Long-term effect on HbA1c in poorly controlled diabetic patients following nonmydriatic retinal image review at the time of endocrinology visit

Abstract

Background: Patient education demonstrates variable benefits on diabetes control. Introduction: To examine the effect of discussing nonmydriatic retinal imaging findings during a single endocrinology visit on HbA1c levels after 6, 12, and 60 months. Materials and Methods: Patients with HbA1c >8.0% and diabetic retinopathy were previously recruited for a prospective study looking at the change in HbA1c at 3 months between those assigned to a session of nonmydriatic imaging with discussion of retinal findings and those assigned to routine endocrinology evaluation alone. The patients were subsequently evaluated at 6, 12, and 60 months after the initial intervention. Results: Fifty-three of the 57 originally recruited intervention subjects (93%) and 48 of 54 subjects in the original control group (89%) were evaluated at 6 and 12 months and 44 patients in each group (75% and 81%, respectively) at 60 months. At 6 months, the intervention group maintained larger decreases in median HbA1c compared to control (-1.1 vs.-0.3, respectively, p = 0.002) with a trend persisting at 12 months (-0.6 vs.-0.2, respectively, p = 0.07). After 60 months, there was no significant difference in the median change in HbA1c between treatment and control groups (0.3 vs. 0.1, respectively, p = 0.54). Discussion: The short-term improvement in HbA1c resulting from discussion of retinal findings persists throughout the first year in this diabetic cohort, but its magnitude declines with time and becomes statistically insignificant at some point between 6 and 12 months. Conclusions: In patients with poorly controlled diabetes, retinal imaging review may help improve glycemic control but may require repetition periodically for benefit beyond 6 months.