Choroidal Microvasculature Dropout Is Associated with Progressive Retinal Nerve Fiber Layer Thinning in Glaucoma with Disc Hemorrhage

Objective: We used OCT angiography (OCT-A) to investigate parapapillary choroidal microvasculature dropout (MvD) in glaucomatous eyes with or without disc hemorrhage (DH), and the association with changes in retinal nerve fiber layer (RNFL) thickness. Design: An observational case-control study. Participants: Eighty-two open-angle glaucoma (OAG) eyes with DH and 68 OAG eyes without DH that underwent at least 4 serial OCT examinations were included. Methods: MvD was defined as complete loss of microvasculature within the choroidal layer of the parapapillary region, as revealed by standardized assessment of OCTA-derived density maps of the vessels of the optic nerve head. The circumferential extent of MvD was measured on OCT-A images. The RNFL thinning rate was calculated using a linear mixed model. Kaplan-Meier survival analysis and the log-rank test were used to compare the cumulative risk ratio of progression between groups stratified by DH and MvD. Main Outcome Measures: MvD detection rate, the extent of MvD as measured by the MvD angle, and RNFL thinning rate. Results: MvD was found in 38 (46.3%) eyes with DH at the prior DH site, which was found in only 20 (29.4%) eyes without DH, which was significantly different between the 2 groups (P = 0.025). Patients with progressive glaucoma exhibited significantly more MvD than the stable patients in both DH and no-DH groups. There were statistically significant differences between groups subdivided by the presence of DH and MvD as assessed by Kaplan-Meier analysis (log-rank test, P < 0.001). The angle of MvD was significantly greater in eyes with recurrent DH compared with eyes with single DH. Presence of DH, recurrent DH, and presence of MvD were factors associated with progressive RNFL thinning. Conclusions: We found that MvD was frequent in progressive OAG eyes on the choroidal map of OCT-A, which was more frequently found at the prior DH locations in eyes with DH. This means that observing the presence of MvD using OCT-A may provide a biomarker for glaucoma progression, especially in eyes with DH. (C) 2018 by the American Academy of Ophthalmology