Validity of subjective assessment as screening tool for dry eye disease and its association with clinical tests.

Abstract

To determine the role of subjective assessment using McMonnies dry eye questionnaire in diagnosing dry eye disease and its association with clinical tests. There were 500 patients screened for dry eye using McMonnies dry eye questionnaire between May to October 2013 at the outpatient Department of Ophthalmology of a medical college hospital. All 500 patients were subjected to clinical tests. Dry eye was defined as having one or more symptoms often or all the time. Positive signs were if one or both eyes revealed tear film breakup time (TBUT) of ≤10s, a Schirmer test score of ≤10 mm, a Rose Bengal staining score of ≥1, a Lissamine green staining score of ≥1 or existence of meibomian gland disease (≥grade 1). Statistical analysis was performed to describe the distribution of symptoms and signs, to assess the correlations between McMonnies score (MS) and variable clinical signs of dry eye, and to explore the association between dry eye symptoms and variable clinical signs. Analysis was performed using software package Epi info. A Probability (P) value using Chi-square test of <0.005 was taken as significant. Dry eye prevalence with symptoms (questionnaire), Schirmer test, TBUT, Rose Bengal staining and Lissamine green staining was 25.6%, 15.20%, 20.80%, 23.60%, and 22.60% respectively. Among those with severe symptoms (MS>20), 75.86% had a low TBUT (<10s), 58.62% had a low Schirmer's I test (≤10 mm), 86.20% had Rose Bengal staining score of ≥1, 79.31% had Lissamine green staining score of ≥1. We found statistically significant associations between positive Schirmer test and arthritis (P<0.002), dryness elsewhere (P<0.001), contact lens use (P<0.002), systemic medication (P<0.0001), sleeping with eyes partly open (P<0.002), history of dry eyes treatment (P<0.0001), environmental factors (P<0.001), swimming (P<0.001). Subjective assessment plays an important role in diagnosing dry eye disease. There is strong correlation between MS and Schirmer test, TBUT, Rose Bengal staining and Lissamine green staining in normal as well as marginal and pathological dry eye.