Abstracts: 39th Annual Meeting of the American College of Veterinary Ophthalmologists, Boston, MA, USA, October 15–18, 2008

Abstract

Purpose: The aim of this study was to evaluate the ocular features and intraocular pressure (IOP) in adult Red Drum Fish (Sciaenops ocellatus). Methods: All fish were anesthetized with tricaine methanesulfonate (MS-222, Western Chemicals, Ferndale, WA, USA) at 70 parts per million. The anterior segment of all fish eyes were examined with a Finnoff transilluminator and slit-lamp biomicroscopy. Binocular indirect ophthalmoscopy was performed in all eyes to observe the posterior segment. IOP was measured and recorded in both eyes of 13/18 fish and in the right eye only in 1/18 fish using applanation tonometry (27/36 total eyes). Tonometry readings were discarded in 4 fish (8 eyes) due to poor anesthesia and inadequate restraint. The horizontal corneal diameter was measured in all eyes. Results: There were 9 male and 9 female fish, all of which were 5 years old. Ophthalmic examination of the anterior segment revealed a horizontal oval-shaped immobile pupil. A characteristically large spherical lens and shallow anterior chamber often exhibiting an aphakic crescent medially was observed. The retina was anangiotic and the fundus ranged in color from white-gray to dark yellow-gray. The optic nerve papilla was horizontally elongated and associated with a prominent hyaloid vessel projecting anteriorly into the vitreous. In 2/36 eyes, 2 mm white translucent cysts in the anterior chamber were identified. Seventeen of the fish had anterior subcapsular opacities in both eyes. These lens opacities were between 1 and 5 mm in diameter and ranged in density from faint to prominent. The subcapsular opacities were central to paraxial. One eye had multifocal lens opacities. The mean horizontal corneal diameter of both eyes was 20.83 ± 1.42 mm. The mean IOP for the right and left eye of fish was 8.69 ± 3.29 mmHg and 6.82 ± 3.19 mmHg, respectively. Mean fish length was 99.05 ± 4.33 cm. Conclusions: The ocular features of a group of adult Red Drum Fish were identified. In this population of red drum, anterior subcapsular cataracts were a common finding. The average IOP this population of fish was determined to be 7.82 ± 2.82 mmHg.