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, doubleblinded 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 thirtytwo 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. Keywords: Keymessage:This study 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.

Comparative assessment of tear function tests, tear osmolarity, and conjunctival impression cytology between patients with pterygium and healthy eyes

“…It follows that the tear film quantitation is changed in the pterygium eyes. Onkar et al[21] also demonstrated that the TMH, measured using OCT, was significantly lower in eyes with pterygium than in control eyes. They reported that 90.2% of pterygium eyes showed abnormal TMH, which was a higher proportion than in our study, although they considered a TMH value <0.3 mm, rather than <0.22 mm, to be abnormal, so the different result was likely due to the cutoffs used to define abnormal TMH.…”

The Effect of Age and Gender on Tear Film Breakup Time

“…After several blinks, the patient avoids blinking and the tear film is examined using a broad-beam of slit lamp with a cobalt blue filter. (4) Tear Breakup Time (TBUT) is the time interval between a complete blink and the appearance of the first break, discontinuity or dry spot observed in the tear film. (5) TBUT less than 10s suggest an abnormal tear film (6) , with values of 5s to 10s, considered marginal, and less than 5s, indicative of dry eye symptoms.…”