Tear and Pterygium: A Clinico-Pathological Study of Conjunctiva for Tear Film Anomaly in Pterygium

Abstract

Aims: To evaluate the clinical and histological status of tear film in patients with unilateral pterygium. Settings and Design: Cross-sectional, case-control, double-blinded study. Methods and Material: Cross-sectional study of both eyes of 102 patients with unilateral pterygium was conducted between March 2011 to December 2012. Patients were subject to fluorescein lower tear meniscus height (LTMH) evaluation, fluorescein tear break-up time (TBUT), Schirmer’s test (using topical anesthetic), vital staining (viz. fluorescein, Rose Bengal and lissamine staining), LTMH imaging with anterior segment spectral-domain optical coherence tomography (OCT) cornea-anterior module (CAM-L and CAM-S), and conjunctival smear impression cytology. The normal eye acted as control. Statistical analysis used: fisher’s t-test and chi-square test. Results: The study comprised of seventy males and thirty-two females in the age-range 28-76years. The mean fluorescein LTMH, mean TBUT, mean Schirmer’s test value, mean OCT CAM-S and CAM-L values in the normal control eyes were 0.36 ± 0.03 mm, 12.3 ± 1.9s, 13.4 ± 2.5 mm, 0.338 ± 0.082 mm and 0.325 ± 0.088 mm, respectively. The comparable values in eyes with pterygium were 0.24 ± 0.03 mm, 8.2 ± 1.4 sec, 9.2 ± 2.4 mm, 0.212 ± 0.046 mm and 0.204 ± 0.058 mm respectively. Goblet cell count was decreased in impression cytology. Conclusions: Both fluorescein and OCT LTMH were found to be significantly decreased (p<0.01) in eyes with pterygium compared to control eyes. Goblet cell count, TBUT and Schirmer’s test values were also comparatively decreased. This study thus emphasizes that tear film abnormalities play a role in aetiology of pterygium and hence early institution of therapy for tear film stabilization can help prevent the disease.