Disorder - Rod-cone dysplasia

Organ Systems Involved
Nervous/sensory

Alternative disorders described within LIDA

Retinal dystrophy; Progressive retinal atrophy (PRA); Type I progressive retinal degeneration; Autosomal dominant retinitis pigmentosa in humans

Alternative Names
Autosomal dominant retinal dystrophy; Photoreceptor dysplasia

Presenting Signs

Rods and cones are the cells in the retina, the lining at the back of the eye, that receive the light that enters the eye. Affected cats have abnormally developed rods and cones within the retina. These abnormal cells degenerate early in life. Common symptoms of rod-cone dysplasia include slow or absent pupillary light reflexes. This means that the pupil does not contract in strong light as it normally should. Other symptoms are night blindness (when rods are affected) and/or day blindness (when cones are affected). Owners may notice that affected cats are more anxious and careful in low light, or have an impaired vision during the day. Affected cats at two to three weeks tend to show pupil dilation; at four to five weeks vision is usually impaired and an intermittent rotatory nystagmus – an involuntary eye movement – is present. Retinal degeneration and subsequent night blindness occurs at eight weeks. Cats with rod-cone dysplasia will eventually become completely blind.

The abnormalities are almost always present in both eyes, which deteriorate at approximately the same rate.

Breeds Affected
Abyssinian
Persian


Treatment

None: there is no available therapy surgically or medically. This disease, however, can be managed quite well in a cat's familiar environment. Cats that have become blind may require direct supervision when exposed to a potentially hazardous environment.

PubMed References
Rod-cone dysplasia

Contributor
Findy Au