title: An animal model of visual loss from orbital hemorrhage.
abstract: Intraorbital hemorrhage may arise spontaneously or following orbital or periorbital surgery or trauma and may be associated with visual loss or impairment. This project was designed to evaluate the ophthalmic effects and underlying mechanism(s) associated with visual impairment secondary to intraorbital hemorrhage. An experimental surgical procedure was developed to simulate intraorbital hemorrhage. A reversible state of unilateral visual loss secondary to acutely increased intraorbital volume was induced and maintained under general anesthesia for either 90, 120, or 180 min duration in nine adult nonhuman primates (NHPs) (Macaca arctoides). Color funduscopic photography, i.v. fluorescein angiography, electrophysiological testing, and tonometry were obtained during baseline, experimental, and follow-up procedures. The globes and optic nerves were obtained for histopathologic evaluation. One of three animals in the 180 min experimental group exhibited clinical and histopathological changes of optic neuropathy 6 weeks after the experimental procedure. Optic neuropathy is one of several proposed etiologies for producing visual loss secondary to intraorbital hemorrhage. This study offers a reliable, safe, and reversible technique to study the effects of acutely increased intraorbital volume in nonhuman primates. The animal model described may be useful for evaluating mechanism(s) involved with visual impairment in other acquired optic neuropathies.
authors.affiliation: Department of Comparative Medicine, Penn State University College of Medicine, Hershey 17033.
authors.forename: D G
authors.initials: DG
authors.lastname: Schabdach
authors.forename: S H
authors.initials: SH
authors.lastname: Goldberg
authors.forename: M E
authors.initials: ME
authors.lastname: Breton
authors.forename: J W
authors.initials: JW
authors.lastname: Griffith
authors.forename: C M
authors.initials: CM
authors.lastname: Lang
authors.forename: D
authors.initials: D
authors.lastname: Cunningham
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004596:Electroretinography; D005130:Eye Hemorrhage / Q000150:complications* / Q000503:physiopathology; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D007429:Intraocular Pressure; D008251:Macaca; D008297:Male; D009901:Optic Nerve Diseases / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D009916:Orbital Diseases / Q000150:complications* / Q000503:physiopathology; D014786:Vision Disorders / Q000209:etiology* / Q000503:physiopathology