97th DOG Annual Meeting 1999
MULTIFOCAL ELECTRORETINOGRAPHY IN AGE-RELATED MACULAR DEGENERATION - CHANGES IN IMPLICIT TIME OF THE 1st ORDER KERNEL
M. Weismann, B. Jurklies
To evaluate the effects of age-related macular degeneration (AMD) on the implicit time of evoked responses using multifocal electroretinography.
Methods: MERG was performed using the VERIS-System (EDI, San Francisco). The central 30º of the retina were stimulated concurrently and independently by 103 hexagons according to a pseudorandom m-sequence (Maximal luminance of 200 cd/sqm and 300 cd/sqm). Response components were extracted for each stimulated retinal location. Based on the findings of fluorescein angiography, 55 Patients with exudative AMD were divided into three groups: Group I (n=12) had classic, group II (n=37) had occult and group III (n=6) had both classic and occult choroidal neovascularization (CNV). Mean implicit times (1st order kernel) of groups with different eccentricity, from ring 1 (center) to ring 6 (periphery), were evaluated and compared to a normal control group. Normalized implicit times (IT) of the groups (ring 1-6) were compared to each other.
Results: In comparison to normal values, the IT were slightly prolonged in all of the three AMD groups. The changes in evoked responses were more evident in the central three groups than in the periphery of stimulated fields. Normalized IT of the central rings were affected more in group III than in groups I and II, respectively. The changes in IT were present under both luminance conditions.
Conclusions: IT (1st order kernel) were prolonged and were affected depending on the eccentricity and localization of CNV. However, there were only moderate changes in IT between the ARMD groups I and II.
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