Ophthalmic examination findings and intraocular pressures in wild-caught African giant pouched rats (Cricetomys spp.).

Abstract

PURPOSE: To report ophthalmic examination findings and intraocular pressures (IOPs) in wild-caught African giant pouched rats (Cricetomys ansorgei and gambianus) from Tanzania and Ghana. PROCEDURES: After being placed under general anesthesia for examination, slit-lamp biomicroscopy before and after pharmacologic mydriasis and indirect ophthalmoscopy was performed. Eyes were fluorescein stained and IOPs measured by rebound tonometry using the TonoVet. RESULTS: Thirty-two sexually mature pouched rats (64 eyes) were examined, including 16 males and 16 females. The mean IOP (± standard deviation) was 7.7 (±2.9) mmHg. Fluorescein staining was negative in all eyes. One or more ocular abnormalities were detected in 21 pouched rats (35 eyes). These ocular lesions included the following: lens opacities (n = 23 eyes), persistent pupillary membranes (n = 5), chorioretinal scarring (n = 3), corneal vascularization (n = 2), palpebral margin defect with focal trichiasis (n = 2), phthisis bulbi (n = 1), and posterior synechiae (n = 1). Lens opacities included incipient anterior cortical opacities (n = 7), immature cataract (n = 6), incipient nuclear opacities (n = 5), punctate pigment on anterior lens capsule (n = 2 eyes), incipient suture tip opacities (n = 2), and hypermature cataract (n = 1). CONCLUSIONS: Ocular abnormalities were common in the evaluated population of giant pouched rats; however, most of the detected lesions were mild and believed to have minimal impact on vision. Rebound tonometry with the TonoVetwas a reliable and simple technique to measure IOPs in the anesthetized pouched rats.