Progressive retinal atrophy in the Abyssinian cat: an update
Narfström, L.K.; Nilsson, S.E.
Veterinary Record 112(22): 525-526
1983
ISSN/ISBN: 0042-4900 PMID: 6879965 Document Number: 212304
Of 220 Abyssinian cats examined throughout Sweden, 78 had progressive retinal atrophy. Most of the affected cats showed clinical signs of bilateral generalized retinopathy between 1.5-2 years of age. The disease was progressive but the time course varied between animals. Advanced retinal atrophy developed between 3-6 years of age. Ophthalmoscopy at early stages of the disease showed greyish discolouration and slight attenuation of the blood vessels, while at the more advanced stages there was hyperreflectivity of the tiapetal fundus, severe attenuation of blood vessels, depigmented areas and areas of focal pigmentation. Fluorescein angiography showed attenuation of blood vessels only at the moderately advanced and advanced stages of the disease. Electroretinograms (ERG), including both fast and slow potentials, were reduced in cats, known to inherit the disease, before retinal abnormalities had developed. A flat ERG was recorded in a cat with advanced atrophy. Light and electron microscopy revealed that the photoreceptor cell layer was primarily affected. There was great variation in involvement of different areas of the fundus as well as rates of progression. At early stages the more peripheral parts of the fundus were most severely affected. Both tapetal and nontapetal fundus were affected.