Retinitis Pigmentosa

What's going on?

This is a dystrophy of the retina. The rods responsible for peripheral and night vision gradually deteriorate. Night vision is impaired and the patient's visual fields gradually constrict. This is a hereditary condition, inherited either recessively or dominantly. It may also be sporadic.

The retinal pigment epithelium reacts to the dysfunctional rods by releasing pigment clumps that give the retina its 'bone spiculed' appearance (resembling the spicules seen on light microscopy of the bone). The blood vessels become attenuated and the disc is pale.

If I examine the patient, what will I find?

Reduced field of vision. Bone-spicule pigmentation in the peripheral retina, sparing the macula, as well as a pale disc and attenuation of the blood vessels.

Progression is variable, but if the patient has a severe condition the vision can deteriorate rapidly.

What if I've diagnosed it?

Refer routinely.

What will the hospital do?

Diagnosis may be made by testing the electrical impulses generated by the retina. The patient is counselled and usually informed of the likely prognosis.

What to tell the patient

This condition is unfortunately progressive, but the degree of vision lost and the speed at which it happens varies between patients. Generally, the younger the age at which the patient notices symptoms, the more severe the vision loss will be. There are support groups for people with retinitis pigmentosa throughout the country.

Problems that may arise, and how to deal with them

These patients are also at risk of developing cataract and open-angle glaucoma, for which they may need referral if they not still under follow-up.