Comparison of Schirmer's test and tear film breakup time test to detect tear film abnormalities in patients with pterygium.

Abstract

OBJECTIVE: To compare tear film breakup time test with Schirmer's test in patients with pterygium. METHODS: The case-control study, involving 86 patients with unilateral primary pterygium aged between 30 and 70 years, was conducted at the Department of Ophthalmology, Karachi Medical and Dental College, Abbasi Shaheed Hospital, from May 2009 to December 2010. The eye with pterygium was taken as the case, and was compared with the other eye without pterygium which was taken as the control in these patients. All patients underwent routine ophthalmic examination. Tear film tests such as Schirmer's test and tear film breakup time test were performed on all these eyes. Results of tear function test between the eyes with pterygium (cases) and the eye without pterygium (control) were compared. SPSS 17 was used for statistical analysis. Chi square test was used for comparing the results of the cases and the controls. RESULTS: Of the 86 patients, 63 (73.3%) were men, while 23 (26.7%) were women. The median age was 41 years. There were 62 (72.1%) patients with pterygium in the right eye, while 24 (27.9%) had it in the left. Among the involved eyes, decreased tear breakup time (<10 seconds) was observed in 65 (75.6%) eyes, while 21 (24.4%) eyes did not show decreased tear breakup time i.e.>10 seconds. On the other hand, 8 (9.3 %) eyes with pterygium had Schirmer's test positive and 78 (90.7 %) eyes had it negative. CONCLUSION: Tear film breakup time test has better diagnostic value compared to Schirmer's test in detecting tear film abnormality in patients with pterygium.