Electrophysiological study of age-related macular degeneration

Purpose
To evaluate the effects of age-related macular degeneration (ARMD) on electrophysiological tests and to correlate between electroretinogram (ERG) and optical coherence tomography.
Patients and methods
Fifty control participants (100 eyes) and 100 patients (100 eyes) with ARMD were examined clinically. ERG, multifocal electroretinogram (MFERG), standard ERG, fluorescein angiography, and optical coherence tomography were performed.
Results
ERG responses were decreased in all types of ARMD, especially in geographic atrophy. The amplitudes of scotopic ERG were slightly decreased, without a change in implicit times. The amplitudes of oscillatory potential were significantly decreased and photopic responses were also decreased in geographic atrophy, choroidal neovascularization, and pigment epithelium detachment. MFERG shows abnormalities not only in the central ring but also in all rings (central, paracentral, and peripheral). There were negative correlations between central macular thickness and the amplitude of MFERG of the central ring and a positive correlation between central macular thickness and latency of MFERG of the central ring in choroidal neovascularizations and pigment epithelium detachment.
Conclusion
Electrophysiological responses indicated a general reduction in retinal function in all parts of the retina (not only in the macula but in every part of the retina) in ARMD.