Assessment of Choriocapillaris in Healthy and Diseased Eyes Using 3-Dimensional Topographic Maps Based on OCT Angiography.

Purpose: To achieve clear in vivo imaging and systematic quantification of choriocapillaris (CC), enabling the exploration of age-related and disease-related changes of CC within a large sample size. Design: Cross-sectional study. Participants: A total of 1050 eyes from 727 individuals, comprising 633 healthy eyes, 277 eyes with age-related macular degeneration (AMD), and 140 eyes with high myopia. Methods: The 3-dimensional (3D) topographic maps of CC were obtained by performing image enhancement, depth reconstruction, and 3D rendering on a single OCT angiography enface image. Based on this map, we targeted key quantitative parameters to analyze vessel thickness, vascular complexity, vascular distribution uniformity, and blood perfusion of CC. We statistically analyzed the correlation between CC metrics and age in healthy population, as well as differences in CC metrics between healthy and diseased populations. To further explore the association between changes in CC and choroidal large vessels, we defined a parameter called "arterial zone (AZ) to venous zone (VZ) ratio" to assess the choroidal large-vessel perfusion. Main Outcome Measures: The 3D topographic map of CC, 8 parameters of CC, and AZ/VZ. Results: The 3D topographic map effectively displayed the morphology of CC while maintaining high image accuracy. Statistical analysis revealed that with aging, the vessel thickness of CC in healthy eyes became thicker, and there was a decrease in vascular complexity, distribution uniformity, and perfusion. Additionally, AZ/VZ exhibited a trend of initial decline followed by an increase. In eyes with increasing severity of AMD, the vessel thickness of CC showed bidirectional changes followed by significant thickening. Complexity and distribution uniformity initially increased, followed by a marked decrease, whereas blood perfusion decreased initially before increasing. However, no significant intergroup differences in AZ/VZ were observed. In highly myopic eyes, compared to healthy eyes, the CC exhibited vessel thickening, reduced complexity and distribution uniformity, decreased perfusion, and a significant reduction in AZ/VZ. Conclusions: This study explores age-related and disease-related CC changes via clear in vivo imaging and quantification. It aids understanding of CC states and may contribute to early disease diagnosis and prognosis. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.