Asymmetric Corneal Endothelial Alterations In Clinically Unilateral Pseudoexfoliation Syndrome

To quantitatively evaluate and compare corneal endothelial cell parameters among eyes with unilateral pseudoexfoliation (PXF) eyes, their clinically contralateral unaffected eyes, and normal control eyes. The study specifically aimed to identify subclinical structural alterations in fellow eyes and to clarify whether unilateral PXF demonstrates evidence of bilateral ocular involvement.

This retrospective, cross-sectional observational study was conducted at Kangwon National University Hospital. Medical records of patients who visited the hospital between January 2015 and December 2025 were reviewed.

Thirty-nine patients diagnosed with unilateral pseudoexfoliation (PXF) were included. Three groups were analyzed: PXF eyes (Group 1), contralateral unaffected eyes (Group 2), and age- and sex-matched normal control eyes (Group 3). Corneal endothelial parameters—including endothelial cell density (ECD), coefficient of variation (CV), hexagonality, and central corneal thickness (CCT)—were measured using specular microscopy. Inter-group comparisons were performed using one-way analysis of variance (ANOVA), followed by post hoc multiple comparison tests. A p-value <0.05 was considered statistically significant.

Each group comprised 39 eyes. ECD differed significantly among groups (2466.7±421.2 vs 2619.0±335.8 vs 2740.5±316.5 cells/mm²; overall p=0.005). Post hoc analysis demonstrated significantly lower ECD in PXF eyes compared with controls (p=0.003), whereas the difference between contralateral fellow eyes and controls was not significant. CV differed among groups (overall p=0.021) and was higher in contralateral fellow eyes than controls (32.95±12.61 vs 25.87±10.90). 

Unilateral PXF was associated with significant corneal endothelial cell loss predominantly in affected eyes, while contralateral unaffected eyes showed only limited endothelial differences compared with controls. However, these subtle changes may still indicate subclinical endothelial stress and early or asymmetric bilateral involvement. Therefore, monitoring of both eyes should be considered.