Corneal epithelial thickness in pseudoexfoliation syndrome: an anterior segment optical coherence tomography study

This study aimed to characterize corneal epithelial thickness profiles in pseudoexfoliation syndrome (PXS) patients using AS-OCT and to investigate its correlation with intraocular pressure (IOP).

In this prospective, cross-sectional study, 27 PXS patients and 26 controls underwent a comprehensive ophthalmologic examination. Corneal epithelial and total thickness were measured in central, 0-2 mm, 2-5 mm, and 5-7 mm zones using Carl Zeiss Cirrus 5000 HD-OCT. Statistical comparisons and correlations were performed.

Mean IOP was significantly higher in PXS patients (17.8 ± 6.9 mmHg) versus controls (14.0 ± 3.8 mmHg; p = 0.01). Central corneal thickness (CCT) was also significantly greater in PXS eyes (536.33 ± 33.62 µm) compared to controls (515.19 ± 30.16 µm; p = 0.02), with similar significant differences across all pachymetry zones. Stromal plus endothelial thickness was significantly higher in PXS centrally (p = 0.04), in the 0-2 mm (p = 0.03) and 5-7 mm (p = 0.02) zones, but this difference was non-significant in the 2-5 mm zone (p = 0.09). Crucially, epithelial thickness measurements across all zones showed no significant differences between groups (all p > 0.05). Similarly, epithelial thickness ratios to total corneal and stromal plus endothelial thickness remained unchanged (all p ≥ 0.05). While IOP was significantly positively correlated with total corneal thickness in both groups, no significant correlation was found between IOP and epithelial thickness (all p > 0.05).

Despite increased overall corneal thickness and IOP, corneal epithelial thickness profiles in PXS remained stable. Our results suggest that the PXS may primarily affect the deeper layers (stroma and endothelium) and that the epithelial layer maintains structural integrity. This is clinically relevant, as a stable epithelium may help differentiate PXS-related keratopathy from other anterior segment disorders and may guide clinicians to focus on the underlying stromal and endothelial health for diagnosis and surgical planning.