Abstract
Purpose :
To describe pathologic flow loss in the choriocapillaris detected with SS-OCTA in patients with BSCR
Methods :
Cross sectional observational study. BSCR patients underwent comprehensive ophthalmic examinations and SS-OCTA imaging [DRI OCT Triton, Topcon, Tokyo]. Each eye was imaged 3 times: 3x3mm image centered on the fovea, 6x6mm image centered on the fovea and 12x12mm image that captured both the macula and optic disc. The OCTA images were evaluated by a retina specialist for pathologic flow loss in the choriocapillaris. The choriocapillaris vascular density (CVD) at the foveal central subfield, defined as the central 1mm diameter circle in the Early Treatment Diabetic Retinopathy Study (ETDRS) grid, for each eye was calculated using a proprietary, automatic algorithm.
Results :
39 eyes from 21 patients are included in the study. The mean age is 62.5 ± 8.3 years. The mean LogMAR visual acuity (VA) is 0.18 ± 0.26 (mean Snellen VA 20/30, range 20/15 to 20/200). Two patterns of pathologic choriocapillaris flow floss are observed: patchy non-confluent (66.7% of eyes) and discrete well-circumscribed (46.2% of eyes). In total, 31/39 (79.5%) eyes have some degree of pathologic flow loss. Of the 14 eyes (in 10 patients) with VA 20/20 or better, pathologic flow loss is seen in 10 eyes (71.4%). The foveal CVD is available in 32/39 (82.1%) eyes. The range of foveal CVD in eyes with normal vision is 46.3% to 58.2%. The mean foveal CVD in eyes with VA 20/20 or better is 52.5% ± 4.0%, while the mean foveal CVD in eyes with VA 20/30 or worse is 47.5% ± 3.6% (two-sided p-value 0.005).
Conclusions :
Although BSCR predominantly affects the choroid and retina peripheral to the major vascular arcades, pathologic flow loss in the choriocapillaris is frequently encountered in the macula. Even in eyes with normal VA, there is pathologic flow loss in >50% of eyes. This may explain the previously published observations that BSCR eyes with normal vision frequently have decreased contrast sensitivity and that inactive BSCR eyes have decreased sensitivities on microperimetry when compared to controls. BSCR eyes with abnormal vision, on average, have lower foveal CVD as compared to eyes with normal vision, suggesting that pathological flow in the choriocapillaris may contribute to decreased VA in BSCR eyes.
This is a 2020 ARVO Annual Meeting abstract.