Clinical Characteristics and Progression of Geographic Atrophy in a Japanese Population

Abstract

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 6 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 1 eye.

Methods: The GA area was measured semiautomatically using fundus autofluorescence (FAF) images. In the follow-up group followed for > 6 months with FAF images, the GA progression rate was calculated by 2 methods: mm² per year and mm per 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 (42.2%) eyes, 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 per year (0.23 ± 0.18 mm/year [SQRT]). In the multivariable analysis, the 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 White populations. Asian patients with GA showed male dominance and relatively thicker choroid than White 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 White populations. Large GA and reticular pseudodrusen were associated with a greater GA progression rate.

Financial disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Keywords: Age-related macular degeneration; Geographic atrophy; Japanese; Reticular pseudodrusen; Square-root transformation.