Vessel Density and Structural Measurements of Optical Coherence Tomography in Primary Angle Closure and Primary Angle Closure Glaucoma

Abstract

Purpose: To evaluate the vessel density measurements of the optic nerve head (ONH), peripapillary, and macular regions on optical coherence tomography (OCT) angiography in eyes with primary angle closure (PAC) and primary angle closure glaucoma (PACG), and to compare their diagnostic abilities with the ONH rim area, peripapillary retinal nerve fiber layer (RNFL) thickness, and the macular ganglion cell complex (GCC) thickness measurements on OCT in PACG.

Design: Cross-sectional study.

Methods: Seventy-seven eyes of 50 control subjects, 65 eyes of 45 patients with PACG, and 31 eyes of 22 PAC patients with a history of high intraocular pressure underwent imaging with OCT. Area under receiver operating characteristic curves (AUC) and sensitivities at fixed specificities of vessel densities were compared with structural measurements.

Results: All the vessel density and structural measurements were significantly lower (P < .05) in the PACG compared with the control group. Vessel densities in the PAC were similar (P > .05) to that of the controls; the superotemporal RNFL, however, was significantly thinner in the PAC group (127 μm vs 135 μm, P = .01). The AUC and sensitivity at 95% specificity of vessel densities within the ONH (0.76 and 42%) and macular region (0.69 and 18%) in PACG were significantly lower P < .001) than ONH rim area (0.90 and 77%) and GCC thickness (0.91 and 55%), respectively. AUC and sensitivity of peripapillary vessel density (0.85 and 53%) were similar (P = 0.25) to RNFL thickness (0.91 and 65%).

Conclusions: These results suggest that structural changes in PACG occur earlier than the reduction in retinal vessel densities.