Association of blood and ocular perfusion pressure with structural glaucomatous progression by flicker chronoscopy

Background: Vascular risk factors have been associated with glaucomatous visual field progression. Aim: We determined the relationship between vascular risk factors and structural glaucomatous progression using serial flicker chronoscopy images. Methods: Two glaucoma fellowship-trained ophthalmologists, masked to temporal sequence, independently graded serial flicker chronoscopy images from one eye of a cohort of glaucoma patients for features of structural progression in this retrospective cohort study. After adjudication, simple and multiple logistic models were constructed to determine variables associated with increased odds of progression, including systolic blood pressure (BP), diastolic BP and mean ocular perfusion pressure. Results: Seventy-two eyes of 72 patients were analysed. Patients with any form of structural progression (n=40) were older (67.0 vs 58.8 years; p=0.005) and had lower diastolic BP (71.8 vs 76.5 mm Hg; p=0.02) than patients without progression (n=32). In the univariable model, diastolic BP was associated with progressive retinal nerve fibre layer (RNFL) loss (OR=0.2 per 10 mm Hg, 95% CI 0.1 to 0.6, p<0.006) and neuroretinal rim loss (OR=0.4 per 10 mm Hg, 95% CI 0.2 to 0.8, p<0.01). Diastolic BP was also significant in the multivariable model for RNFL loss ( p=0.009) and neuroretinal rim loss (p=0.003). Conclusions: This study is the first to use structural progression and flicker chronoscopy to identify vascular glaucoma risk factors. Older age and lower diastolic BP were associated with progression. By multivariable analysis diastolic BP was associated with RNFL and neuroretinal rim loss. These findings suggest that diastolic BP is associated with structural glaucomatous progression which may have implications for management.