Smoking, diabetes mellitus and obesity as risk factors for the degree of fuchs endothelial corneal dystrophy (FECD)

Abstract

Aims/Purpose: To detect environmental factors, which may be possible risk factors in the disease course of Fuchs endothelial corneal dystrophy (FECD).Methods: Evaluation of patients with FECD registered in the FECD genetics database of the Center for Ophthalmology, University Hospital Cologne, from 2018 to 2019. For the evaluation, disease onset, central corneal thickness (CCT), best corrected visual acuity (BSCVA, logMAR), and age‐related Krachmer grading were correlated with the presence of diabetes mellitus (DM), body mass index (BMI), and smoking behaviour. Depending on the variables studied, differences between groups were examined by Mann–Whitney U test and chi‐square test. The significance level was 5%. Krachmer Grading was age‐corrected by using ordinal regression in the mediation analysis. For the mediation analysis the Kenny and Barron 4 Step Analysis was used.Results: 403 patients with FECD were included in the analysis. The mean age at diagnosis was 63.1 (±13.2) years. The female‐to‐male ratio was 1.46:1. Patients with a BMI of 30.0–34.9 kg/m2 developed FECD significantly earlier than patients with a BMI < 30 kg/m2 (p = 0.001). Patients with DM showed significantly more often an age corrected Krachmer grade of 5 compared to patients without DM (p = 0.015). Using the mediation analysis, the presence of DM correlated with age‐corrected Krachmer Grade 5 (p = 0.015), and the presence of DM correlated with BMI of 30.0–34.9 kg/m2 (p = 0.012). BMI of 30.0–34.9 kg/m2 exerts a significant effect on age‐corrected Krachmer grading grade 5 with p = 0.005. The effect of DM on age‐corrected Krachmer Grading 5 is significantly mediated by BMI‐ Group 4 using Kenny and Barron 4 Step Analysis, p = 0.013.Conclusions: Our study shows for the first time that obese individuals develop FECD significantly earlier than non‐obese individuals. Oestrogen secretion in premenopausal women occurs mainly in the ovaries, whereas postmenopausal oestrogens are produced in adipose tissue. Together with gender as a risk factor, this may indicate that oestrogens have a relevant influence on disease progression. Initial laboratory work has shown that oestrogen metabolites have genotoxic and apoptotic effects on corneal endothelial cells.