Relationship between OSDI score and biomicroscopic ocular surface damages in glaucomatous patients treated with preserved antiglaucomatous eye drops

Abstract

Our goal was to identify factors that may influence the OSDI score, in particular, ocular surface damage in patients on preserved glaucoma eye drops. This was a cross-sectional study of 155 glaucoma patients treated with preserved glaucoma eye drops. They all completed the "Ocular Surface Disease Index" (OSDI) questionnaire and underwent complete ophthalmological examination with precise evaluation of the status of the ocular surface. The assessment included Shirmer I testing, tear break up time (TBUT), eyelid, conjunctival and corneal examination with fluorescein and lissamine green staining. We analyzed factors that may influence the OSDI score and its relationship with the biomicroscopic signs. Benzalkonium chloride (BAK) was used in 80% of cases. The OSDI score was≥13 in 61.3% of cases and classified as severe in 22.6% of cases. The biomicroscopic signs of ocular surface disease were at least minimal in 87.1% of cases. The severity of the OSDI score was statistically associated with patient age (P<0.001), treatment duration (P<0.001), multiple medications (P=0.011), and use of BAK (P=0.004). Blepharitis (P=0.013), Meibomian gland dysfunction (P=0.039), corneal neovascularization (P=0.025) and superficial punctate keratitis (SPK) (P=0.044) were retained as predictors of a pathological OSDI score. A disparity between the severity of symptoms and biomicroscopic signs was noted. Symptoms and clinical signs are complementary for assessment of the various aspects of ocular surface disease. OSDI score is correlated with ethnicity, glaucoma treatment duration, number of medications, BAK use and clinical ocular surface changes, especially SPK.