Abstract
The multi-focal electroretinogram (mfERG) acquires spatially resolved retinal signals that can facilitate diagnosis and treatment of visual disorders. However, much information contained in the recorded signals remains unexploited. Here, we use the mfERG to detect age-related changes in retinal recovery from a photopic double-flash response. mfERGs were recorded from 33 normal subjects with no ocular pathology (mean age: 39.4 years, range: 18.2 - 57.8 years) using the VerisPro software (EDI) that allows extraction of retinal responses at different inter-stimulus intervals (ISIs) and different flash combinations. 103 hexagons and 2.66cd sec/m^2 stimulus luminance were used. The responses were grouped into macular and peripheral retinal areas. In the macular region, the stimulus subtended a ~10 degrees radial area centered on the fovea with the central 1 degree excluded. The peripheral stimulus formed a ring with inner and outer radii ~10 and 20 degrees, respectively. Single-flash responses preceded by a double flash were extracted from the signal. Age-related changes in retinal recovery were found for the macular, but not peripheral retina at the minimum ISI (13.3ms). A t-test comparing the 10 youngest and the 10 oldest observers revealed a statistically significant difference (p<0.05, ?=0.05). For longer ISIs no difference was found. The results suggest that fast adaptation in the macular area is more vulnerable to aging than the peripheral area and that, for the age range covered here, the older retina has the capacity to fully recover between 13.3 and 26.6ms and respond like a young retina. These regional differences cannot be explained by pre-retinal factors.
Meeting abstract presented at OSA Fall Vision 2012