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 TD-inferior, 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.