To determine whether the frequency of parafoveal visual field (VF) damage differs according to the presence of choroidal microvasculature dropout (CMvD) in open-angle glaucoma (OAG) and to assess correlations between the angular circumference of CMvD and the severity of VF defects.

Retrospective case-control study.

This study enrolled 88 eyes of 88 consecutive OAG patients (44 with CMvD and 44 without CMvD matched for age [≤5 years], axial length [≤1 mm], and the severity of VF loss [≤1 dB]). Angular circumference of CMvD was determined from choroidal layer images obtained from optical coherence tomography angiography. Demographic and ocular characteristics, including the presence of parafoveal VF defects and VF mean sensitivity (MS), were compared between OAG eyes with CMvD and those without. Logistic regression analyses were performed to derive the clinical factors associated with parafoveal VF defects. The relationships between CMvD angular circumference and global/regional VF defect severity were assessed.

Parafoveal VF defects were observed in 96% (42/44) of eyes with CMvD but only in 39% (17/44) of eyes without CMvD. OAG eyes with CMvD showed significantly lower superior parafoveal VF MS compared to those without. A significant association was found between parafoveal VF defects and CMvD in OAG eyes, and CMvD angular circumference was significantly correlated with the severity of VF defects.

The involvement of parafoveal VF defects was significantly associated with the presence of CMvD. Among eyes with CMvD, CMvD angular circumference had significant correlations with the severity of VF defects.