EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/87458
October 2012 Challenging cataract cases February 2011 To repair or to replace: That is the question in trauma cases by Jena Passut EyeWorld Editor After many consultations, family decides on procedure that's best for explosion victim W hen a 19-year-old male whose eye was injured in a fireworks accident presented to Steven G. Safran, M.D., Lawrenceville, N.J., he was faced with a decision—repair the damaged iris or replace it altogether with a pros- thesis. The patient and his mother had been to several surgeons and their hopes were dimming. "The mother contacted me after bringing [the patient] to various sur- geons/institutions and hearing a poor prognosis for visual and func- tional recovery of the iris, which left her somewhat dismayed," Dr. Safran said. The young man had a white cataract with a fibrotic anterior cap- sule, an irregular inferior lens border suggestive of zonular weakness, and a complete iridodialysis inferiorly with evidence of iris atrophic changes. "I told the mother that I thought I could do a pretty good job of restoring iris anatomy, but they might want to consider an iris pros- thesis," Dr. Safran said. "After discussing the details of the device and the surgery I would do to repair rather than replace the iris, the fam- ily decided to have me do the sur- gery with the belief that this might give a greater amount of iris func- tion than a prosthesis." Dr. Safran also consulted a num- ber of anterior segment surgeons, in- cluding Kenneth Rosenthal, M.D., New York Eye and Ear Infirmary, New York, who has extensive experi- ence with the foldable iris di- aphragm from HumanOptics (Erlangen, Germany) and who is the co-inven- tor (with Volker Rasch, M.D.) and first surgeon to implant the first modular iris implant. Dr. Rosenthal agreed that a restoration of the iris anatomy was possible in this case. "When Dr. Safran first consulted me about this case, I noted that the pupillary ruff and most likely the sphincter muscle were intact, and the primary defects were a probable zonular dehiscence underlying a clean iridodialysis," Dr. Rosenthal said. "I recommended that cataract surgery with possible use of a capsu- lar tension ring (CTR) and a primary repair of the iridodialysis be per- formed." Where to begin Pre-op images of a 19-year-old male who was injured in a pyrotechnic explosion. He had a white cataract with a fibrotic anterior capsule, an irregular inferior lens border suggestive of zonular weakness, and a complete iridodialysis inferiorly with evidence of iris atrophic changes It's difficult to create countertraction against the leading edge of a tear when zonular compromise is pres- ent. While one approach is to start the rhexis at or near the area of zonular dialysis, Dr. Rosenthal said, "I prefer to perform the rhexis by starting at the side opposite the area of zonular dialysis, and tearing toward the dialysis, which changes the vector force toward, rather than against, the weakened area. Some- times it is necessary to begin the rhexis counterclockwise, up to and within the area of the weakness, and then continue the rhexis from the opposite side, tearing, for example, clockwise, until the leading edges of the rhexes meet, again lessening capsular tension." In cases of zonular compromise, Post-op image after iris repair (pre- and post-dilation). The patient is 20/20 and the pupil has rounded out. Source (all): Steven G. Safran, M.D. the need for additional capsule sup- port is essential. "My preferred method is to sup- port the capsule from within by ei- AT A GLANCE • VisionBlue may stain the vitreous in cases with zonular weakness • Iris retractors can be used to help tear the capsule and hold the iris out of the way while the surgeon performs the rest of the surgery • The decision to repair the iris rather than replace with a prosthesis "is one we will be learning how to answer better for each patient over the next few years. The repair has its own risks but provides a very nice outcome here," Dr. Safran said • The use of a prosthesis would "standardize" the outcome and make the surgery easier to perform, but may come with greater cost to the patient and with far less pupil function • Long-term outcomes with the iris prosthesis are still being studied, while the repair should last for decades EW FEATURE 73 http://tinyurl.com/cnhsgar Watch this video on your smartphone or iPad using your QR code reader. (Scanner available for free at your app store.) ther insufflating the capsule with a generous amount of a highly reten- tive viscoelastic such as Healon 5 (Abbott Medical Optics, AMO, Santa Ana, Calif.), which will maintain tension within the capsule locally, or by early placement of a CTR with or without a Cionni ring modification, or an Ahmed segment, to buttress the capsule's support within the bag," Dr. Rosenthal said. "I often use these two modalities together to create a strong support system in the absence of intact zonules." Capsular hooks, which may be needed with diffuse or profound zonular deficiency, can cause a tear in the edge of the capsule or an in- advertent radialization of the rhexis, Dr. Rosenthal added, although sev- eral new modified designs (such as continued on page 74