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40 EW CATARACT February 2013 Touching problems by Maxine Lipner Senior EyeWorld Contributing Writer eye without touching the lens, but he acknowledged that this could have been an issue. With vitrectomy there can also be mechanical trauma to the lens, Dr. Vasavada finds. He links it to the use of fine instruments such as forceps, scissors, or vitrectors. Dr. Packer warned that if a cataract develops rapidly after a patient undergoes a vitrectomy, this can be a sign that the posterior capsule was broken by the vitrector. ���That���s a risky type of cataract to do because the capsule is not intact and you can very easily drop the whole lens,��� he said. ���I haven���t done that but I certainly know people who have.��� Removal strategies Inadvertently touching a lens may cause ICL-related cataracts, according to several experts. Dealing with practitionerprecipitated cataracts W hen it comes to agerelated cataracts, there���s a sense of inevitability about it all, a fact of life if you will. However, in cases where a cataract develops due to an inadvertent touch on the lens, it���s a different story. Here a precipitating event such as an anti-VEGF injection gone array, difficulty with a vitrectomy in a phakic eye, or even an accidental touch during implantation of a phakic intraocular lens can cause the cataract. While not very common, these are of some concern particularly with posterior segment procedures being undertaken more frequently, according to Abhay R. Vasavada, M.D., director, Iladevi Cataract & IOL Research Centre, Raghudeep Eye Clinic, Ahmedabad, India. ���The most common is following the vitrectomy procedure, but I have seen a couple even after intravitreal injections,��� Dr. Vasavada said. Theoretically, in the case of injections, he stressed, it shouldn���t happen because the drug is deposited in the mid-vitreous cavity, but in actuality it does occur. ���It does happen���it���s not easy for the surgeon to be absolutely precise in the direction (of the injection),��� Dr. Vasavada said. ���So a minor complication or a misjudgment can lead to either zonule damage where you damage the suspensory zonules or to the peripheral equator of the lens or of the posterior capsule.��� It is the nature of the lens itself that causes cataracts resulting from an inadvertent touch of the lens to occur, explained Richard L. Lindstrom, M.D., adjunct professor emeritus, University of Minnesota, Minneapolis. ���We know the physiology of the human lens is such that if we traumatize the lens epithelial cells, which sit right under the anterior capsule, they usually respond by proliferating, and that results in a cataract,��� Dr. Lindstrom said. Common causes The most common type of these lens-touch cataracts that he has come across is that caused during implantation of a phakic intraocular lens, usually of the ICL (implantable collamer lens, STAAR Surgical, Monrovia, Calif.). He finds that if the insertion of the ICL is difficult or traumatic and the lens is touched too much, soon after surgery an anterior, subcapsular cataract can result. ���In addition, if the sizing isn���t right, such that the ICL doesn���t properly vault away from the front surface of the natural lens so that it touches, then you get a cataract,��� Dr. Lindstrom said. Because the natural lens thickens with age, even if there is plenty of clearance for the ICL vault initially, this must be watched to make sure that contact doesn���t inadvertently occur with time. While not terribly prevalent, Dr. Lindstrom finds that this ICL-related type of cataract does happen. ���There is a lot of debate, discussion, and argument about how frequently that occurs, but it appears to be as high as 10% in 10 years,��� Dr. Lindstrom said. ���Because we do phakic IOLs in our practice, that���s one that we���re always watching for.��� Likewise, Mark Packer, M.D., clinical associate professor of ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, Ore., always keeps the possibility of an inadvertent touch to the lens in mind when implanting an ICL. ���These are very myopic eyes that are getting ICLs so you have a lot of room to work, and you usually have a viscoelastic to cushion the lens and push it back, but things can happen,��� Dr. Packer said. He recalls a case in which he was injecting an ICL and it flipped over. He was able to successfully flip it back inside the In removing this type of cataract, Dr. Packer advised the practitioner to assume that the capsule is open and avoid hydrodissecting. ���If you squirt fluid in there as you normally would, it���s very likely that the capsule will split because it���s got this point of weakness,��� Dr. Packer said. Instead, an inside-out approach is used. This involves separating the endonucleus from the epinucleus. ���You take out the endonucleus first,��� Dr. Packer said. ���It���s great if you can rotate it and viscodissect the epinucleus and then the cortex.��� When removing one of these lens-touch cataracts, Dr. Vasavada urged practitioners to do so within a few days of the precipitating incident. During the removal process, he advises practitioners to set low phacoemulsification parameters and use dispersive viscoelastic such as Viscoat (Alcon, Fort Worth, Texas) as a cushion. ���What we need is a viscoelastic that stays around on the top of the defect,��� Dr. Vasavada said. He stressed the importance of closed-chamber techniques in such instances. Otherwise, Dr. Vasavada said that during the lens removal, a defect in the posterior capsule can expand as a result of the capsule and zonules moving forward anteriorly. ���When you retract the instrument out of the eye, you need to inject through the other sideport a viscoelastic so that chamber never collapses and the chamber contours are maintained all the time,��� Dr. Vasavada said. Once the cataract is removed, assuming that the posterior capsule