LONGITUDINAL ANALYSIS OF MICROVASCULAR CHANGES IN SICKLE CELL DISEASE USING SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

Abstract

To analyze the changes in macular vascular densities (VDs) and foveal avascular zone (FAZ) over a 6-year period using swept-source optical coherence tomography angiography in patients with sickle cell disease compared with unaffected control subjects. Thirty eyes of patients with sickle cell disease and 12 eyes of unaffected control subjects matched for age and ethnicity were examined at a 6-year interval using the same imaging protocol, including ultra-wide-field angiography, swept-source OCT, and 3 × 3-mm optical coherence tomography angiography. The macular VD and FAZ were measured on ImageJ software according to previously reported algorithms. In sickle cell eyes, the mean FAZ significantly increased ( P < 0.01), and the VD decreased in the foveal (within a circle of 1.5 mm in diameter around the foveal center) and temporal areas in both the superficial and the deep capillary plexuses ( P < 0.01). The VD did not change over time in the parafoveal area (annulus between two circles of 1.5 and 3 mm in diameter) and in the superior, inferior, and nasal sectors. No worsening of peripheral retinopathy was observed in the cohort during the follow-up, except for one eye that developed sea-fan. In the control eyes, no microvascular change was observed over time in FAZ size and VD. These longitudinal optical coherence tomography angiography findings in patients with sickle cell disease showed an enlargement of the FAZ and a decrease in VD in the temporal and perifoveal regions despite the absence of progression of peripheral retinopathy, suggesting a worsening of the macular nonperfusion over time in sickle cell disease.