Amaechi, O. U. and Osunwoke, C. M.
Abstract
Tear stability normal to Nigerians with consideration of gender and age has not been reported. Tear stability in young adults was measured using invasive and non-invasive tear break-up time (TBUT and NIBUT). Forty –five subjects aged 20 to 30 years were selected from among the students of the University of Benin, Edo State. NIBUT was measured by noting the time taken for distortion or diffusion or diffusion of the Keratometric mires on the corneal surface while TBUT was assessed by noting the time taken for dry spots to appear on fluorescein treated eye. The mean NIBUT of the sample was 15.3±3.0 seconds and 15.2±3.1 seconds for TBUT. The relation between TBUT and NIBUT was not statistically significant (P>0.05). The difference in mean TBUT and NITBUT was also not significant (P>0.05). There was no significant difference in mean TBUT and NIBUT between males and females (P>0.05). TBUT and NIBUT values were independent of the subject’s age. The TBUT values were comparable to NIBUT values and as such either of the two techniques can assuredly be used to assess the tear film stability. The status of tear stability would help in selecting suitable candidates for contact lens wear.
Keywords: Corneal surfaces, Tear film, Non-invasive tear break-up time (TBUT), Invasive tear break-up time (NIBUT), Stability.