Retinal Sensitivity and Fundus Autofluorescence in Intermediate Age related Macular Degeneration.
Purpose: To evaluate fixation stability and retinal sensitivity in the central 10º in Intermediate Age-Related Macular Degeneration (AMD), correlating these values with focal retinal changes on retinography and fundus autofluorescence (FAF).
Methods: A cross-sectional observational study enrolling patients with intermediate AMD, analyzed concerning microperimetric macular sensitivity (MP3 Microperimeter, Nidek®, Inc.), color retinography and FAF (Topcon® DRI OCT). Other variables considered were best corrected visual acuity (BCVA), fixation stability and FAF pattern.
Results: This study evaluated 33 eyes of 18 patients with mean age of 75,55±6,14, and a mean BCVA of 71±9,1 letters (modified EDTRS grid). Mean retinal sensitivity was 21,9±5,04dB, and mean bivariate contour ellipse area (BCEA) 99,6% was 13,61±9,51º2, with 30,3% of eyes showing relatively unstable fixation. Concerning the individual analysis of macular points (N=561), we identified a greater decrease in retinal sensitivity in points of decreased FAF (17±8,3dB) and increased FAF (13,06±6dB) comparing with normal FAF (9,6±4,6dB) (p<0.001).
Conclusions: Changes in FAF seem to be closely related to decreased focal retinal sensitivity. BCVA may be insufficient as a retinal function evaluation tool in intermediate AMD, with most patients showing altered fixation stability and multiple focal changes in retinal sensitivity in the central 10º. Microperimetry could become a valuable tool in functional follow-up of these patients, in correlation with FAF as a structural evaluation exam.