Decreased superficial retinal microvascular density in alopecia areata: an OCT angiography study

This study aimed to evaluate retinal microvascular and structural changes in patients with alopecia areata (AA) using optical coherence tomography angiography (OCTA). To our knowledge, retinal microvascular alterations have not been investigated via OCTA in AA before.

This prospective study included 40 patients with newly diagnosed AA and 42 healthy controls. Superficial capillary plexus vessel densities (VD-SCP) and deep capillary plexus vessel densities (VD-DCP), choriocapillaris flow area, foveal avascular zone (FAZ), retinal nerve fiber layer (RNFL) thickness, optic disc vascular parameters, and central corneal thickness (CCT) were measured.

VD-SCP was significantly reduced in the whole image (p = 0.001), parafoveal (p = 0.001), and perifoveal regions (p = 0.007) in patients with AA compared with controls. These differences remained significant after FDR correction (adjusted p = 0.011, 0.011, and 0.049, respectively). However, foveal VD-SCP did not differ significantly (p = 0.221). An unadjusted difference in inferior RNFL thickness (p = 0.044) did not remain statistically significant after FDR correction (adjusted p = 0.231), whereas global RNFL thickness showed no significant difference. No significant differences were observed between groups in VD-DCP, FAZ area, choriocapillaris flow, optic disc vascular parameters, foveal thickness, or CCT (all p > 0.05).

Patients with AA demonstrate reduced VD-SCP except in the foveal region, without evidence of widespread retinal or choroidal vascular impairment. These findings suggest that AA may be associated with early subclinical alterations in retinal microcirculation. OCTA may serve as a useful non-invasive tool for detecting subtle ocular microvascular changes in patients with AA.