Evaluation of ropivacaine solution intraocular administration safety in the experiment
Intrachamber anesthesia is an effective method used in cataract phacoemulsification and is practically devoid of complications. A serious disadvantage of this method is the toxic effect of the anesthetic on the posterior corneal epithelium. PURPOSE: To study a 0.75% ropivacaine solution safety for the posterior epithelium of the cornea, retina, ciliary body of the rabbit eyes in the experiment. METHODS: During experiment 1, 20 rabbits (40 eyes) were injected intracamerally with a 0.75% ropivacaine solution, 1% lidocaine solution, and saline solution as a control. We dynamically evaluated the eye globe structures using biomicroscopy, ophthalmoscopy, pachymetry and specular microscopy. Experiment 2 included 14 rabbits (28 eyes). In the course of experiment 2, several rabbits (7 eyes) were intracamerally injected with 0.75% ropivacaine solution. Other animals (7 eyes) had the solution administered intracamerally and intravitreally. Control group underwent intracameral and intravitreal injections of saline solution. Biomicroscopy and ophthalmoscopy were performed. On the 7th day, the eye globes were enucleated and examined morphologically. RESULTS: During experiment 1 biomicroscopy and ophthalmoscopy did not detect any inflammatory, toxic and allergic changes. Pachymetry and mirror microscopy showed no statistically relevant changes in central corneal thickness and corneal endothelium cell count correspondingly. Experiment 2 revealed biomicroscopical and ophthalmoscopical inflammatory changes in the ciliary body on the first day after intracameral and intravitreal injections of 0.75% ropivacaine solution and saline. By day 7 the manifestations ceased. Histological study of intraocular structures detected no changes after ropivacaine solution injection. CONCLUSION: The experiments proved the safety of intracameral and intravitreal 0.75% ropivacaine solution injections for the rabbit intraocular structures.