Abstract
Purpose:
To examine retrobulbar blood flow in patients with open-angle glaucoma (OAG) with and without diabetes (DM) over a 4-year period.
Methods:
112 patients with OAG (21 with DM, 91 without DM) were assessed for retrobulbar blood flow in the ophthalmic (OA), central retinal (CRA), nasal (NPCA) and temporal (TPCA) posterior ciliary arteries as measured by color Doppler imaging. 78 (13 with DM, 65 without DM) patients were assessed at 4-year follow-up. Mixed-model ANCOVA was used to test for significance of changes from baseline to 4-years. Progression was defined as 2 consecutive visits with a mean deviation (24-2 SITA) decrease by at least 2 compared to baseline and/or AGIS increase by at least 2 compared to baseline. Two-sample t-tests were used to test for differences in baseline data between patients who progressed and those who did not. p<0.05 was considered statistically significant.
Results:
In OAG patients with DM, CRA resistive index (RI) significantly increased from 0.687 (95% CI; 0.656, 0.719) at baseline to 0.756 (0.723, 0.789) at 4 years with a change of 0.069 (0.027, 0.111; p=0.0015). In patients without DM, these were not significant (p=0.10), resulting in a significant difference between groups (p=0.0266). There was no significant difference in OA RI changes between groups (p=0.95). 7 patients with DM progressed with a mean baseline TPCA RI of 0.724 (SE=0.021), which was significantly higher than the TPCA RI of the 14 patients with DM that did not progress (0.652 (0.020); p=0.0245). There was no significant difference in TPCA RI in the patients without DM that progressed and those that did not (p=0.61) which lead to a significant difference between patients with and without DM (p=0.0178). There was no significant difference in baseline NPCA RI (p=0.56) or IOP (p=0.75) effects on progression between the two groups.
Conclusions:
In this cohort of patients with OAG, CRA vascular resistance significantly increased in patients with DM over a 4-year period. Additionally, a higher RI in the TPCA was predictive of progression in patients with DM. These relationships were not seen in the OAG patients without DM despite similar IOP. Blood flow to the retina and optic nerve head may be altered in OAG patients with DM.
Keywords: 436 blood supply •
572 ischemia •
498 diabetes