Abstract
Purpose :
The inner choroid (i.e., choriocapillaris) is known to be affected in eyes with geographic atrophy (GA) secondary to age-related degeneration (AMD). However, evaluations of the outer and larger choroidal vessels are rare. The aim of this study is to longitudinally quantitate regional changes in the larger choroidal vessels of patients with GA, using optical coherence tomography (OCT).
Methods :
In this IRB-approved retrospective analysis, we collected data from 23 eyes with GA from 23 patients who had structural OCT images obtained with enhanced depth imaging (EDI). To investigate longitudinal changes in larger choroidal vessels, subjects had 3 OCT scans spaced 6 months apart from one another, spanning a cumulative period of 1 year. Using imageJ, quantitative analysis was performed in 3 regions: (i) GA region, (ii) 150-μm-wide ring around the GA, and (iii) GA-free region. In the GA region we chose all visible vessels (more than one) identifiable. Within the ring around the GA border, the first visible vessel moving from the GA region outward was selected and measured. In the GA-free region the first visible vessel from the external margin of the ring was identified and analyzed. Overall, 76 choroidal vessels were identified at baseline and traced through the follow-ups. For each vessel, the area and the horizontal and vertical diameters were measured at each visit (unit of measurement was µm2 and µm, respectively). P values were obtained with the related-samples Friedman’s Two-Way Analysis of Variance.
Results :
Mean±SD age was 74.2±6.5 years. In the GA region, the vessel area had a significant reduction over time (4269.5±2675.7 at baseline, 3664.6±2165.4 at the 6-month visit, and 3346.9±2004.9 at the 12-month visit; p<0.001). Similarly, there was a notable longitudinal decrease observed in both the horizontal and vertical diameters (p=0.003 and p=0.009, respectively). By contrast, both the ring around the GA border and the GA-free region did not show significant changes in choroidal measurements over time.
Conclusions :
Similar to the choriocapillaris, the outer and larger choroidal vessels appear to abruptly contract within the area of GA. This may suggest that these vessels are under a very tight paracrine control. Additional investigations are necessary to unravel the biological mechanisms governing the deeper vessels, potentially utilizing them as biomarkers and factors influencing the progression of GA.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.