Image supplied by Sheree Goodall, Specsavers Whangarei, NZ
Retinitis pigmentosa is a rare inherited / genetic condition that occurs due to a progressive loss of rod and sometimes cone photoreceptor cells of the retina.
Early onset of the disease can occur within the first few years of life, while some patients only exhibit ocular signs and have symptoms in early adulthood. Retinitis pigmentosa can occur alongside other systemic diseases, or neurosensory disorders or developmental abnormalities.
Symptoms include difficulty with vision at night, difficulty with vision adapting from dim to bright environments and vice versa, and progressive loss of peripheral vision. It is common for these symptoms to occur in each eye at a similar rate and symmetrically. In situations where cone photoreceptors are affected, patients may experience a reduction in visual acuity or changes to colour vision.
Retinitis pigmentosa has classic clinical signs that include:
- Bone spicule pigment and/or pigment clumping that often appears first in the mid-peripheral retina
- Attenuation of the arterioles
- Waxy, pale appearance of the disc.
Clinical diagnostic tests such as electroretinograms, visual field testing and genetic testing are often requested by an ophthalmologist in order to further investigate before a diagnosis is made.
As there is no treatment for retinitis pigmentosa, it generally progresses to cause significant loss of peripheral vision and less commonly, can result in complete loss of vision. Management for the condition involves regular visual examination to monitor for progression, referral to a low vision service for holistic management for quality of life, and visual aids.