Risk factors for progression of diabetic retinopathy in Alberta First Nations communities.

OBJECTIVE

The Screening for Limb, I-Eye, Cardiovascular, and Kidney Complications (SLICK) Program was implemented in 1999 to improve diabetic care for Alberta First Nations individuals living on reserve. The purpose of this review is to determine the rate and predictors of progression of diabetic retinopathy (DR) over a 10-year period.

DESIGN

Cohort study.

PARTICIPANTS

Nine hundred and eighty First Nations patients with diabetes that underwent at least 2 teleophthalmology examinations during the study period.

METHODS

Patients underwent serial laboratory testing, and stereoscopic, mydriatic, retinal photography. Modified Early Treatment Diabetic Retinopathy Study grading of retinal images was performed via teleophthalmology. Progression was defined as an increase of 2 or more steps on the Diabetes Control and Complications Trial classification.

RESULTS

At baseline, most patients had no diabetic retinopathy (n = 777, 79.3%) whereas 203 people (20.7%) had either nonproliferative DR (n = 179, 18.3%) or proliferative DR (n = 24, 2.5%). Two-step progression occurred in 163 patients (16.6%), with only a minority of these individuals progressing to proliferative DR (n = 23). The median time to progression was 7.6 years. Multivariate Cox regression demonstrated that elevated hemoglobin A1C (hazard ratio [HR] = 1.42; p < 0.0001) and systolic blood pressure (HR = 1.24 per 10 mm Hg; p = 0.009) were independent predictors of progression of DR.

CONCLUSIONS

This population-based study has shown that the rate and predictors of progression of DR among First Nations individuals parallels non-First Nations populations, with HbA1C and systolic blood pressure being the strongest predictors. These findings suggest that targeted, individualized care to reduce blood pressure and control blood sugars could reduce progression of diabetic retinopathy, and possibly blindness in First Nations individuals living on reserve.