Optical Coherence Tomography Angiography (OCT-A) in young choroideremia (CHM) patients

Purpose: To study OCT-A findings in young patients affected with CHM Methods: Young patients affected with CHM and age-matched control subjects were consecutively enrolled at the Regional Reference Center for Hereditary Retinal Degenerations at the Eye Clinic in Florence. All patients underwent a complete ophthalmic examination including best-corrected visual acuity (BCVA), fundus autofluorescence (FA), optical coherence tomography (SS-OCT) and 3 × 3 mm swept-source OCT angiography (SS-OCTA). Superficial capillary plexus (SCP), deep capillary plexus (DCP) and OCT-A choriocapillaris slabs (CC) were processed using Imagej software to identify vessel density (VD). Results: Seven patients affected with CHM (14 eyes) and 7 age - matched control subjects (14 eyes) were included in our study. Visual acuity was 20/20 in all subjects. The detected CRT was significantly lower in the control group (212 ± 8,01 µm) in comparison with the patients (234 ± 53,7 µm), p < 0.01. The CC VD was reduced compared to controls (p < 0.01). Quantitative analysis of the inner retinal vasculature disclosed a significant impairment of both SCP (P < 0.01) and DCP (p < 0.01) vessel density compared to the control group. The FAZ area of the patients was smaller than controls (p < 0.01). Conclusion: OCT-A examinations revealed early vascular abnormalities in both inner retinal layers and choriocapillaris. A reduced vascular flow was also detectable in the presence of a preserved macular RPE at the color fundus, FA, and OCT examinations. OCT-A is clinically useful for evaluating early involvement of the retinal and choriocapillaris vascular network in choroideremia.