EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
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by Michelle Dalton EyeWorld Contributing Writer Highlights from AAO's Retina Subspecialty Day Study results on geographic atrophy, diabetic macular edema, and neovascular age-related macular degeneration were among the highlights T he 2013 American Academy o f Ophthalmology's Retina Subspecialty Day boasted segments on vitrectomy, geographic atrophy (GA), diabetic retinopathy (DR) and diabetic macular edema (DME), neovascular age-related macular degeneration (AMD), and imaging, among others. Here, a brief overview of some of the highlights. MAHALO phase 2 results GA is characterized by an irreversible loss of retinal tissue in the macula resulting in permanent blind spots in a patient's central vision; there is currently no approved therapy for its treatment. Lampalizumab is an antigen-binding fragment (Fab) of a humanized, monoclonal antibody directed against complement factor D, according to developer Roche (Basel, Switzerland). Complement factor D is a rate-limiting enzyme in- volved in the activation of the alter- native complement pathway (ACP), a component of the immune sys- tem's natural defense against infec- tions. Genetic polymorphisms as well as hyperactivity of the ACP have been implicated in the development of AMD including GA, Roche has said. Carl D. Regillo, MD, professor of ophthalmology, Thomas Jefferson University, and director of the retina service, Wills Eye Institute, Philadel- phia, reported the phase 2 results on a sub-population of GA patients who were positive for the complement factor I biomarker. MAHALO enrolled 129 patients with bilateral geographic atrophy secondary to age-related macular degeneration in the absence of choroidal neovascu- larization randomized to sham arms (n=42), 10 mg lampalizumab dosed monthly or every other month. Those who received monthly lampalizumab (n=43) had a 44% decrease (P<0.005) in the rate of disease progression at 18 months. When lampalizumab was adminis- tered every other month (n=44), the rate of disease progression was de- creased by 18% (P=0.23) in the bio- marker defined subgroup of patients. Of particular interest, only those pa- tients who were positive for the bio- m arker showed treatment effect. Lampalizumab showed a 20.4% reduction rate in the area of GA at 18 months that was statistically sig- nificant (P=0.1170) per pre-specified protocol criteria in patients with GA, Dr. Regillo said. "There were no intraocular in- fections or unexpected/unmanage- a ble serious adverse events," he said. "The MAHALO results suggest the complement factor I biomarker is both prognostic for GA progression and predictive for lampalizumab treatment response." DME studies Tight glycemic control reduces the risk and rates of progression of DR, said Allen C. Ho, MD, director of retina research, Mid Atlantic Retina and Wills Eye Institute. "But what ophthalmologists may not know is that lipid modula- tion (fenofibrate) reduces progres- sion of DR, but not cardiovascular events," he said. A study of patients with type 2 diabetes found fenofi- brate reduced the first laser treat- ment by 31%, reduced macular edema by 31% and proliferative retinopathy by 30%. The compound reduced the progression of DR by 79% in those with pre-existing retinopathy. "Antivascular endothelial growth factor (VEGF) likely has a class effect on DME," he said. Ranibizumab 0.5 mg showed a 35.9% regression of more than two steps over 24 months and 14.5% regression of more than three steps; ranibizumab 0.3 mg showed a 37.2% and a 13.2% regression, respectively. At 36 months, ranibizumab 0.3 mg produced a 39.3% regression of at least two steps and a 13.2% regres- sion of at least three steps. "The cumulative probability of clinical progression of DR at two years was 33.8% in sham-treated eyes compared to about 11% in ranibizumab-treated eyes," he said. Tyrosine kinase with immune globulin-like and EGF-like domains 2 (Tie2) receptors regulate much of the signaling from surrounding cells and extracellular matrix and may have potential in the treatment of March 2014 136-137 Retina_EW March 2014-DL_Layout 1 3/6/14 4:15 PM Page 136