Intraocular pressure measurements in a rat glaucoma model

The main objective of this study was to determine if consistent intraocular pressure (IOP) measurements could be obtained from an in vivo Long Evans rat glaucoma model. An increase in IOP is the primary risk factor associated with glaucoma and reliable IOP measurements would validate our in vivo glaucoma model that we are inducing in rats. The study used nine Long Evans rats. Three rats severed as controls, three received surgery to induce glaucoma and three were administered PNU-282987 neuroprotective eye drops and then surgery to induce glaucoma. IOP measurements were obtained by tapping the retina of the rat eye through use of a Tono-Lab. Theoretically, IOP should have increased in six of the nine rats, since the surgery created scar tissue and decreased the efficiency of the aqueous drainage system of the eye. The results of this study were somewhat inconclusive in obtaining reliable IOP measurements but are promising. Significant differences were found between the experimental groups and internal controls as well as the control group. In order to claim significantly reliable results, there should not be statistical significance in the control group. This study recommends that future techniques used to obtain consistent IOP measurements should include, longer training periods, increase the number of IOP measurements taken at one time and disregard the first few readings until consistency is observed. This overall significance of this study reveals how future experiments may obtain reliable IOP measurements to validate the surgical procedure of inducing glaucoma.