Evaluation of tear film function and ocular surface disease index in patients with unilateral pseudoexfoliation syndrome.

Abstract

Background: To evaluate tear film function and ocular surface symptoms in unilateral pseudoexfoliation syndrome (PEX) and explore associations between pseudoexfoliative material, tear instability, and ocular surface disease index (OSDI) scores.

Methods: Sixty-seven unilateral PEX patients and 72 matched healthy controls were enrolled. Tear break-up time (TBUT), non-invasive TBUT (NIBUT), basal Schirmer test (BST), and OSDI questionnaire were assessed in PEX-affected eyes (Group 1), fellow eyes (Group 2), and controls (Group 3). Statistical comparisons were performed using paired and independent t-tests or their non-parametric equivalents, and Chi-square analysis for OSDI categories.

Results: Mean TBUT was 7.93 ± 2.9 s (G1), 8.93 ± 2.8 s (G2), and 10.04 ± 2.05 s (G3), with G1 and G2 significantly lower than G3 (p < 0.001, p = 0.032). Mean NIBUT was 7.84 ± 2.8 s (G1), 8.15 ± 2.6 s (G2), and 9.42 ± 2.8 s (G3), with G1 and G2 lower than G3 (p < 0.002, p = 0.02). BST was 8.01 ± 3.05 mm (G1), 8.28 ± 3.38 mm (G2), and 9.97 ± 3.5 mm (G3), significantly reduced in G1 and G2 compared with G3 (p = 0.02, p = 0.041). No significant differences were found between G1 and G2 for these tests (p > 0.05). Severe OSDI symptoms occurred in 22.4% of PEX eyes vs. 7.5% of controls, with a significant overall difference in severity distribution (p = 0.049).

Conclusions: Tear film stability and quantity are reduced in unilateral PEX, affecting even clinically unaffected eyes. The higher prevalence of severe ocular surface symptoms underscores the need for routine ocular surface assessment and early intervention in this population.