Abstract
Abstract: :
Purpose: To determine if the multifocal electroretinogram (mfERG) is a useful tool in predicting progression of Age Related Maculopathy (ARM). Methods: The clinical files of 13 patients with ARM who had a mfERG performed approximately 3.5 years ago were evaluated. The initial mfERG (recorded on one eye per patient) and clinical results were compared to recent clinical findings to determine if the mfERG can be used to predict the progression of ARM. The patients ranged in age from 73 to 89 years (mean: 83 years). All subjects had visual acuity of 20/30 or better when the baseline mfERG was recorded. The patients were defined as having ARM due to the presence of soft drusen (>125 µm in diameter) in the macular area in the tested eye. Progression of ARM was defined as a 2 line or greater reduction in Snellen visual acuity, which was not attributed to any other ocular pathology. An abnormal mfERG recording was defined as a central increase in P1 implicit time of 2 standard deviations or more from the average of 25 age–matched normal subjects or a decrease in log density of 2 SD or more. Results: 7 of the 13 patients have experienced a significant reduction in visual acuity and 6 have maintained stable visual acuity in the 3.5 years since the baseline mfERG. All 7 with progressive acuity loss had central P1 implicit times delayed by more than 2 SD at baseline and 4 had reduced log density more than 2 SD. Of the 7 patients with significant reduction in central visual acuity, 4 progressed to wet ARMD and 3 developed severe dry ARMD. Of the 6 subjects who maintained stable visual acuity, 5 had a normal P1 implicit time and 4 had normal log density at the baseline. P1 implicit time at baseline was able to predict the subsequent reduction in central visual acuity with statistical significance (chi square: 9.48; p<0.01) but log density was not statistically significant (chi square: 0.74; P∼0.4). Conclusions: Delayed P1 implicit time on mfERG predicted the subsequent loss of central visual acuity due to progression to ARMD. Further research in a larger population is needed in order to determine if patients with ARM would benefit from a mfERG evaluation prior to aggressive preventive therapy. Supported by NEI Grant: T32 EY07043
Keywords: age–related macular degeneration • electroretinography: clinical