Eyeworld

EW GLAUCOMA 109 C ataract surgery is the most commonly performed sur- gery on adults in the United States, and it is among the safest proce- dures. One relatively common post- op complication is an acute rise in IOP within the first day or so after surgery. IOP spikes on the day after cataract surgery can be quite high, into the 30-40 mm Hg range. "Cataract surgery often results in a long-term lowering effect on IOP," said Philip Chen, M.D., Uni- versity of Washington, Seattle. "In the immediate post-operative pe- riod, however, IOP may be acutely elevated due to retained viscoelastic devices, intraocular inflammation, or other factors." Consequences of IOP spikes For the majority of healthy eyes, this moderate IOP increase poses no sig- nificant threat to long-term visual health. But for patients with glau- coma whose optic nerves may al- ready be compromised, a significant post-op IOP spike can be dangerous. "Although the clinical implica- tions of a short-term IOP spike have not been clearly defined, elevated IOP remains a primary risk factor for glaucoma progression in patients with open-angle glaucoma," Dr. Chen said. "Cataract surgery results in a post-operative IOP spike in a signifi- cant proportion of both normal and glaucomatous eyes," he said. "Iden- tifying those patients at risk for an acute IOP spike would be clinically valuable, particularly in patients with known glaucomatous optic nerve damage." Robert Fechtner, M.D., director, glaucoma division, University of Medicine & Dentistry of New Jersey, Newark, agreed. "If we could iden- tify ahead of time those patients most likely to experience a signifi- cant IOP rise in the peri-operative period, we would be in a position to provide aggressive prophylactic ther- apy to blunt the spike." Risk factors for IOP spikes To address this relevant clinical issue, Dr. Chen and colleagues evalu- ated the post-op IOP profile of 80 patients with normal-tension glau- coma or high-tension open-angle glaucoma undergoing elective, un- complicated cataract surgery per- formed by a single surgeon (Dr. Chen himself). His customary peri-op practice is to ask patients not to use their IOP- lowering drops on the morning of surgery. "I worry about bacterial contamination from the bottles, so I do this as a measure of infection control," he said. To control IOP in the peri-op period, Dr. Chen pre- scribes oral acetazolamide to all of his glaucoma patients to be taken six hours after surgery. Overall, said Dr. Chen, 17 of the 80 patients (21%) exhibited an IOP spike of greater than 10 mm Hg from baseline on the first post-op day. "The risk factors for an IOP spike were open angles, implanta- tion of acrylic lenses, and refusal or by Tony Realini, M.D. Predicting pressure spikes after cataract surgery February 2011 March 2011 continued on page 110 Cataract surgery may cause a spike in IOP immediately after surgery Source: Jorge Alio, M.D.

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