George, O. G. and Omokhua, P. O.
This study compared the effects of different topical anaesthetic agents on tear quantity and tear quality. To establish this, 30 subjects aged between 18-35years with mean age 23±2.60years and free from ocular and systemic diseases were used. The study population consisted of 15 males and 15 females. The quantity and quality of tears were measured for each subject before and after instillation of topical anaesthetic agents. The anaesthetic agents used were 2% xylocaine hydrochloride, 0.5% proparacaine hydrochloride and 0.5% tetracaine hydrochloride. Schirmer’s tear test was used to assess the number of tears while tear quality was assessed with Non-InvasiveTearBreak-Up-Time (NITBUT). The result obtained showed that 0.5% proparacaine hydrochloride had a statistically significant decrease in tear quantity produced after instillation, using the one-way analysis of variance, ANOVA (F = 4.43, P< 0.005). 0.5% tetracaine hydrochloride had a statistically significant effect on tear film stability time (F = 16.78, P < 0.005) while 2% xylocaine hydrochloride had the least effect on tear quantity and tear quality. Thus, of these three topical anaesthetic agents, 0.5% tetracaine hydrochloride may be the preferred choice in optometric practice particularly in patients with Keratoconjunctivitis Sicca (KCS) in order to facilitate their tear film stability; while the use of proparacaine should be discouraged in patients with dry eye syndrome.
Keywords: 2% Xylocaine hydrochloride, 0.5% Proparacaine hydrochloride, 0.5% Tetracaine hydrochloride,Tear quality,Tear quantity.