Clinical Characteristics and Progression of Pachychoroid and Conventional Geographic Atrophy

Abstract

Purpose: To elucidate the clinical characteristics and progression rates of pachychoroid and conventional geographic atrophy (GA).

Design: Retrospective, multicenter, observational study.

Participants: A total of 173 eyes from 173 patients (38 eyes with pachychoroid GA and 135 with conventional GA) from 6 university hospitals in Japan were included. All patients were Japanese, aged ≥50 years and with fundus autofluorescence images having analyzable image quality. A total of 101 eyes (22 with pachychoroid GA and 79 with conventional GA) were included in the follow-up group.

Methods: The studied eyes were classified as having pachychoroid or conventional GA; the former was diagnosed if the eye had features of pachychoroid and no drusen. The GA area was semiautomatically measured on fundus autofluorescence images, and the GA progression rate was calculated for the follow-up group. Multivariable linear regression analysis was used to determine whether the rate of GA progression was associated with GA subtype.

Main outcome measures: Clinical characteristics and progression rates of pachychoroid and conventional GA.

Results: The pachychoroid GA group was significantly younger (70.3 vs. 78.7 years; P < 0.001), more male-dominant (89.5 vs. 55.6%; P < 0.001), and had better best-corrected visual acuity (0.15 vs. 0.40 in logarithm of the minimum angle of resolution; P = 0.002), thicker choroid (312.4 vs. 161.6 μm; P < 0.001), higher rate of unifocal GA type (94.7 vs. 49.6%; P < 0.001), and smaller GA area (0.59 vs. 3.76 mm^2;P < 0.001) than the conventional GA group. In the follow-up group, the mean GA progression rate (square-root transformation) was significantly lower in the pachychoroid GA group than in the conventional GA group (0.11 vs. 0.27 mm/year; P < 0.001).

Conclusions: Demographic and ocular characteristics differed between GA subtypes. The progression rate of pachychoroid GA, adjusted for age and baseline GA area, was significantly lower than that of conventional GA. Japanese patients with conventional GA showed characteristics and progression rates similar to those in White populations. Some characteristics of GA in Japanese population differ from those in Waucasian populations, which may be due to the inclusion of pachychoroid GA.

Financial disclosures: 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; Pachychoroid geographic atrophy; Subtype.

Figure 1

Multimodal imaging of pachychoroid GA in a 63-year-old man (A–C), conventional GA in a 74-year-old man (D–F) and bilateral pachychoroid GA in an 81-year-old man (G–L). A, D, G, J, Color fundus photography. B, E, H, K, Fundus autofluorescence images. C, I, Enhanced depth imaging OCT. F, L, Spectral domain OCT. Yellow arrows indicate the scan lines of OCT images, that show complete retinal pigment epithelium and outer retinal atrophy. Dilated outer choroidal vessels are seen in pachychoroid GA cases (C, I and L). Subfoveal choroidal thickness is 370 (C), 84 (F), 259 (I), and 287 μm (L), respectively. GA = geographic atrophy.

Figure 2

Progression of pachychoroid GA in a 70-year-old man with 73 months’ follow-up (A, C and E), and an 86-year-old man with 42 months’ follow-up (B, D and F), alongside that of conventional GA in an 83-year-old man with 92 months’ follow-up (G, I) and an 87-year-old woman with 73 months’ follow-up (H, J). A, B, G, H, Fundus autofluorescence images. Yellow arrows indicate the scan lines of OCT on panels C, D, I and J. Yellow dotted arrows indicate the scan lines of OCT through the GA lesion on panels E and F. Enhanced depth imaging OCT shows dilated outer choroidal vessels (C, D). Spectral-domain OCT images demonstrate complete outer retinal atrophy (E, F, I and J). In all cases, the GA area increased from baseline to the final visit. The GA progression rate (square-root transformation; SQRT) was 0.07 (A), 0.07 (B), 0.16 (G), and 0.33 mm per year (H), respectively. GA = geographic atrophy.

Figure 3

Scatter plot showing the association between baseline GA area (SQRT) and GA progression rate (SQRT) in the follow-up group. The red dots show the cases of pachychoroid GA; the blue dots show the cases of conventional GA. The straight lines are the regression lines of the 2 groups (pachychoroid GA group; Y = 0.085 + 0.031 × X, conventional GA group, Y = 0.169 + 0.065 × X). GA = geographic atrophy; sqrt = square-root transformation.