Abstract
Abstract: :
Purpose: To assess the neuroprotective effect of a topical α2-agonist in patients with retinal dystrophies. Methods: A prospective, randomized, placebo-controlled, double-masked study design was employed. After initial assessment of compliance at two months, 26 patients with retinal dystrophies were included. One eye was treated with Brimonidine tartarate 0.2% (Alphagan, Allergan, USA) twice daily while the fellow eye received artificial tears. An ophthalmic exam, Goldmann visual fields, contrast sensitivity, color vision, and full field electroretinography (FFERG) were performed in each eye. These tests were repeated every 6-8 months. Results: Seventeen of the 26 patients recruited completed at least 18 months of follow-up (range 18-36 months, mean 29.3 months). The leading cause for dropout was allergic reaction, proven by re-challenge. At the conclusion of the study, visual acuity, color vision and contrast sensitivity were similar in treated and control eyes. A trend towards smaller visual field loss was observed in the Brimonidine-treated eyes when assessing absolute visual area loss. However, this trend was not observed when assessing percent of visual field loss. FFERG amplitudes were severely reduced on initial exam in all patients. During the course of the study there were relatively significant fluctuations in ERG amplitudes making the comparison between the treated and control eyes difficult. Conclusions: In this pilot study we found a trend for slower progression of the retinal dystrophy in eyes treated with Brimonidine according to only one of the parameters that were examined. Further studies that include a larger number of patients and a longer follow-up period are needed to clarify the potential neuroprotective effect of α2-agonists in human retinal dystrophies.
Keywords: neuroprotection • retinal degenerations: hereditary • clinical research methodology