Retinal detachment in the pheasant (Phasianus colchicus)

Retinal detachment was observed as a cause of blindness in small numbers of reared pheasants in widely separated geographical areas. Lesions were bilateral but asymmetrical in 16 birds. In three pheasants only one eye was affected. Clinical signs were first noticed at 5 weeks of age. Affected birds were blind by the time they were mature. Early lesions comprised subretinal fluid and degeneration of the vitreous body. Following separation of the retina at the junction of the pigmented epithelium and photoreceptors, adhesions took place between the detached tissue and both the pecten and lens. Peripheral cystoid defects were seen concomitantly in the retinas of seven pheasants but these were bilateral in only two individuals. The cause of the disease is unknown.