Concordance between common dry eye diagnostic tests

Aim: Large variations in results of diagnostic tests for mild to moderate dry eye are widely recognised. The purpose of this study was to assess if there was concordance between common dry eye diagnostic tests. Methods: A total of 91 subjects were recruited to the study. The tear film and ocular surface were evaluated using the phenol red thread test (PRT), tear film break-up time (TBUT), biomicroscopic examination and impression cytological assessment of conjunctival goblet cells. Dry eye symptoms were assessed using McMonnies' dry eye questionnaire (MQ) and statistical correlations between all tests were assessed. Results: This study cohort did not include severe aqueous deficient dry eye patients as determined by the PRT. A statistically significant difference was noted between PRT results and all other tests (p <= 0.001). Only Meibomian gland pathology, MQ, reduced goblet cell density and TBUT (<= 7 s) demonstrated correlation determined by McNemar's test. Conclusion: A correlation was found only between tests assessing lipid/mucous deficiency (Meibomian gland evaluation, goblet cell density, TBUT and MQ).