Sectoral differences in the association of optic nerve head blood flow and glaucomatous visual field defect severity and progression

PURPOSE. To investigate sectoral differences in the relationship between optic nerve head tissue blood flow, anatomically corresponding visual field defect severity, and future progression. METHODS. This retrospective longitudinal medical chart review comprised 508 eyes of 319 open-angle glaucoma patients (mean deviation: -9.2 ± 7.0 dB), followed for an average of 4.7 ± 1.1 years; an average 11.7 ± 3.7 visual field tests were performed. Average total deviation (TD) was calculated in the superior, central, and inferior sectors of the Humphrey 24-2 program. The optic nerve head was divided to obtain inferior, temporal, and superior tissue-area mean blur rate (MT), derived from laser speckle flowgraphy. At baseline, the correlation between MT and TD was compared in anatomically corresponding sectors. We performed a multivariate analysis to determine the contribution of baseline MT to corresponding TD slope and to determine background factors influencing superior to temporal MT. We used a linear-mixed effect model for the statistical analysis. RESULTS. At baseline, the highest β coefficients were found between MT-superior and TDinferior, MT-temporal and TD-central, and between MT-inferior and TD-superior, in that order (β = 0.38, β = 0.27, β = 0.26, respectively). MT-superior and MT-temporal independently contributed to corresponding TD slope (P < 0.05). Male sex, high body mass index, and the prevalence of sleep apnea syndrome were contributing factors to lower superior to temporal MT (P < 0.05). CONCLUSIONS. Review of medical history, measurements of systemic variables, and laser speckle flowgraphy parameters might help clinicians to predict visual field defect severity and progression.