Abstract
Abstract: :
Purpose: Fluorescein Angiography (FA) and red-free fundus (RF) photography may reveal dissimilar patterns of retinal change in patients with age-related macular degeneration (AMD). This study compares the correlation between FA and RF findings to the first-order multifocal ERG (mfERG) responses in patients with large drusen. Methods: Twelve eyes of seven patients were evaluated. Inclusion criteria: age ≷ 55, visual acuity ≥ 20/63 (ETDRS), at least 5 drusen ≥ 63 microns in diameter within 2250 microns from the center of the fovea. Digital measurements of drusen (RF) and window defect and staining areas (late stage FA) were performed in 10 areas [ring of 1° (1), 1 - 5° (2), 5 - 10° (3), 10 - 15° (4) in radius, (3) and (4) divided into 4 sectors] using the area measurement tool (Ophthalmic Imaging System, Medivision). MfERG responses were recorded with the 7" stimulus-refractor unit (EDI) and VERISTM 4.3 using the following protocol: bipolar contact lens, m-sequence =14, 103 hexagons, consecutive stimulation with 200 (A) and 700 cd . m-2 (B) (contrast 99 %), pupils ≷ 6 mm, amplification 105, filter cut-off's at 10 and 300 Hz. Concentric ring mfERG responses were compared to age-matched values of 14 normal subjects (mean = 73 years). The first-order mfERG responses were analyzed for the same areas as used for FA and RF. Results: There were signficant correlations between log MAR and log latency N1 and log response density (RD) N1+P1 (peak to trough) for (B) only. The largest differences between patients with large drusen and normal controls were found for log latency P1 and N2. The percentage of abnormal retinal area was larger in RF than in FA. FA was better correlated to mfERG responses than RF. Correlations between FA and log latency N2 was more often correlated (7/10 areas) than FA and log RD N1+P1 (2/10) at 700 cd. m-2. Conclusion: The morphological changes in patients with large drusen revealed by FA, but not RF, are correlated with functional changes indexed by the mfERG response, particularly response latency.
Keywords: 391 drusen • 430 imaging/image analysis: clinical • 395 electroretinography: clinical