Correlation between Topographic Progression of Geographic Atrophy and Visual Acuity Changes

Purpose: To analyze topographic progression of geographic atrophy with different concentric circles centered on the fovea incorrelation with decrease of visual acuity. Methods: We retrospectively analyzed 36 eyes of 26 patients diagnosed with geographic atrophy and followed at least1 year. One millimeter circular area at the foveal center were defined as zone 1, and doughnut shape areas from between1 and 2 mm to between 5 and 6 mm were defined as zone 2 to 6. Then, changes of geographic atrophy area in each zonewere measured with semi-automatic software. Correlation analysis and regression analysis were performed to determine therelationship between changes in visual acuity and atrophic area in each zone. Results: Mean age was 76.9 years and follow-up period were 3.38 years. The mean atrophic area increased from 8.09 to16.34 mm2 and visual acuity decreased from 0.39 to 0.69 on logarithm of the minimal angle of resolution. Mean change oftotal geographic atrophy area was not significantly correlated with visual acuity decrease. While geographic atrophy progressionwithin zone 1, 2, and 3 showed significant causal relationship with decrease of visual acuity (all, p < 0.05). Conclusions: In contrast to the total geographic atrophy area, progression of geographic atrophy in parafoveal area wassignificantly correlated with decrease of visual acuity.