Lower baseline retinal capillary blood flow predicts functional glaucoma progression in obese patients with open-angle glaucoma.

Abstract

Purpose: To examine the retinal capillary blood flow parameters and functional progression in patients with different Body Mass Index (BMI) with open-angle glaucoma (OAG) over a 5-year period.

Methods: 112 patients with OAG (38 normal weight, BMI <25, NW; 40 overweight, BMI 25-30, OW; 34 obese, BMI>30, OB) were assessed for retinal capillary blood flow as measured by Heidelberg retinal flowmetry at baseline and every 6 months for a 5-year period. 30 patients (9 NW, 13 OW, 8 OB) were assessed at 5-year follow-up. Functional disease progression was monitored with 24-2 Swedish Interactive Thresholding Algorithm visual field exam using the Humphrey visual field machine and was defined as two consecutive visits with mean deviation decrease ≥2 and/or Advanced Glaucoma Intervention Study increase ≥2 compared to baseline. Mixed-model ANCOVA was used to test for significant change from baseline to 5-year follow-up. Time to functional progression was analyzed using Cox proportional hazards models. Interactions were tested to determine if the effects of the factors on progression time differed by BMI category.

Results: Inferior mean flow at baseline was 413.67 (95% CI; 368.98, 461.55) for NW, 415.82 (375.76, 460.15) for OW and 403.28 (360.46, 451.18) for OB. Lower baseline inferior mean flow was associated with shorter time to structural progression in OB patients (p=0.01440) but neither in NW (p=0.2475) nor OW patients (p=0.7323), leading to a significant difference between groups (p=0.0317).

Conclusions: Lower baseline inferior mean flow was predictive of glaucomatous functional progression in OB but neither in NW nor in OW. These findings suggest that capillary blood flow may play a different role in the functional progression of the disease according to BMI.