Abstract
Purpose: :
To assess the electroretinographic function in a subset of participants with age- related macular degeneration who received prophylactic laser treatment in one eye as part of the CAPT study.
Methods: :
Multifocal electroretinography (MERG) was performed in 20 subjects for both eyes at baseline, 2 years, and 5 years following application of prophylactic laser according to the CAPT protocol in one eye. Analysis was performed on the first-order kernel of the MERG utilizing 3 rings which correspond to the central macula, the ring in which laser is applied, and a peripheral ring. Comparison was performed between control and treated eyes at each timepoint, and within each group for changes over the 5 year followup.
Results: :
At baseline, control and treated eyes had equivalent MERG first-order kernel responses (response density and peak latencies) in all three rings. Analysis of data by location does not find a particular region more affected by changes over five years. Although amplitude response was preserved, there was a significant delay in peak latency (range 1-4 ms) of outer retinal MERG responses, (p < 0.01) that was equivalent in control and treated eyes. There is no significant difference between the two groups at 5 years.
Conclusions: :
Administration of low intensity laser in a grid encircling the central macula did not result in any significant changes in MERG response when compared to fellow (control) eyes. This corresponds to the overall finding of the CAPT study that progression of AMD was equivalent in laser treated and control eyes. The delay in latency of retinal response over 5 years is associated with aging or AMD.
Clinical Trial: :
www.clinicaltrials.gov NCT00000167
Keywords: age-related macular degeneration • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • electroretinography: clinical