Metabolic Status Modulates Choroidal Thickness – A Possible Early Indicator for Diabetic Eye Complications?

Abstract

Objective To investigate the impact of metabolic status on choroidal thickness in healthy subjects, patients with obesity, and type 2 diabetes. Design and Methods Fasting blood glucose, insulin, IGF-1, and choroidal thickness measured by optical coherence tomography were assessed in healthy normal-weight (n=17), obese participants (n=20), and in obese participants with T2D (n=16). Results Choroidal thickness was increased in obese participants and obese participants with T2D as compared to healthy normal-weight participants (P<0.0001). There was a negative correlation between IGF1 and choroidal thickness (r=-0.268, P=0.050) for all cohorts. Furthermore, BMI (R2=0.209; P=0.002; beta=0.388) and HOMA-IR (R2=0.074; P=0.015; beta=0.305) are independent variables of ChT, explaining 20.9% and 7.4% of its variance (both p<0.016), whereas age, sex, and IGF-1 were not significant confounders of ChT (p>0.975). Conclusion Choroidal thickness is associated with metabolic characteristics, i.e. BMI and HOMA-IR. Due to the key role of choroidal function in retinal physiology, future studies are needed to evaluate whether metabolic traits, choroidal thickness, and potential metabolic eye complications are mechanistically linked.