Macula vessel density and its relationship with the central visual field mean sensitivity across different stages of exfoliation glaucoma

Clinical relevanceAlterations in ocular microvasculature may contribute to pathogenesis of exfoliation glaucoma (XFG) and may improve monitoring this aggressive type of open angle glaucoma.BackgroundThis work aims to compare the macula vessel density and the relationship between macula vessel density and central visual field mean sensitivity between eyes with XFG and eyes with primary open-angle glaucoma (POAG) of different stages.MethodsIn this cross-sectional observational study, the macula vessel density values were compared among 52 POAG cases (26 early stage, 26 moderate to advanced stage) and 53 XFG cases (27 early stage, 26 moderate to advanced stage). The vessel density values were evaluated with optical coherence tomography angiography. Vasculature-function and structure-function relationships were analysed by comparing macula vessel density, inner macula thickness and visual field mean sensitivity in early and moderate to advanced stages of XFG and POAG eyes separately.ResultsThe early stage XFG eyes had a significantly lower global macula vessel density compared with early stage POAG eyes (42.81 +/- 3.85% and 46.56 +/- 3.90%, respectively; p = 0.02). However, the tendency of XFG eyes for a lower vessel density compared with the POAG eyes did not exhibit any significance in moderate to advanced stages of glaucoma (37.39 +/- 5.65% and 38.35 +/- 4.67%, respectively; p = 0.9). The macula vessel density (%)-visual field mean sensitivity (1/Lambert) correlation was statistically significant in early stage XFG eyes (r = 0.464 p = 0.01), while no such correlation was notable for the early stage POAG eyes (r = -0.029 p = 0.89).ConclusionThe macula vessel density appears to be more severely affected in early stage XFG than POAG of similar severity, suggesting a relatively greater value of vascular insufficiency in XFG. The significant vasculature-function association in early stage XFG, which was absent in early stage POAG, may infer the importance of macula vessel density in monitoring functional loss in early stages of XFG.