Relationship between the vessel density around the optic nerve head and visual field deterioration in eyes with retinitis pigmentosa

To analyze the vessel density around the optic nerve head (ONH) by optical coherence tomography angiography (OCTA) in patients with retinitis pigmentosa (RP), and to evaluate its correlation with visual functions. Thirty-eight eyes with RP with visual field constriction within the central 10° were enrolled. The mean (± SD) age of the patients was 43.7 ± 15.1 years. In addition to visual acuity (VA) measurements and visual field tests (Humphrey Field Analyzer 10–2 test), we also measured the vessel density at the macula by OCTA (superficial and deep vessel density: sVD(m) and dVD(m)) and in multiple layers around the ONH (vessel density in the radial peripapillary capillary [RPC] layer and in the nerve head [NH] layer: VDrpc and VDnh). The vessel density was calculated by binarizing the OCTA images. The associations between the logMAR VA and mean deviation (MD) values and the variables of central retinal thickness (CRT), sVD(m), dVD(m), VDrpc, VDnh, and also the size of the foveal avascular zone were investigated. The mean logMAR VA was 0.16 ± 0.34 and the MD value was − 17.2 ± 10.3 dB; the MD value was significantly related to the logMAR VA (p = 0.0028). Multivariate analysis with AICc model selection suggested only dVD(m) was associated with logMAR VA. On the other hand, the optimal model for the MD value included the CRT, dVD(m), and VDnh. The vessel density in the deep layer around the ONH was significantly associated with the visual field deterioration in patients with RP.