What is retinitis pigmentosa?
What are the symptoms of retinitis pigmentosa?
Retinitis pigmentosa involves the loss of sensory cells in the retina, starting with the so-called rods, and followed later by the cones. This causes the increasing loss of retinal function, which leads to the typical vision impairment, including, for example:
- Gradual narrowing of the visual field, ending in tunnel vision
- Restricted ability to see in twilight or at night
- Glare sensitivity
- Impairments of contrast and colour vision
The type of symptoms and their sequence and severity depend on the areas of the retina that are affected by the loss of sensory cells.
What is the course of retinitis pigmentosa?
Typical for RP is a slow, sometimes staged, but steady progression. Systematic examinations show an exponential decrease of the visual field. On average, the remaining visual field of an RP patient decreases by half every 4-5 years.
Most people affected by RP realise this already at an early age, for example through night-blindness, in which the vision in low light and darkness are strongly impaired. Night-blindness is related to the early degeneration of the rods, the photoreceptor cells in the retina responsible for low-light vision.
Although in retinitis pigmentosa the rods are affected first, the disease will spread to the cones as it progresses further. These are responsible for colour vision and contrast distinction. When the cones start to become affected, this leads to impairment of colour vision of blue and yellow tones in the first instance. At the same time the contrast distinction is deteriorating with dark areas appearing overly bright. This contributes to an increased glare-sensitivity.
In the final stage of the disease, those affected can go completely blind. There are currently no therapies available to prevent and cure retinitis pigmentosa. Several so-called neuroprotective strategies are being researched to combat the degeneration of photoreceptors and other cells of the retina and to limit the loss of vision4.
The therapy of transcorneal electrical stimulation (TES) aims at slowing down the decrease of the visual field by electrical stimulation of the retina.
- Retinitis pigmentosa. Online-Information der PRO RETINA Deutschland e.V. www.pro-retina.de/netzhauterkrankungen/retinitis-pigmentosa/krankheitsbild
- Verbakel SK, van Huet RAC, Boon CJF, den Hollander AI, Collin RWJ, Klaver CCW, et al. Non-syndromic retinitis pigmentosa. Prog Retin Eye Res. 2018;66:157-86.
- Massof RW, Finkelstein D. A Two-stage Hypothesis for the Natural Course of Retinitis Pigmentosa. Advances in the Biosciences. 1987;62:29-58.
- Pardue MT, Allen RS. Neuroprotective strategies for retinal disease. Prog Retin Eye Res. 2018;65:50-76