Structural and vascular features of the retina and choroid with retinitis pigmentosa imaged using ultra-widefield swept-source optical coherence tomography angiography.

PURPOSE: Information from optical coherence tomography angiography (OCTA) on the pathogenesis of retinitis pigmentosa (RP) is limited to the posterior pole; however, pathological changes begin at the peripheral pole. Therefore, we imaged eyes diagnosed with RP using ultra-widefield swept-source (UWF SS)-OCTA.

METHODS: We retrospectively analyzed patients with RP and age-matched controls who underwent fovea-centered UWF SS-OCTA imaging.

RESULTS: We examined 63 RP eyes and 40 healthy eyes. RP eyes had thinner outer retinal and choroidal thicknesses (p ≤ 0.01), greater inner retinal thickness and retinal nerve fiber layer (p < 0.01), decreased superficial capillary plexus (SCP) area throughout the retina, and larger foveal avascular zone area (p < 0.01) than healthy eyes. SCP microvessel density, deep capillary plexus, and choroidal capillary plexus were markedly decreased in RP eyes (p < 0.01). SCP area and density were positively correlated at a diameter of 6 mm and SCP vessel density and inner retinal thickness were strongly negatively correlated at a diameter of 3 mm (p = 0.01). Further, outer retinal thickness was significantly correlated with choroidal thickness (p < 0.05).

CONCLUSION: UWF-SS-OCTA, enabling the visualization of the peripheral fundus area, is useful in quantifying structural and vascular parameters of the central and peripheral retinal and choroidal layers in RP eyes, and can aid in elucidating the pathophysiology and monitoring disease progression.