Intraocular pressure measurement in the conscious rat

Purpose. To develop a method for measurement of intraocular pressure in conscious, unsedated rats. Methods. The animal was gently held with a thick fabric mitten, topical anesthetic drops were instilled and the Tone-Pen was applied to the cornea. Result. Measurements in a total of 51 animals did not differ significantly among four strains studied: the overall mean intraocular pressure+/-standard deviation was 13.0+/-1.2 mm Hg. Several intraocular pressure tolerance limits were calculated from this conscious rat data to provide a baseline estimate for future studies. Conclusions. This measurement method in conscious rats may contribute to making this widely used laboratory animal available for intraocular pressure research.