Purpose: To assess foveal and parafoveal vasculature at superficial capillary plexus (SCP), deep capillary plexus, and choriocapillaris using optical coherence tomography angiography in the fellow eyes of patients with Coats disease.
Methods: Observational and prospective case series. Thirteen patients with unilateral Coats and 14 healthy age- and sex-matched controls were consecutively recruited at Manchester Royal Eye Hospital and the Department of Ophthalmology of San Raffaele Hospital. Both groups underwent complete ophthalmologic examination, including optical coherence tomography angiography (Topcon Corp) 3 mm × 3 mm scans. Images were imported into ImageJ software and binarized; foveal avascular zone area was manually outlined and vessel density analyzed in inner (foveal) and outer (parafoveal) areas of SCP, deep capillary plexus, and choriocapillaris.
Results: Fellow eyes disclosed a significant increase in the foveal vessel density of SCP (P = 0.04); in particular, superior and temporal quadrants showed more marked alterations (P = 0.02 and 0.04, respectively). Analysis of foveal avascular zone area revealed a significant enlargement in the SCP (P = 0.04). No correlation was found between fellow eyes and the stage of affected eyes.
Conclusion: Fellow eyes of Coats patients carry quantitative foveal vascular alterations at SCP. These may represent markers of altered inner blood-retinal barrier, due to a bilateral defect in midcapillary angiogenesis.