery is poor.

NOVEMBER 2002 The Surgical Technologist 15 About the author 11. Wilkes ST, Beard CM, Kurland LT et al: The Pamela Daly has been a certified surgical tech- incidence of retinal detachment in nologist since 1984, and became certified with Rochester, Minnesota, 1970-1978. Am J the American Board of Surgical Assistants in Ophthalmol. 1982; 94:670. 2000. She attended Fox Valley Technical College 12. Felder DS, Brockhurst RJ. Retinal neovascu- in Appleton, Wisconsin. Pam is currently lariqation complicating rhegmatogenous employed with Texas Retina Associates in Dallas, retinal detachment of long duration. Am J Texas. She has specialized in for Ophthalmol. 1982; 93:773. the past six years. 13. Laqua H, Machemer R. Glial cell proliferation in retinal detachment (massive periretinal pro- Acknowledgements liferation). Am J Ophthalmol. 1975; 80:602. I would like to thank David Callanan, MD, and 14. Linner E. Intraocular pressure in retinal Wayne Solley, MD, for their contributions and detachment. Arch Ophthalmol (Suppl). support in assisting me with writing this article. 1966; 84:101. Thanks to Jim Daly for illustrating Figures 1-3 of 15. The Retina Society Terminology Commit- this article. tee. The classification of retinal detachment with proliferative vitreoretinopathy. Oph- References thalmology. 1983; 990:121. 1. Benson WE, Tasman W. Rhegmatogenous 16. Sasaki K, Ideta H, Yonemoto J, et al. Epi- retinal detachments caused by paravascular demiologic characteristics of rhegmatoge- vitreoretinal traction. Arch Ophthalmol. nous retinal detachment in Kumamoto, 1984; 102:669. Japan. Graefes Arch Clin Exp Ophthalmol. 2. Bill A. Blood circulation and fluid dynamics 1995 Dec;233(12): 772-6(Medline). in the eye. Physiol Rev. 1975; 55:383. 17. Schepens CL, Marden D. Data on the natural 3. Boldrey EE. Risk of retinal tears in patients history of retinal detachment. I. Age and sex with vitreous floaters. Am J Ophthalmol. relationships. Arch ophthalmol 1961; 66:631. 1983; 96:783. 18. La Heij EC, Derhaag PF,Hendrikse F.Results 4. Davis MD. Natural history of retinal breaks. of scleral buckling operations in primary Arch Ophthalmol. 1974; 92:183. rhegmatogenous retinal detachment. Doc 5. Fatt I, Skhantinath K. Flow conductivity of Ophthalmol. 2000; 100(1): 17-25 (Medline). retina and its role in retinal adhesion. Exp 19. Lincoff H, McLean JM, Nano H. Crkyosurgi- Eye Res. 1971; 12:218. cal treatment of retinal detachment. Trans 6. Haimann MH, Burton TC, Brown CK. Epi- Am Acad Ophthalmol Otolaryngol. 1964; demiology of retinal detachments. Arch 68:412-32. Ophthalmol. 1972; 56:700. 20. LincoffHA,Baras I,NcLean FM.Modification 7. Jaffe NS. Vitreous detachments. In: The Vit- to the Custodis procedure for retinal detach- reous in Clinical Ophthalmology. St. Louis: ment. Arch Ophthalmol. 1965; 73:160-3. CV Mosby; 1969: 83-98. 21. Texas Retina Associates, Dallas Texas Reti- 8. Morse PH, Aminlari A, Scheie HG. Light nal Tears and Detachments. www.texasreti- flashes as a clue to retinal disease. Arch Oph- na.com Accessed 5/2002. thalmol. 1974; 92:297. 22. Benson WE. Retinal Detachment: Diagnosis 9. Paufique L. The present status of the treat- and Management, 2nd ed. Philadelphia: Lip- ment of retinal detachment. Trans Ophthal- pincott; 1988: 1-13,53-65. mol Soc UK. 1959; 69:221. 23. Wu L. Retinal Detachments. Opthamology 10. Tasman WS. Posterior vitreous detachment Times [online journal]. June 27 2001, vol 2, and peripheral retinal breaks. Trans Am Acad No 6. www.ophthalmologytimes.com/ophthalmo Ophthalmol Otolaryngol. 1968; 72:217. logy times Accessed 5/2002

The Surgical Technologist NOVEMBER 2002 16 222 NOVEMBER 2002 CATEGORY 1

1. Which layer of the posterior wall provides nutri- 6. Which form of retinal detachment may be ents to the outer portion of the retina? caused by ? CECONTINUINGExam EDUCATION EXAMINATION a. sclera a. tractional b. photoreceptors b. rhegmatogenous c. choroid c. exudative d. macula d. all of the above

2. Which of the following structures does not 7. Which is mismatched? allow the passage of light focus light onto the a. Schepens:implant pioneer retinal surface? b. Custodies:buckling Rhegmatogenous a. lens c. Von Helmholtz:father of retinal detachment b. photoreceptors surgery retinal detachments c. iris d. Schepens:electrically illuminated binocular d. cornea indirect ophthalmoscope Earn CE credit at home 3. Which structure in the retina is aligned with the 8. A lid speculum is used to ____. You will be awarded one continuing education (CE) credit for central visual axis? a. immobilize the head recertification after reading the designated article and complet- a. sclera b. drain fluid under the retina ing the exam with a score of 70% or better. b. macula c. mark the area of detachment If you are a current AST member and are certified, credit c. vitreous body d. keep the eye open during surgery earned through completion of the CE exam will automatically d. choroids be recorded in your file—you do not have to submit a CE report- 9. Which of the following may be used to secure ing form. A printout of all the CE credits you have earned, includ- 4. Which is not a factor in the development of the buckle around the globe? ing Journal CE credits, will be mailed to you in the first quarter PVD? a. rectus muscles following the end of the calendar year. You may check the status a. age b. cannulated muscle hook of your CE record with AST at any time. b. trauma c. suture If you are not an AST member or not certified, you will be c. myopia d. a and c notified by mail when Journal credits are submitted, but your d. presence of a credits will not be recorded in AST’s files. 10. Cyrotherapy may be used to ___. Detach or photocopy the answer block, include your check or 5. Which of the following are mismatched? a. help the retina adhere to the back wall of the money order made payable to AST and send it to the Accounting a. floaters:differences in gel viscosity eye Department, AST, 6 West Dry Creek Circle, Suite 200, Littleton, CO b. enlarging field of deficit:hemorrhage b. drain fluid from the retina 80120-8031. c. circular floater:detached glial tissue c. mark the area of detachment Members: $6 per CE, nonmembers: $10 per CE d. retinal break:accumulation of subretinal fluid d. close the wound

222 NOVEMBER 2002 CATEGORY 1

Rhegmatogenous retinal detachments abcd abcd

❑ Certified Member ❑ Certified Nonmember 1 ❑❑❑❑ 6 ❑❑❑❑

Certification No ______2 ❑❑❑❑ 7 ❑❑❑❑

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Address______4 ❑❑❑❑ 9 ❑❑❑❑

City______State ______ZIP ______5 ❑❑❑❑ 10 ❑❑❑❑

Telephone ______Mark one box next to each number. Only one correct or best answer can be selected for each question.

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