Comparative Analysis Of The Effects Of Topical Anaesthetic Agents On Tear Quantity And Tear Quality

Abstract

This studycompared the effects of different topical anaesthetic agents on tear quantity andtear quality. To establishthis, 30 subjects agedbetween18-35yearswithmeanage 23±2.60years andfree fromocular and systemic diseaseswere used.The study population consisted of 15males and15females.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 quantity of tears while tear qualitywas assessedwithNon-InvasiveTear Break-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 filmstability 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.