Estimating the prevalence of dry eye among Indian patients attending a tertiary ophthalmology clinic

McMonnies' and Ocular Surface Disease Index (OSDI) questionnaires were used to estimate the prevalence of dry eye among 400 consecutive patients aged >40 years attending the ophthalmology outpatient department of the Lady Hardinge Medical College and associated Smt Sucheta Kriplani Hospital, in New Delhi, India. These estimates were then compared with the results of various clinical tests and examinations of the same patients, including Schirmer's tests, evaluations of tear-film breakup times and fluorescein staining of corneas. Although the overall prevalence of dry eye based on OSDI was 29.25%, there was considerable age- and gender-related variation in this parameter. Compared with the younger patients, those aged >or=80 years were more likely to have OSDI that were indicative of dry eye (41.2%), and the women investigated were more likely to have dry eye (as indicated by OSDI) than the men (27% v. 12%). Occupation, however, appeared to have no effect on the risk of dry eye (P=0.952). Grittiness was the commonest complaint reported. McMonnies' indices (MMI), OSDI and the values recorded in Schirmer's tests were all significantly and positively correlated with the probability of a clinical diagnosis of dry eye (P<0.001 for each). Only patients with a Schirmer's value of <8 mm showed fluorescein staining of the cornea (P<0.005). This appears to be the first report from India in which MMI and OSDI have been significantly correlated with the probability of a clinical diagnosis of dry eye. Although the subjects were recruited in an ophthalmology department and may not have been very representative of the general population of New Delhi, dry-eye syndrome is probably common in the study area and probably has a considerable socio-economic impact. The early detection and timely management of this syndrome is important, as they can help prevent long-term sequelae and sight-threatening complications.