Clinical Characteristics of Geographic Atrophy Differ Between White and Asian Individuals

Clinical characteristics of geographic atrophy (GA), including choroidal thickness, drusen and pachychoroid presence, and GA progression rate, may differ between Asian and White populations, according to findings published in Ophthalmology Retina. Researchers conducted a retrospective, multicenter study to elucidate the clinical characteristics and progression rate of GA associated with age-related macular degeneration (AMD) in a Japanese population.

The study included 173 eyes from 173 patients (aged ≥50 years) of Japanese ethnicity. The followup group included 101 eyes (mean followup time, 46.2 months). All participants had definite GA associated with AMD in at least 1 eye. Clinical characteristics of geographic atrophy in patients with White ethnicities were derived from prior published research.

The study authors report that the clinical characteristics of geographic atrophy for those in the study included Pachychoroid GA (22.0%), bilateral GA (35.8%), and a mean GA area of 3.06±4.00 mm². 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. The mean GA progression rate was 1.01±1.09 mm²/year in the follow-up group. Baseline GA area (P =.002) and the presence of reticular pseudodrusen (P <.001) were significantly associated with a greater GA progression rate in the multivariable analysis.

By comparison, previous research shows mean area of GA for patients with White ethnicities are larger at 4.62 to 6.00 mm². However, mean subfoveal choroidal thickness was larger in Asian patients than White patients (151–173.0 µm). Prior research also shows White patients progression rates were approximately 1.27–1.43 mm²/year).

The study notes that the prevalence of GA is currently low in Asian countries, but that the population is rapidly aging, suggesting greater urgency for data on the clinical characteristics of geographic atrophy.

“Researchers need to consider the differences in phenotype of GA in different ethnicities as these differences may have implications when researching GA and considering interventions to slow progression of GA,” according to the study authors.

Disclosure: Multiple study authors declared affiliations with the biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.