Optical Coherence Tomography Angiography Assessment of Optic Nerve Head and Macula Across the Primary Angle Closure Disease Spectrum.

Prcis: The microvasculature of the optic disc and macula in eyes with acute primary angle closure and primary angle closure glaucoma was lower across the disease spectrum, but the significant difference was only observed in primary angle closure glaucoma.

Purpose: To assess the microvasculature in the optic nerve head (ONH) and macula across the primary angle closure disease (PACD) spectrum using optical coherence tomography angiography (OCTA).

Materials and methods: OCTA (AngioVue, Fremont, CA) imaging was performed on 122 PACD subjects. Flow area (FA) and vessel density (VD) in the ONH, radial peripapillary capillary (RPC) network, and superficial and deep capillary plexuses of the macula were calculated and compared across the PACD spectrum using linear regression models with generalized estimating equations adjusted for inter-eye correlation.

Results: A total of 234 eyes including 44 primary angle closure suspects (PACS), 93 primary angle closure (PAC), 79 primary angle closure glaucoma (PACG), and 18 PAC with a history of previous acute primary angle closure (APAC) were included in the analysis. Compared with other groups, PACG eyes showed smaller FA in the ONH (1.35±0.02 mm 2 ), RPC (0.78±0.03 mm 2 ), and the superficial retinal layer (1.08±0.03 mm 2 ) (all P <0.05). Lower VD was also observed in the "whole image," "inside disc," and "peripapillary" regions of the ONH and RPC, and the "whole image" and "parafoveal" regions of the retinal layer in the PACG group when compared with other groups (all P <0.05). No significant differences were found for the other groups (all P >0.05). Lower VD in the ONH, RPC, and superficial retinal layer significantly correlated with worse visual field loss in PACG eyes (all P <0.05).

Conclusions: Significant reduction in the microvasculature of the optic disc and macula in PACG suggests that glaucoma development may contribute to lower VD in these regions.