Retinitis pigmentosa
RP; Vision loss - RP; Night vision loss - RP; Rod Cone dystrophy; Peripheral vision loss - RP; Night blindness
Retinitis pigmentosa is an eye disease in which there is damage to the retina. The retina is the layer of tissue at the back of the inner eye. This layer converts light images to nerve signals and sends them to the brain.
The eye is the organ of sight, a nearly spherical hollow globe filled with fluids (humors). The outer layer or tunic (sclera, or white, and cornea) is fibrous and protective. The middle layer (choroid, ciliary body and the iris) is vascular. The innermost layer (the retina) is nervous or sensory. The fluids in the eye are divided by the lens into the vitreous humor (behind the lens) and the aqueous humor (in front of the lens). The lens itself is flexible and suspended by ligaments which allow it to change shape to focus light on the retina, which is composed of sensory neurons.
A slit-lamp, which is a specialized magnifying microscope, is used to examine the structures of the eye (including the cornea, iris, vitreous, and retina). The slit-lamp is used to examine, treat (with a laser), and photograph (with a camera) the eye.
Causes
Retinitis pigmentosa can run in families. The disorder can be caused by several genetic defects.
The cells controlling night vision (rods) are most likely to be affected. However, in some cases, retinal cone cells are damaged the most. The main sign of the disease is the presence of dark deposits in the retina.
The main risk factor is a family history of retinitis pigmentosa. It is a rare condition affecting about 1 in 4,000 people in the United States.
Symptoms
Symptoms often first appear in childhood. However, severe vision problems do not often develop before early adulthood.
- Decreased vision at night or in low light. Early signs may include having a harder time moving around in the dark.
- Loss of side (peripheral) vision, causing "tunnel vision."
- Loss of central vision (in advanced cases). This will affect the ability to read.
- Loss of color vision
- Sensitivity to bright light
Exams and Tests
Tests to evaluate the retina:
- Color vision
- Exam of the retina by ophthalmoscopy after the pupils have been dilated
- Fluorescein angiography
- Intraocular pressure
- Measurement of the electrical activity in the retina (electroretinogram)
- Pupil reflex response
- Refraction test
- Retinal photography
- Side vision test (visual field test)
- Slit lamp examination
- Visual acuity
Treatment
There is no effective treatment for this condition. Wearing sunglasses to protect the retina from ultraviolet light may help preserve vision.
Some studies suggest that treatment with antioxidants (such as high doses of vitamin A palmitate) may slow the disease. However, taking high doses of vitamin A can cause serious liver problems. The benefit of treatment has to be weighed against risks to the liver.
Clinical trials are in progress to assess new treatments for retinitis pigmentosa, including the:
- Use of DHA, which is an omega-3 fatty acid.
- Treatments related to the possible genetic causes of this disorder
Other treatments, such as microchip implants into the retina that act like a microscopic video camera, are in the early stages of development. These treatments may be useful for treating blindness associated with RP and other serious eye conditions.
A vision specialist can help you adapt to vision loss. Make regular visits to an eye care specialist, who can detect cataracts or retinal swelling. Both of these problems can be treated.
Outlook (Prognosis)
The disorder will continue to progress slowly. Complete blindness is uncommon.
Possible Complications
Peripheral and central loss of vision will occur over time.
People with retinitis pigmentosa often develop cataracts at an early age. They may also develop swelling of the retina (macular edema). Cataracts can be removed if they contribute to vision loss.
When to Contact a Medical Professional
Contact your health care provider if you have problems with night vision or you develop other symptoms of this disorder.
Prevention
Genetic counseling and testing may help determine whether your children are at risk for this disease.
References
American Academy of Ophthalmology website. New treatments for retinitis pigmentosa.
Cioffi GA, Liebmann JM. Diseases of the visual system. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 391.
Cukras CA, Zein WM, Sieving PA. Progressive and 'stationary' inherited retinal degenerations. In: Yanoff M, Duker JS, eds. Ophthalmology. 6th ed. Philadelphia, PA: Elsevier; 2023:chap 6.12.
Gregory-Evans K, Yang P, Pennesi ME. Retinitis pigmentosa and allied disorders. In: Sadda SR, Sarraf D, Freund KB, et al , eds. Ryan's Retina. 7th ed. Philadelphia, PA: Elsevier; 2023:chap 43.
Olitisky SE, Marsh JD. Disorders of the retina and vitreous. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 648.
Version Info
Last reviewed on: 1/29/2024
Reviewed by: Audrey Tai, DO, MS, Athena Eye Care, Mission Viejo, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
