RESUMEN
AIM: To investigate the incidence of oculocardiac reflex (OCR) with two anesthetic regimens and its prevention using topical anesthetics in a rabbit model. We also investigated the effect of topical anesthetics on corneal healing.METHODS: Forty-eight clinically healthy adult New Zealand white rabbits of either sex were divided into two groups (Group A and B) and anesthetized with either ketamine (Group A, n=24) or propofol (Group B, n=24). In this study , the incidence of OCR was recorded in each group with a variety of ocular manipulation with or without the use of topical anesthetics (40g/L lignocaine, 5g/L proparacain, 5g/L bupivacaine). Corneal toxicity and healing following the use of each topical anesthetic was assessed one day after surgery and up to 7 days postoperatively by clinical examination of the eye, histopathology and collagen staining and transmission electron microscopy.RESULTS: No incidence of OCR was recorded with ocular manipulation under ketamine anesthesia, whereas significant reduction in heart rate (P<0.01) was recorded under propofol anesthesia. Topical anesthetics could successfully prevent the OCR without affecting the corneal healing.CONCLUSION: Topical anesthetics may be recommended for prevention of OCR without any local adverse effect.
RESUMEN
AIM: To create a live animal model of cataract for training in phacoemulsification.METHODS: The left eye of each dog was selected, and cataract was induced by puncturing the anterior capsule of the lens with the beveled end of the 26 gauge needle under general anesthesia. Phacoemulsification was performed in all the eyes following development of cataract.RESULTS: Ophthalmologic examination showed posterior cortical opacification started from day 5 to 7 after the induction and the complete cataract formation was observed at 75 days post the induction. The phaco-chop technique was practiced in all the dogs, followed by placement of intraocular lens. Vision was restored in all the dogs following the phacoemulsification.CONCLUSION: Considering the enormous losses caused initially by inexperienced surgeons while performing phacoemulsification, we suppose that this live animal model will be far superior to cadaver eyes that are commonly used for practice of phacosurgery.