Identifying characteristic features of the retinal and choroidal vasculature in choroideremia using optical coherence tomography angiography

Purpose Using optical coherence tomography angiography (OCTA) to investigate the area with flow in the superficial retinal vessel network (SVRN) and choriocapillaris (CC) layer among male subjects with choroideremia (CHM), female carriers, and normal controls to identify vascular changes. Patients and methods Images of SRVN and CC layer were acquired in 9 affected males, 5 female carriers, and 14 age- and gender-matched controls using the Angiovue software of the RTVue XR Avanti. Results The mean age was 33 years for affected male CHM patients (median 30 years), 46 years for female carriers (median 53 years), and 39 years for controls (median 38.5). Mean SRVN area +/- SD in subjects with CHM was 12.93 +/- 2.06 mm(2), in carrier subjects 15.36 +/- 0.60 mm(2), and in controls 15.30 +/- 1.35 mm(2) (P<0.01). The mean CC area +/- SD with flow was 6.97 +/- 5.26 mm(2) in CHM subjects, 21.65 +/- 0.17 mm(2) in carriers and 21.36 +/- 0.76 mm(2) in controls (P<0.01). SRVN and CC area with flow showed a negative correlation in CHM subjects with the age (r=-0.86; P<0.003 and r=-0.77; P<0.01, respectively). CC area with flow had a positive correlation with SRVN (r=0.83, P<0.001). Overall, visual acuity had a negative correlation with SRVN and CC area with flow (r=-0.67, P<0.001 and r=-0.57, P<0.002, respectively). Conclusions: This is the first study to highlight changes in the SRVN in CHM subjects. OCTA detected a reduced area with flow in both retinal and choroidal circulations, and may be a useful tool for monitoring natural history and disease progression in forthcoming clinical trials.