Intensive Glycemic Management is Associated with Reduced Retinal Structure Abnormalities on Ocular Coherence Tomography in the DCCT/EDIC Study

OBJECTIVE

To investigate quantitative and qualitative changes in retinal structure using optical coherence tomography (OCT) and their associations with systemic or other risk factors in individuals with type 1 diabetes.

RESEARCH DESIGN AND METHODS

In the Epidemiology of Diabetes Interventions and Complications study, OCT images were obtained during study years 25–28 (2019-2022) in 937 participants; 54% and 46% were from the original intensive (INT) and conventional (CONV) treatment groups, respectively.

RESULTS

Participants were on average 61 years old with diabetes duration of 39 years and HbA1c 7.6%. Participants originally in the CONV group were more likely to have disorganization of retinal inner layers (DRIL) (CONV: 27.3% vs INT: 18.7%; P=0.0003), intraretinal fluid (CONV 24.4% vs INT 19.2%; P=0.0222), and intraretinal cysts (CONV 20.8% vs INT 16.6%; P=0.0471). In multivariable models, sex, age, smoking, mean updated SBP, and history of CSME and of anti-VEGF treatment were independently associated with changes in central subfield thickness, while HbA1c, BMI, history of CSME and of ocular surgery were associated with DRIL. Visual acuity decline was associated with significant thinning of all retinal subfields except for the central and inner nasal subfields.

CONCLUSIONS

Early intensive glycemic management in type 1 diabetes is associated with a decreased risk of DRIL. This important morphological abnormality was associated with a history of macular edema, a history of ocular surgery and worse visual acuity. This study reveals benefits of intensive glycemic management on the retina beyond features detected by fundus photographs and ophthalmoscopy.