Abstract
Purpose: :
There are no known consistent non-genetic risk factors for Fuchs’ Endothelial Corneal Dystrophy (FECD). The Reykjavik Eye Study showed that smoking one pack per day for 20 years increased the odds of guttae development specular microscopically by 2-fold. These observations remain unsubstantiated, thus we investigated if FECD severity is associated with smoking in a large multi-center observational study.
Methods: :
Eyes from Caucasian index cases, family members, and unrelated controls with normal corneas from the FECD Genetics Multi-Center Study (n=4092 eyes from 2046 subjects), matched for age, were examined. To estimate the association between FECD severity grade (7-point severity scale based on guttae confluence and corneal edema) and self-reported smoking, a multivariable model was used that adjusted for eye, central corneal thickness (CCT) measured by ultrasonic pachymetry, and sex.
Results: :
In this study 24.4% of cases and 27.9% of controls had ever smoked. The sample was 65.5% female and 34.5% male. Cases (n=2866 eyes) and controls (n=1226 eyes) were similar in age with mean ages of 68.3 (±12.1) and 69.9 (±10.9) years, respectively. In univariate models smoking showed borderline significance (ß = -0.294, p =0.04). The most significant risk factors were CCT(ß =0.019, p=2 x 10-16) and sex (ß =0.44, p=0.0014). In a joint model considering smoking, CCT and sex together, the most significant predictors remained CCT and sex. Smoking was no longer significant in this model.
Conclusions: :
Given the pathology of FECD, it is not surprising that CCT has a positive correlation with FECD grade. Female sex also had a positive correlation with FECD severity. This could be explained by the increased lifespan of females, or more likely the effect of hormonal changes on FECD progression. Finally, we were unable to confirm the relationship between smoking and severity of FECD. The Reykjavik Eye Study was longitudinal and focused on early events in FECD initiation using specular microscopy to assess changes in guttae, together with detailed smoking history. The contrast in our results suggests that smoking may have a relationship with early changes in guttae confluence, but may not be as influential in later stages of FECD development.
Keywords: clinical (human) or epidemiologic studies: outcomes/complications • clinical (human) or epidemiologic studies: risk factor assessment • cornea: endothelium