Significant Reduction in Perforating Scleral Vessels of Glaucomatous Eyes Detected by Deep-Learning assisted Optical Coherence Tomographic Images

Abstract

Purpose : The relationship between the number of branching short posterior ciliary arteries (SPCAs) and glaucoma prevalence is unclear. Our retrospective, observational clinical study aimed to determine whether glaucoma patients exhibit fewer branching SPCAs compared to non-glaucomatous individuals. We utilized enface swept-source optical coherence tomography (SSOCT) enhanced with deep learning (DL) algorithms to quantify the SPCAs crossing from the sclera into the choroid.

Methods : The current study included 22 eyes of 22 consecutive patients with glaucoma who underwent SSOCT imaging between October 2017 and January 2019 at the Department of Ophthalmology, Osaka University Hospital. Twenty-three eyes of 13 age-matched healthy control patients were also recruited. The enface images of 6 x 6-mm² peripapillary area were created from SSOCT volume scans with a DL-based image enhancement. Two retinal specialists and two young ophthalmologists independently counted the number of perforating scleral vessels by scrolling enface images and the average number of the four was used for the analysis. Two-tailed Student's t-test was used for statistical analysis.

Results : In glaucoma subjects, 6 were males and 16 were females. Mean age was 51.7 ± 12.7 years, mean refractive error (RE) was -2.5 ± 1.8 D, and axial length (AL) was 24.8 ± 0.86 mm. In control subjects, all were females, mean age was 50.0 ± 6.2 years, mean RE was -1.1 ± 1.4 D, and mean AL was 23.6 ± 1.08 mm. The number of scleral perforators was significantly decreased in the glaucoma group compared to the control group (P<0.0001). The ROC curve had an AUC of 0.98, and when the cutoff value was set as 22.13, the sensitivity for glaucoma was 91.7% and the specificity was 95.7%. There was no significant difference in the number of perforators between elderly and young glaucoma patients (P=0.88).

Conclusions : This pioneering investigation reveals that glaucomatous eyes possess a significantly reduced number of scleral perforators relative to controls, independent of age. This may indicate that fewer scleral vessels could signal an inherent risk for glaucoma, associated with localized retinal capillary perfusion deficits from an early stage. These novel findings necessitate further research to decode the vascular role in glaucoma pathophysiology.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.