JAN 2012

EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.

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Page 12 of 71

January 2012 EW NEWS & OPINION 13 Figure 5 Figure 6 was completely collapsed and had fi- brosed years earlier, and he had an open posterior capsule with no evi- dence of a separate continuous ante- rior rhexis opening. Dr. Goldberg commented: "The key to this case is analyzing the source of the problem—a sulcus- placed PCIOL without optic capture overlying a damaged capsule in the enlarged posterior chamber of a high myope. The iris should not be con- sidered for suture fixation, so the surgeon should be prepared with his/her best technique for scleral fix- ation. The added risk of exchanging IOLs is outweighed by the advan- tages of exchanging for a better- designed IOL (e.g., larger optic diam- eter, longer haptics, eyelets for scle- ral fixation)." Dr. Khan commented: "I don't think I've ever seen anything like this before with the posterior bow- ing of the iris and transillumination defect. This seems like a cross be- tween reverse pupil block and pig- ment dispersion syndrome so the first thing I would do is try a PI; it might require a tap with a 30 g nee- dle to clear up the cornea … Failing this I would consider explanting the lens and letting the eye settle down … It's an interesting case." Most of the participants in this case discussion felt that there was an "unusual" or "weird" anatomy here, and this was indeed the case. It turned out that this patient did have reverse pupillary block. The reverse pupillary block created a vicious cycle of tension on the peripheral iris, stretching it, which caused in- termittent bleeding. The blood com- bined with pigment dispersion caused by iris contact with the implant (exacerbated by pseudophakodonesis) caused clog- ging of the meshwork, build-up of pressure in the anterior chamber, and further pressure placed on the iris against the implant, creating a ball valve effect similar to what you see during cataract surgery in high myopes when you may get reverse pupillary block during surgery and have to lift the iris to break it. In this case all I needed to do was a laser peripheral iridotomy and the situation completely resolved. Figure 5 is an image of the eye im- mediately after the iridotomy. The iridotomy broke the reverse pupillary block and the pressure dropped within an hour into the 20s. The next day the IOP was in the low teens where it has stayed for over a year without medication. Figure 6 is an image of his go- nioscopy after the iridotomy. Notice how much less concave the iris is. Figure 7 is an OCT image. No- tice that the iris is flat and there is a gap between the iris and the surface of the IOL. (Compare this to the im- ages taken before PI when the iris was distended back and jammed up against the optic.) I have now seen four patients in the last 18 months with a similar presentation of pseudophakic re- verse pupillary block causing ele- vated IOP associated with either pigment dispersion, hyphema, or iris capture. All responded to laser irido- tomy immediately, which broke the pupillary block. Figure 8 is before and after im- ages of the iris from a second patient that presented with pseudophakic reverse pupillary block. Note that this patient had the same "finger"- Figure 8 shaped transillumination defects as the first patient did. This is due to the chronic extreme distension of the peripheral seen in these cases. Iris stretching, as well as iris contact with the IOL, may lead to hyphema while iris contact with the optic and haptics may lead to pigment disper- sion, contributing to blockage of the trabecular meshwork. I believe this problem is fairly common but not recognized. All four patients I've treated were com- pletely cured with laser iridotomy. In one patient who presented with continued on page 14 Figure 7

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