The Role of Sensor-Derived Daily Glycemic Variability in Treatment-Requiring Diabetic Ocular Disease: A Retrospective Case-Control Study.

Abstract

Objective: Daily glycemic variability (GV) has been proposed as a contributor to diabetic ocular complications beyond chronic glycemic management. This study evaluated whether sensor-derived GV (coefficient of variation, %CV) is associated with treatment-requiring diabetic ocular disease.

Methods: Retrospective case-control study of adults with diabetes followed by Endocrinology departments at 2 tertiary hospitals in Kingston, Ontario. Inclusion criteria were as follows: diabetes duration ≥5 years, age ≥18 years, continuous glucose monitoring (CGM) wear ≥70% in a continuous 90-day period (Jan 2023-May 2024), and a documented eye examination (Jan 2023-Dec 2024). Cases were identified as having received diabetic ocular treatment (intravitreal injection [IVI], retinal laser, and/or pars plana vitrectomy) using OHIP codes (2015-2024) and confirmed by blinded ophthalmology chart review; controls had not received such treatment. Device-reported 14- and 90-day CGM metrics were extracted. In cases treated between 2022 and 2024, IVI burden was compared by 90-day %CV (≤36 vs >36) and correlated with CGM metrics.

Results: Among 485 patients, 72 (14.8%) were cases. Cases were older and had a longer diabetes duration than controls (both p<0.0001). There were no differences between cases and controls in 14- or 90-day GV (%CV), mean glucose, or time in range. In 57 recently treated cases (2022-2024), IVI burden was higher in the low %CV group than in the high %CV group (9.9 vs 6.3; p=0.046). %CV had a weak negative, nonsignificant correlation with IVI count, whereas time in range correlated positively with IVI count (r=0.351; p=0.012).

Conclusions: Short-term CGM-derived GV was not associated with treatment-requiring diabetic ocular disease. Within recently treated patients, GV-treatment relationships likely reflect confounding by care intensity and disease stage.