Abstract
Purpose :
To examine retrobulbar blood flow velocities and functional progression in open-angle glaucoma (OAG) patients with and without diabetes mellitus (DM) over a five-year period
Methods :
111 patients with OAG (21 with DM, 90 without DM) were assessed for peak systolic velocity (PSV) and end diastolic velocity (EDV) in the ophthalmic artery (OA) and nasal posterior ciliary artery (NPCA) every six months for five years. Functional progression, evaluated by Humphrey 24-2 visual fields, was defined as two consecutive visits with mean deviation decrease ≥2 compared to baseline and/or Advanced Glaucoma Intervention Study score increase ≥2 compared to baseline. Mixed-model ANCOVA was used to test for statistically significant changes from baseline to five-year follow-up. Time to functional progression was analyzed using Cox proportional hazard survival analysis. Interactions were tested to determine if the effects of the factors on progression time differed by diabetes status.
Results :
In OAG patients without DM, OA EDV decreased from baseline 6.0 to 4.4 at five years, mean change of -2.2 (95% CI -3.2, -1.4; p<0.001), NPCA EDV decreased from 2.4 to 1.9, mean change of -0.6 (-0.9, -0.4; p<0.001), while NPCA PSV did not significantly change from 7.5 to 7.4, mean change of 0.0 (-0.6, 0.5; p=0.871). Similarly in patients with DM, OA EDV decreased from 5.4 to 3.2, mean change -3.6 (-6.0, -1.7; p<0.001), NPCA EDV decreased from 2.4 to 1.6, mean change -1.1 (-1.8, -0.6; p<0.001), while NPCA PSV did not significantly change from 7.7 to 7.4, mean change of -0.4 (-1.5, 0.8; p=0.553). In diabetic patients, a smaller decrease in NPCA PSV was associated with shorter time to functional progression, while in patients without diabetes, a larger decrease in OA EDV and NPCA EDV were associated with shorter time to functional progression (p<0.05).
Conclusions :
In this study, we found that changes in retrobulbar blood flow velocity have different effects on time to functional glaucoma progression in diabetics and non-diabetics. More research is required to understand how vascular contributions to the glaucoma disease process may be influenced by diabetes.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.