EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
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88 EW GLAUCOMA February 2011 February 2012 Does intravitreal anti-VEGF therapy lead to glaucoma? by Tony Realini, M.D., M.P.H. Prevalence of elevated IOP "We conducted a retrospective chart review of 149 eyes of 133 treatment- naïve neovascular AMD patients with no prior history of glaucoma," she said. "As would be expected of a group of patients with AMD, the mean age of the group was 81 years, and 61% of the eyes were phakic. The mean pretreatment IOP of the group was 14.9 mm Hg. These pa- tients were then treated with anti- VEGF therapy and followed for a mean of 21.2 months. Over that pe- riod of time, they received an aver- age of 14.3 injections per eye." IOP elevations of 21 mm Hg or above and 25 mm Hg or above were noted during follow-up, as were any IOP elevations of 6 mm Hg or more above baseline, she said. "Overall, eight patients—6% of our cohort—experienced an IOP ele- vation," she said. This number is in agreement Blue light tonometry is used to measure IOP—elevated pressure may be a complication of anti-VEGF therapy Source: National Eye Institute, National Institutes of Health A nti-VEGF therapy has rev- olutionized the treatment of neovascular age-related macular degeneration (AMD) in the past decade. The vast majority of treated pa- tients—in excess of 90%—maintain vision for 2 years or more, and a substantial proportion—about 35%—gain three of more lines of vision upon initiation of therapy. New continued from page 86 of despair for both the surgeon and the patient. To this end, the applica- tion of tissue glue would seem intu- itively beneficial. However, early explorations with older adhesive technology—such as cyanoacrylate glue—produced unsatisfying results. Fibrin-based adhesives, conversely, might offer more application in the ophthalmic surgery arena. "Fibrin sealants were developed during World War II to manage acute hemorrhage on the battle- field," said Angelo Tanna, M.D., assistant professor, ophthalmology department, Feinberg School of Medicine, Northwestern University, Chicago. "Fibrin clots are formed when fibrinogen and thrombin come into contact with one another," ex- plained Dr. Tanna. Several commer- cial systems utilizing combinations of fibrinogen and thrombin are available, including one in which both components are preloaded in dual syringes and delivered simulta- neously using a single plunger. Dr. Tanna uses this tissue glue to close the conjunctiva in some of his tube-shunt cases. "I use it in those eyes with very delicate conjunctiva, where sutures might tend to shred or cheesewire the tissue. The cost is about $75, and it produces a smooth, comfortable seal along the entire length of the wound with the need for fewer sutures, all in less time than a traditional closure." EW Editors' note: The doctors mentioned have no financial interests related to this article. Contact information Pro: mpro2020@yahoo.com Sarkisian: steven-sarkisian@dmie.org Tanna: atanna@northwestern.edu When used as approved, these agents must be injected into the vit- reous cavity as frequently as once a month, with no clear end to ther- apy. Most studies of intraocular anti- VEGF therapy have been of 1- or 2-year duration, so the longer-term side effects of ongoing therapy have not been well characterized. "Intraocular pressure elevations were not noted as complications of anti-VEGF injections with ranibizumab (Lucentis, Genentech, San Francisco) in the ANCHOR and MARINA trials," said K. Bailey Freund, M.D., clinical associate pro- fessor, ophthalmology department, Langone Medical Center, New York University, New York. "But recent reports suggest that sustained ocular hypertension can occur." with a prior study conducted by the same group. In that study, 474 eyes of 349 patients were included, and patients with pre-existing glaucoma were not excluded as long as their IOP was 21 mm Hg or below at the time anti-VEGF therapy was initi- ated. "In that cohort," she said, "we defined an IOP elevation as IOP above 21 mm Hg on two or more visits after beginning anti-VEGF therapy. We observed a sustained IOP elevation in 39 eyes, or 8% of the cohort." Predictors of elevated IOP Dr. Freund's team also looked for predictive factors that might identify patients at risk for IOP elevations arising due to anti-VEGF therapy. In the group with 133 patients, she said, "Our analysis demonstrated a significant effect of the total num- ber of anti-VEGF injections on the probability of developing elevated IOP." The number of injections was predictive of IOP elevations of both 21 mm Hg and 25 mm Hg or above, as well as elevations of 6 mm Hg or more from baseline, she said. "Patients whose IOP was 21 mm Hg or higher had a mean of 26.6 injections while patients with IOP below 21 mm Hg had only 13.7 in- jections on average," she explained. For an IOP of 25 mm Hg or higher, the corresponding average numbers