Correlation Between Subfoveal Choroidal Thickness and the Severity or Progression of Nonexudative Age-Related Macular Degeneration

Abstract

To investigate the correlation between subfoveal choroidal thickness (SFChT) and the severity or progression of nonexudative AMD. One hundred seventy-six eyes of 114 patients with nonexudative AMD were included in this study. These eyes were divided into stages I through IV, based on the Age-Related Eye Disease Study (AREDS) classification of fundus findings. Using enhanced depth imaging from spectralis domain optical coherence tomography (SD-OCT), the central retinal thickness (CRT), SFChT, and parafoveal choroidal thickness (PFChT) were measured. The area of geographic atrophy (GA) was measured from fundus autofluorescence (FAF) images, and the progression of GA was calculated using RegionFinder software. The age-adjusted SFChT levels were lower at later stages of nonexudative AMD. These measurements were as follows: 266.68 ± 12.60 (stage I: 28 eyes), 263.34 ± 9.87 (stage II: 48 eyes), 200.55 ± 8.83 (stage III: 71 eyes), and 188.34 ± 13.72 (stage IV: 29 eyes) (P = 0.0028). The age-adjusted SFChT was also negatively correlated with the best corrected visual acuity (BCVA) (estimate, -0.001; P = 0.0006). Among 16 eyes with GA at baseline, SFChT showed a negative correlation with the baseline area of GA (r = 0.5521, P = 0.0133). In addition, GA progressed more rapidly during the mean follow up of 22.19 ± 9.08 months when the SFChT was lower at baseline (r = 0.5658, P = 0.0112). Subfoveal choroidal thickness is closely related to the BCVA, the severity of nonexudative AMD, as well as the rate of GA progression. Subfoveal choroidal thickness may be a predictor of disease progression in GA cases.