| Retinitis pigmentosa | |
|---|---|
| Other names | Inherited retinal dystrophy/diseases |
 | |
| Back of the eye of a person with mid-stage retinitis pigmentosa. Note pigment deposits in the mid periphery along with retinal atrophy. While the macula is preserved there is some loss of pigmentation around it. | |
| Specialty | Ophthalmology, Optometry |
| Symptoms | Trouble seeing at night, decreased peripheral vision[1] |
| Usual onset | Childhood[1] |
| Causes | Genetic[1] |
| Diagnostic method | Eye examination[1] |
| Treatment | Low vision aids, portable lighting, orientation and mobility training[1] |
| Medication | Disulfiram, vitamin A palmitate[1] |
| Frequency | 1 in 4,000 people[1] |
Retinitis pigmentosa (RP) is a member of a group of genetic disorders called inherited retinal dystrophy (IRD) that cause loss of vision.[1] Symptoms include trouble seeing at night and decreasing peripheral vision (side and upper or lower visual field).[1] As peripheral vision worsens, people may experience "tunnel vision".[1] Complete blindness is uncommon.[2] Onset of symptoms is generally gradual and often begins in childhood.[1][2]
Retinitis pigmentosa is generally inherited from one or both parents.[3] It is caused by genetic variants in nearly 100 genes.[3] The underlying mechanism involves the progressive loss of rod photoreceptor cells that line the retina of the eyeball.[1] The rod cells secrete a neuroprotective substance (rod-derived cone viability factor, RdCVF) that protects the cone cells from apoptosis. When these rod cells die, this substance is no longer provided. This is generally followed by the loss of cone photoreceptor cells.[1] Diagnosis is through eye examination of the retina finding dark pigment deposits caused by the rupture of the underlying retinal pigmented epithelial cells, given that these cells contain melanin.[1] Other supportive testing may include the electroretinogram (ERG), visual field testing (VFT), ocular coherence tomography (OCT) and DNA testing to determine the gene responsible for a person's particular type of RP.[1]
There is currently no cure for retinitis pigmentosa.[2] Efforts to manage the problem may include the use of low vision aids, portable lighting, or orientation and mobility training.[1] Vitamin A palmitate supplements may be useful to slow progression.[1] A visual prosthesis may be an option for people with severe symptoms.[1]
There is only one FDA-approved gene therapy that is commercially available to RP patients with Leber congenital amaurosis type 2. It replaces the miscoded RPE65 protein that is produced within the retinal pigmented epithelium. It has been found to be effective in approximately 50% of the patients who receive the therapy. The earlier a child receives the RPE65 therapy, the better their chances are for a positive outcome. There are many other therapies being researched at this time, with the goal of being approved in the next few years.
It is estimated to affect 1 in 4,000 people.[1]
- ^ a b c d e f g h i j k l m n o p q r s "Facts About Retinitis Pigmentosa". National Eye Institute. May 2014. Archived from the original on 7 March 2019. Retrieved 18 April 2020.
- ^ a b c Openshaw A (Feb 2008). Understanding Retinitis Pigmentosa (PDF). University of Michigan Kellogg Eye Center. Archived from the original (PDF) on 2017-08-29. Retrieved 2017-12-02.
- ^ a b "OMIM Entry: Retinitis Pigmentosa". Online Mendelian Inheritance in Man. Retrieved 18 July 2023.