Preperimetric Glaucoma Prospective Study (PPGPS): Predicting Visual Field Progression With Basal Optic Nerve Head Blood Flow in Normotensive PPG Eyes

PURPOSE: To investigate the site specificity of visual field changes in eyes with normotensive preperimetric glaucoma (PPG), and to determine factors influencing visual field progression. METHODS: This prospective study comprised 84 eyes of 84 normotensive PPG patients followed for at least 16 months. Optic nerve head (ONH) blood flow was assessed with tissue-area mean blur rate (MBR(T)), derived from laser speckle flowgraphy. Total deviation (TD) was measured in each sector of the Garway-Heath map to evaluate the site specificity of visual field loss. Subjects with a TD slope in the first quartile were classified as progressive, and other subjects as nonprogressive. Linear and multiple regression analyses were performed to determine factors affecting visual field progression. RESULTS: TD in the superior sector significantly decreased in the subjects overall during the follow-up periods (−0.48 ± 1.92 dB/y, P = 0.025). Linear regression analysis showed that basal MBR(T)-inferior was correlated significantly with TD-superior slope (r = 0.332, P = 0.002). Furthermore, basal MBR(T) was significantly lower in this sector in the progressive than the nonprogressive group (P = 0.010). Multiple linear regression analysis revealed that basal MBR(T)-inferior was the only predictive factor for TD-superior slope (β = 0.329, P = 0.005). CONCLUSIONS: These findings suggest that superior-sector visual field progression is most common in normotensive PPG eyes, and that reduced basal ONH blood flow is associated with visual field progression. TRANSLATIONAL RELEVANCE: These findings provide new insight into the involvement of ONH blood flow impairment in glaucoma pathogenesis, and demonstrate the importance of assessing ONH blood flow to determine visual field progression in normotensive PPG.