Evaluation of Tear fluid secretion and Intraocular Pressure in normal Merinos Sheep and Saanen Goats

Abstract

This study aimed at determining the effects of the species, sex and age on normal tear secretion and intraocular pressure (IOP) in normal Merinos sheep and Saanen goats, and assess the effect of topically applied atropine on tear secretions in these species. The study used a total of 80 healthy Merinos sheep, Saanen goats, Merinos lambs and Saanen kids of 20 in each. The sheep and goat aged between 1-2.5 years and the lambs and kits between 15-20 days. The lambs and kits consisted of females and males of equal numbers. Tear secretion and intraocular pressure (IOP) were measured with Schirmer Tear Test (STT) and Schiotz Tonometry, respectively. All measurements were performed prior to and five minutes after the instillation of two-four eye drops of atropine sulfate between 6 and 10 p. m for three consecutive days. The present results demonstrated that with regard to tear secretion and IOP the differences between sheep and lambs, and that between goats and kids were statistically significant (p < 0.001) whereas the differences between the sheep and goats was non-significant (p > 0.05). On the other hand, the values of tear secretion and IOP in the lambs and kids were significantly lower (p < 0.001) than those of sheep and goats. It was determined that sex variation did not significantly influence the IOP and STT values (p > 0.05) but topical atropine administration significantly reduced tear volume (p < 0.001) in all cases.