Is Oral Agent Effective Against Geographic Atrophy?
August 17, 2009
Oral fenretinide may be effective in slowing down or halting macular degeneration due to geographic atrophy. Most cases of macular degeneration are the non-exudative or dry form and geographic atrophy represents an aggressive subset of dry macular degeneration.
Geographic atrophy is purportedly due to a buildup of lipofuscin and A2E in the RPE leading to death of the RPE and overlying photoreceptors. Earlier hopes that xanthine and zinc, due to their antioxidant properties, would slow down progression of GA have been disappointing.
Patients were randomly assigned to receive fenretinide daily or a placebo. Analysis included patients completing at least 12 months of follow-up. Multiple parameters were used to evaluate patients including visual acuity, night vision, reading rate, contrast sensitivity, perimetry and complete bloodwork, specifically retinol-binding protein (RBP). The primary endpoint was the growth/reduction of the GA lesion.
The study found a dose related correlation between doses of fenretinide and serum RBP. No correlations were determined prior to the start of oral treatment. The size of the GA lesion was also affected by the fenretinide although the smaller lesions appeared to respond better than larger lesions.
What does this mean? As we better understand the pathology of non-exudative degeneration, new therapeutic possibilites emerge. It is exciting that there may be an effective treatment, other than intraocular injections, to treat macular degeneration. It is even more exciting that there may be an effective treatment for the more aggressive, more prevalent, form of the dry, or non-exudative, macular degeneration. Complete results of the study are expected in 2010.
Link to the article.
Randall V. Wong, M.D.
Ophthalmologist, Retinal Specialist
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