Pseudoexfoliation syndrome predisposes to dry eye disease

Abstract

Purpose : Up to 44% of pseudoexfoliation syndrome (PEX) progress to pseudoexfoliative glaucoma (PEG) and glaucoma worsens dry eye disease (DED). Limited evidence show possible implication of PEX in DED development. We hypothesized that PEX predisposes to DED. We performed a prospective, cross-sectional, comparative, case-control study to compare DED parameters in PEX, PEG and normal subjects.

Methods : We included 144 eyes of 72 patients divided in 3 groups; PEX (n=36): PEX with no glaucoma, PEG (n=23) and control (n=85). Male gender cases were 42%, 57% and 22% in PEX, PEG and controls respectably (p<0.002). Age (mean ± standard deviation, SD) was 76±7, 75±6 and 73±8 in PEX, PEG and control groups respectably (p=0.147). All eyes were evaluated for tear osmolarity (TearLab system), cornea staining (NEI-CLEK scale), sensitivity (Cochet-Bonnet), tear break up time (TBUT), Schirmer, ocular surface disease index (OSDI), lid border morphology, glands expressibility, meibum quality and hyperemia. Independent Student’s t-test, Pearson Chi², ANOVA and Bonferroni tests were used for statistical analysis.

Results : Tear osmolarity (mean±SD) was higher in PEX (314.1±22) and PEG (313.4±16) than controls (303.0±17) (p=0.003) but similar between PEX and PEG (p=0.185). Corneal staining (mean±SD) was greater in PEX (1.28±1.3) and PEG (2.22±2.6) than controls (0.26±0.6) (p≤0.001) and greater in PEG than PEX (p≤0.001). Corneal Sensitivity (mean±SD) was less in PEX (5.19±1.0) and PEG (4.91±1.1) than controls (5.75±0.6) (p≤0.001) but similar between PEX and PEG (p=0.398). We found in PEX and PEG a higher proportion than controls with thickened & irregular lid border, thickened & anteriorizated Marx’s line, cloudy or granular meibum & hyperemia (p<0.05). Schirmer (15.3±6.7, 14.7±5.6 and 14.5±4.7), TBUT (6.8±2.7, 7.4±3.7 and 6.2±2.8), OSDI (49.4±25.6, 35.28±21.5, 44.40±27.8) and Meibomian gland expressivity showed no differences between PEX, PEG and controls (p>0.05).

Conclusions : PEX has as greater predisposition for DED than controls in most of the evaluated tests. PEX and PEG have elevated tear osmolarity, greater cornea staining, reduced corneal sensitivity, altered meibum and lid margin morphology, but normal TBUT and Schirmer. Tear osmolarity a DED biomarker indicates ocular surface inflammation; chronic ocular surface inflammation may lead to alteration in many DED parameters. A limitation of our study is the significant difference in gender between groups.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.