Peripapillary retinal vessel density in eyes with acute primary angle closure: an optical coherence tomography angiography study

Purpose The purpose was to investigate peripapillary retinal vessel density in resolved acute primary angle closure (APAC) eyes. Methods This was a prospective, cross-sectional observational study. Thirty-four eyes of 34 patients with unilateral APAC were included, together with the fellow eyes with primary angle closure suspect (PACS) as controls. Peripapillary retinal vessel density was measured using optical coherence tomography (OCT) angiography. Peripapillary retinal vessel density was compared in both eyes and the potential relationship with visual field (VF) test results was evaluated. Results After an acute attack, the peripapillary retinal vessel density was lower in the APAC than in the PACS eyes (79.3 +/- 8.2 versus 85.6 +/- 4.9, respectively; P = 0.001). The VF mean deviation (MD) (-7.7 +/- 6.7 versus -3.3 +/- 1.8 dB, P = 0.002), and the pattern standard deviation (PSD) (4.6 +/- 3.3 versus 2.4 +/- 0.9 dB, P = 0.001) were worse for the APAC than the PACS eyes, but both had similar thicknesses of the retinal nerve fiber layer (RNFL) (111.8 +/- 9.6 versus 114.1 +/- 29.1 mu m, P = 0.880) and ganglion cell complex (GCC) (94.7 +/- 7.5 versus 91.8 +/- 9.3 mu m, P = 0.328). The peripapillary retinal vessel density was significantly correlated with the VF MD (vessel density: r = 0.455, P = 0.008) and PSD (vessel density: r = -0.592, P < 0.001) in the APAC eyes. Conclusions Even when IOP was normalized after the acute attack, the APAC eyes had a lower peripapillary retinal vessel density, which was correlated with the VF values. OCT angiography is a reliable method for detecting vascular changes in glaucomatous eyes that show no thinning of the RNFL and GCC.