Choroidal thickness changes in patients with diabetes

INTRODUCTION: Swept-source optical coherence tomography is a useful non-invasive device that is used to understand better the role of choroid in the pathogenesis of diabetic retinopathy.

AIM: To measure choroidal thickness in diabetic eyes and to correlate it with established systemic risk factors, the severity and the therapy of diabetic retinopathy.

METHOD: Prospective cross-sectional study using swept-source optical coherence tomography has been performed. Choroidal and macular thickness maps of 117 eyes of 60 diabetic patients were compared to data from 45 eyes of 24 healthy controls. In all diabetic patients, the systemic risk factors (duration and type of diabetes, blood hemoglobin A1C level, hypertension), the type (no, non-proliferative or proliferative) and the therapy of diabetic retinopathy were recorded, and their relation to choroidal thickness was evaluated using multiple regression models.

RESULTS: A significantly thinner choroid was measured in diabetic patients compared to controls (p<0.05). Analysing the whole cohort, aging (p<0.001) and the presence of hypertension (p<0.05) showed significant correlation with choroidal thinning. In diabetic patients, the duration of diabetes significantly correlated with choroidal thinning (p<0.05). In multivariable analysis, the duration of diabetes remained a significant predictor of choroidal thickness (β -0.18; p = 0.02). A significantly thinner choroid was measured in patients with proliferative retinopathy and in patients after panretinal photocoagulation treatment compared to nonproliferative retinopathy (p<0.05).

CONCLUSION: Diabetes mellitus itself and diabetic retinopathy progression affects choroidal thickness significantly. Choroidal thickness is affected significantly by systemic risk factors (age, the presence of hypertension, disease duration). Choroidal thinning proved to be correlated with panretinal photocoagulation treatment of diabetic retinopathy. Orv Hetil. 2020; 161(35): 1475-1482.