Clinical Characteristics and Progression of Geographic Atrophy in a Japanese Population.

PURPOSE: To elucidate the clinical characteristics and progression rate of geographic atrophy (GA) associated with age-related macular degeneration (AMD) in a Japanese population.

DESIGN: Retrospective, multicenter, observational study.

PARTICIPANTS: A total of 173 eyes from 173 patients from six university hospitals in Japan were included. Of 173 study eyes, 101 eyes from 101 patients were included in the follow-up group. All patients were Japanese, aged ≥ 50 years, and had definite GA associated with AMD in at least one eye.

METHODS: The GA area was measured semi-automatically using fundus autofluorescence (FAF) images. In the follow-up group followed for more than six months with FAF images, the GA progression rate was calculated by two methods: mm2 /year and mm/year using the square-root transformation (SQRT) strategy. Simple and multiple linear regression analyses were used to identify the baseline factors associated with the GA progression rate.

MAIN OUTCOME MEASURES: Clinical characteristics of GA and the GA progression rate.

RESULTS: The mean age was 76.8 ± 8.8 years and 109 (63.0%) were males. Sixty-two (35.8%) patients had bilateral GA. The mean GA area was 3.06 ± 4.00 mm2 (1.44 ± 1.00 mm [SQRT]). Thirty-eight eyes (22.0%) were classified as having pachychoroid GA. Drusen and reticular pseudodrusen were detected in 115 (66.5%) and 73 eyes (42.2%), respectively. The mean subfoveal choroidal thickness was 194.7 ± 105.5 μm. In the follow-up group (follow-up period: 46.2 ± 28.9 months), the mean GA progression rate was 1.01 ± 1.09 mm2 /year (0.23 ± 0.18 mm/year [SQRT]). In the multivariable analysis, baseline GA area [SQRT] (P=0.002) and the presence of reticular pseudodrusen (P<0.001) were significantly associated with a greater GA progression rate [SQRT].

CONCLUSIONS: Certain clinical characteristics of GA in Asian populations may differ from those in Caucasians. Asian patients with GA showed male-dominance and relatively thicker choroid than Caucasian patients. There was a group with GA without drusen but with features of pachychoroid. The GA progression rate in this Asian population was relatively lower than that in Caucasians. Large GA and reticular pseudodrusen were associated with a greater GA progression rate.