Abstract
Purpose:
Identification of progression and modification of risk factors are important for management of glaucoma. We used serial flicker chronoscopy images to determine the relationship between vascular risk factors and structural glaucomatous progression.
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 intraocular pressure (IOP), systolic and diastolic blood pressure (BP) and ocular perfusion pressure (OPP).
Results:
Seventy-two eyes of 72 patients were included for analysis. Patients with any form of structural progression (n=40) were older (67.0 vs. 58.8 years; p = 0.005), had thinner corneas (528.0 vs. 554.1 microns; p = 0.08), had been followed for longer (38.5 vs. 25.1 months; p <0.001) and had lower mean diastolic BP (71.8 vs. 76.5 mm Hg; p = 0.02) than patients with no progression (n=32). Simple logistic models were constructed and central corneal thickness (CCT) (OR = 0.8 per 10 µm, 95% confidence interval (CI) 0.8, 1.0, P < 0.03), and mean diastolic BP (OR = 0.2 per 10 mm Hg, 95% CI 0.1, 0.6, P < 0.006) were associated with progressive retinal nerve fiber layer (RNFL) loss, with both CCT and mean diastolic BP significant in the multivariable model (p=0.01 and 0.009, respectively). For progressive neuroretinal rim loss, simple logistic models revealed associations with duration of follow-up (OR = 1.0 per 6 months, 95% CI 1.0, 1.1, P < 0.02) and mean diastolic BP (OR = 0.4 per 10 mm Hg, 95% CI 0.2, 0.8, P < 0.01) with both terms being significant in the multivariable model (p=0.006 and 0.003, respectively).
Conclusions:
This study is the first to use structural progression and flicker chronoscopy to identify vascular glaucoma risk factors. Older age, thinner corneas, and lower mean diastolic BP were associated with progression. By multivariable analysis, CCT was associated with RNFL loss, while diastolic BP was associated with both RNFL and neuroretinal rim loss. These findings suggest that diastolic BP may be an independent risk factor for glaucomatous progression which may have implications for future management and screening.
Keywords: 550 imaging/image analysis: clinical •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
568 intraocular pressure