Abstract
Purpose :
To evaluate choroidal thickness (CT) in diabetic eyes, and to correlate it with the effect of systemic risk factors and the severity of diabetic retinopathy (DR).
Methods :
Prospective cross-sectional study using swept-source optical coherence tomography. Choroidal thickness maps - according to the nine Early Treatment Diabetic Retinopathy Study subfields - of 96 treatment naiv eyes of 48 diabetic patients were compared to 46 eyes of 23 healthy controls. Choroidal thickness changes and their relation to diabetes, age, gender and hypertension (HT) was analysed. In diabetic patients, the effect of disease duration and blood hemoglobin A1C (HbA1C) level were also evaluated. Furthermore the association of CT and the severity of DR (no DR, nonproliferative DR, nonproliferative DR with diabetic macular edema and proliferative DR) was assessed.
Results :
A significantly thinner choroid was measured in patients with diabetes compared to controls (p<0.005). In diabetic patients age (25 μm thinning per decade; p<0.001), male gender (p<0.001), the duration of the disease (15 μm decrease in CT / 10 duration years; p=0.02) and HT (p=0.003) were significant predictors of choroidal thinning in univariable regression models. The level of HbA1c proved not to be correlated with CT. After analysing the effect of systemic risk factors in multivariable model, the duration of diabetes remained a significant predictor of CT decrease (p = 0.03). There was a significant correlation between choroidal thinning and the different stages of DR (p = 0.002). In multivariable analysis, thinner CT was found to be a significant predictor of the presence of DR (p = 0.02), after adjusting for the effect of systemic risk factors.
Conclusions :
Diabetes mellitus itself and DR progression affects CT significantly even after adjusting for the effect of confounding systemic risk factors. Duration of the disease seems to be a prominent predictor of choroidal thinning. Thinner CT proved to be correlated with the progression of DR.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.