Abstract
Purpose :
Diabetes mellitus is known to affect microvasculature such as that of the retina, but little is known of its effects on conjunctival vasculature. This study used functional slit lamp biomicroscopy (FSLB) to investigate diabetic changes in conjunctival microvessels and examined these changes as possible predictors of diabetes-related complications.
Methods :
This cross-sectional study included 21 patients with diabetes-related complications (D+C), 13 with diabetes but no complications (D-C), and 98 healthy controls (C). Diabetic complications included retinopathy, nephropathy, neuropathy, cardiovascular-, peripheral vascular-, and cerebral vascular disease. Bulbar conjunctival metrics (vessel diameter, length, axial velocity (Va), cross-sectional velocity (Vs), flow (Q), and complexity of morphology) were measured using the FSLB imaging system (digital camera mounted on traditional slit lamp).
Results :
Significant differences in Va and Vs were found between all three groups. Va was 0.45 ± 0.17 mm/s in the D+C group, 0.62 ± 0.17 mm/s in the D-C group, and 0.51 ± 0.17 mm/s in controls (p = 0.025). Vs was 0.32 ± 0.13, 0.43 ± 0.13, and 0.35 ± 01.12 mm/s in the D+C, D-C, and control groups, respectively (p = 0.031). Patients identifying as black or African American had significantly increased blood flow metrics (Va, Vs, and Q) when compared to patients of other racial backgrounds (p < 0.05), but the differences in velocities persisted after accounting for the effect of race. Post-hoc pairwise comparisons found that the D-C group had higher velocities than either the D+C or C group. Among patients with diabetes, Va (r = -0.42, p = 0.016) and Vs (r = -0.406, p = 0.021) correlated with number of diabetes-related complications. All measures of blood flow (Va, Vs, and Q) statistically significantly (p<0.005) discriminated between diabetic patients with and without complications (AUROC(Va) = 0.81, AUROC(Vs) = 0.79, AUROC(Q) = 0.81).
Conclusions :
Bulbar conjunctival blood flow metrics measured by FSLB differ between diabetics with complications, diabetics without complications, and healthy controls. These metrics may help predict risk for complications in patients with diabetes.
This is a 2020 ARVO Annual Meeting abstract.