Association Between the Deep-layer Microvasculature Dropout and the Visual Field Damage in Glaucoma

PURPOSE: To compare the visual field (VF) sensitivity according to the presence of parapapillary deep-layer microvasculature dropout (MvD_P) and focal lamina cribrosa (LC) defect. MATERIALS AND METHODS: Among 158 open-angle glaucoma patients, 4 groups were formed according to the presence of MvD_P and focal LC defect determined by optical coherence tomography (OCT) angiography and by enhanced depth imaging spectral-domain OCT, respectively: (1) eyes without either focal LC defect or MvD_P (group 1); (2) eyes with focal LC defect but no MvD_P (group 2); (3) eyes without focal LC defect but with MvD_P (group 3); (4) eyes with both focal LC defect and MvD_P (group 4). VF sensitivity and retinal nerve fiber layer (RNFL) thickness were compared among the 4 groups for global area and 6 sectors. RESULTS: Both RNFL thickness and VF sensitivity differed among the 4 groups in all areas other than the nasal and superonasal sectors for RNFL thickness. On post hoc analysis, eyes with MvD_P (groups 3 and 4) had significantly worse VF sensitivity than group 2 [P<0.05, 1-way analysis of variance (ANOVA)] in all areas except the superotemporal and temporal sectors, whereas the RNFL thicknesses did not differ (P>0.05, 1-way ANOVA) in any areas except the superotemporal sector. CONCLUSIONS: Eyes with MvD_P had worse VF sensitivity than those without MvD_P, and VF difference was more distinguished than differences of axonal loss and focal LC change. Further studies on the temporal relationship between the MvD_P and glaucomatous VF progression are warranted.