Regional Variation in Guttae Distribution in Fuchs Endothelial Corneal Dystrophy

To investigate regional variations in guttae distribution in Fuchs endothelial corneal dystrophy (FECD) and evaluate its relationship with anatomical ultraviolet (UV) protection by the eyelid.

A prospective observational study.

This study involved 19 eyes of 19 patients with FECD between April 2022 and June 2024 at Kyoto Prefectural University of Medicine.

Using slit-scanning wide-field contact specular microscopy, we analyzed guttae distribution in 5 corneal regions (central, superior, temporal, nasal, and inferior). Marginal reflex distance (MRD) was measured to assess the eyelid position. Proportion of guttae was quantified using image analysis.

Regional differences in guttae distribution and correlation with MRD measurements.

The superior region demonstrated a significantly lower proportion of guttae (29.4%) compared with central (69.0%), temporal (57.4%), and nasal areas (57.5%) (all P < 0.05). The difference between superior and inferior areas (45.6%) was not significant (P = 0.08). Margin reflex distance measurements showed no significant correlation with superior guttae distribution (P = 0.40).

Our study reveals a distinct regional variation in FECD progression, with relative sparing of the superior cornea suggesting potential UV-protective mechanisms. Although not directly correlated with eyelid position, these findings indicate that environmental factors may influence disease progression. This insight suggests the potential benefit of UV protection as a preventive strategy, particularly in early-stage FECD patients.

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