PURPOSE

To determine the prevalence and factors associated with the presence of choroidal microvascular dropout (CMvD) in primary angle-closure glaucoma (PACG) eyes compared to primary open-angle glaucoma (POAG) eyes.

DESIGN

Cross-sectional study.

METHODS

Thirty-six POAG eyes (36 patients) and 28 PACG eyes (28 patients) underwent optical coherence tomography angiography (OCTA). Presence of CMvD was evaluated on choroidal OCTA slabs. Visual field (VF) defects in the glaucoma eyes were classified into initial nasal defect (IND), initial parafoveal scotoma (IPFS), and combined nasal and parafoveal defect, and the association between type of VF defect and CMvD was evaluated.

RESULTS

CMvD was detected in 21 POAG (58.3%) and 10 PACG (35.7%) eyes (P = .07). CMvD in POAG eyes was associated with pretreatment intraocular pressure (odds ratio [OR] = 0.91/mm Hg higher intraocular pressure, P = .06), VF mean deviation (MD, OR = 0.75/dB higher MD, P = .007), retinal nerve fiber layer thickness (OR = 0.92/μm increase in thickness, P = .02), and peripapillary vessel density (OR = 0.80/unit increase in density, P = .01). CMvD in PACG eyes was associated only with VF MD (OR = 0.90/dB higher MD, P = .05). When analyzed in the entire cohort of glaucoma patients (64 eyes), CMvD was significantly associated with POAG (OR > 3.5, P < .05) after accounting for glaucoma severity. CMvD was seen in 6 of 7 eyes with IPFS and 1 of 13 with IND in the POAG group (P < .05) and 1 of 2 eyes with IPFS and 0 of 10 with IND in the PACG group (P < .05).

CONCLUSIONS

Prevalence of CMvD was significantly lower in PACG compared to POAG. As in POAG, CMvD in PACG was associated with advanced VF damage and with IPFS on VF.