Eyeworld

EW GLAUCOMA 43 When it comes to peripheral iridotomy, placement is the key to patient satisfaction P erformed by widening the anatomical angle and re- ducing the potential of pupillary block, laser pe- ripheral iridotomy (LPI) is a fairly common procedure for pa- tients with narrow angles as a pro- phylactic intervention. If left untreated, those same patients run a higher risk of developing narrow angle or acute angle-closure glau- coma. Angle-closure glaucoma re- mains a leading global cause of irreversible blindness. Because the procedure is relatively benign, "it's usually one of the first procedures we let residents perform," said Robert J. Noecker, M.D., former vice chair, University of Pittsburgh Medical Center Eye Center, Pa., and currently in private practice. However, an inconveniently placed hole may lead to complaints of glare or diplopia, he said, and will not be well tolerated by asympto- matic, younger patients. "If the patient is older with some degree of cataract or has been going in and out of angle closure, that patient is uniformly happy to be rid of it—nothing you do is going to be worse than an angle closure," he said. "Those who are most likely bothered by a PI are totally asympto- matic, with possibly vague or very mild symptoms." PI placement If the PI hole is placed "totally under the eyelid, that would be the best scenario," Dr. Noecker said. Patients with "lower-hanging eyelids" are not likely to complain about glare "as long as the hole is up toward 12 o'- clock," he said. Likewise, patients with bigger eyes and eyelids above the limbus are not likely to notice the PI. "It's the patients with a PI right at the intersection of the eyelid and the tear film who have a prismatic effect that causes secondary glare," he said. To compensate, some sur- geons place the hole at 3 o'clock or 9 o'clock. Dr. Noecker said when lasers were initially used for PIs, that location was typical, and PIs are gen- erally well tolerated in those loca- tions. These days, however, surgeons are commonly using an Abraham lens (Ocular Instruments, Bellevue, Wash.) during surgery to help limit eye movements and blinking and to act as a "heat sink" to minimize col- lateral damage, Dr. Noecker said. Upon occasion, the PI will be more difficult when being placed superi- orly "when the conjunctiva comes down over the cornea a bit more," making the laser view more difficult, he said. Placing the PI at 3 and 9 eliminates those potential problems, he added. He advised surgeons to ensure the hole is open, not to place it so far peripherally it's not readily viewed, and to use pilocarpine if necessary to constrict the pupil. Patient selection, patient choice What has been underappreciated in the past by ophthalmologists is how annoying the side effect of the PI may be, Dr. Noecker said. "You're taking asymptomatic patients and telling them it's a good idea to have this surgery even though they're not experiencing anything because they might de- velop a problem down the road," he said. "Then, post-operatively, they've got glare or can see light coming through this hole that no one told them about, and it's upset- ting to them." He said the first conversation clinicians should have with patients is about the possibility of glare so if it occurs, patients won't be alarmed. This also allows patients to weigh the risks and benefits themselves and decide if they want to move ahead. "I council patients that glare is a side effect that gets better over time," he said. If the patient is older, developing a cataract will help re- duce the glare simply by clouding the lens. Still others can learn to ig- nore it, he said. "In extreme cases, you can do corneal tattooing, which would make the cornea opaque and allevi- ate the glare issue," he said. Most people with narrow angles, "won't progress to angle-closure glaucoma. It's just that angle-closure is so horrible, you want to avoid it," Dr. Noecker said. But will PIs ensure patients won't progress? The literature is in- conclusive, yet the procedure re- mains standard. In 2009, one study found 15 of 52 eyes (28%) of people classified as primary angle-closure suspects developed primary angle- closure within 2 years of undergoing PIs. 1 Yet another study found in Asian eyes, up to 20% had residual angle-closure after LPI. For that rea- son, Dr. Noecker said "it's always a good idea to leave the decision about undergoing PIs in the pa- tient's hands if the patient is asymp- tomatic." EW References 1. Ramani KK, Mani B, George RJ, Lingam V. Follow-up of primary angle closure suspects after laser peripheral iridotomy using ultra- sound biomicroscopy and A-scan biometry for a period of 2 years. J Glaucoma. 2009;18(7):521-7. 2. He M, Feidman DS, Ge J, Huang W, Jin C, et al. Laser peripheral iridotomy in primary angle-closure suspects: Biometric and gonio- scopic outcomes. The Liwan Eye Study. Oph- thalmology 2007;114:494-500. Editors' note: Dr. Noecker has no finan- cial interests related to his comments. Contact information Noecker: Robertnoecker@comcast.net February 2011 July 2011 by Michelle Dalton EyeWorld Contributing Editor Location, location, location Dr. Cantor acknowledged that seeing a patient with UGH syn- drome isn't a common, everyday oc- currence, but the glaucoma specialist does see a case every month or two. "It's not a rare bird you never see and it's not something you see every week either," he said. "But it does happen and unless it's on your radar, you're prone to miss it. If you see prolonged inflammation or some pigment floating around in the ante- rior chamber, think of this as a pos- sible cause. Inspect the lens closely, and ensure that the haptics are both in the bag. It's easy for a haptic to not get in as planned." EW Editors' note: Drs. Cantor and Condon have no financial interests related to their comments. Contact information Cantor: lcantor@iupui.edu Condon: garrycondon@gmail.com Could continued from page 42 Cogan History Society marks 25th anniversary M ark your calendars. The Cogan Ophthalmic History Soci- ety is celebrating its 25th anniversary at the National Li- brary of Medicine, Bethesda, Md., on March 30, 2012. Formally known as the American Ophthalmic History Society, it was renamed after the late David G. Cogan, M.D., professor and chairman of ophthalmology, Harvard Medical School, Boston. The society meets annually to discuss the history of ophthalmology. Talks can range from a survey of ophthalmological in- struments to the curious career of Ida Mann, D.B.E., M.B., D.Sc., M.A. The last meeting took place this past April in Philadelphia. Forty soci- ety members attended, including many international scholars, and lis- tened to 30 papers presented on ophthalmic history. For more information on the next Cogan Society meeting, or to join, visit cogansociety.org or contact George Bohigian, M.D., president, Cogan Ophthalmic History Society, at bohigian@att.net.

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