Abstract
Purpose: :
To determine if genetic risk factors play a role in retinal dysfunction noted in AMD patients as assessed using standard multifocal electroretinography (mfERG).
Methods: :
A total of 62 male subjects, 28 patients and 34 unrelated age-matched controls, were included in our study. Patients were diagnosed through ophthalmologic examination, and subcategorized by criteria defined by the Age-Related Eye Disease Study (AREDS). All patients included in the study exhibited clinical features of mild to moderate ARMD, namely categories 2 and 3. Controls lacked macular drusen and exhibited no clinical evidence of any retinal disorder. DNA was genotyped by direct genomic sequencing or RFLP analysis for AMD risk alleles that together account for ~75% of the combined AMD genetic risk ((CFH (rs1061170), HTRA1 (rs11200638), ARMS2 (rs10490924), C3 (rs2230199)). Standard mfERGs were recorded on all subjects; responses were analyzed in concentric ring averages and N1 and P1 amplitudes and P1 latency of the average waveforms were noted.
Results: :
Patients with a greater number of AMD risk alleles were more likely to have delayed mfERG responses from the foveal and parafoveal areas. When individual genes were evaluated, mfERG delays were more pronounced for patients carrying 1 or 2 risk alleles for HTRA1 and ARMS2, while there was no clear relationship for C3 or CFH. There was also no clear relationship between mfERG amplitude and genetic risk alleles.
Conclusions: :
Delayed mfERGs have been previously reported in AMD patients. In this study, we note that risk alleles for some AMD-related genes (HTRA1, ARMS2) are more strongly associated with mfERG delays than others (C3, CFH). This suggests that the different genetic risk factors may manifest with different pathophysiological signatures.
Keywords: age-related macular degeneration • electroretinography: clinical • genetics