What is retinitis pigmentosa?
Retinitis pigmentosa is actually the name given to a group of hereditary eye disorders, all of which involve the eye's retina (the light-sensitive nerve layer that lines the back of the eye). All of these disorders cause a gradual, yet progressive, loss or reduction in visual ability.
The following are the most common symptoms of retinitis pigmentosa. However, each individual may experience symptoms differently, especially with severity and progression as the most obvious variables. Some people with retinitis pigmentosa experience a slow, very progressive loss of vision, while others lose their visual ability much more quickly and severely. Other common symptoms may include:
- Difficulty seeing in poor light (for example, at dusk or in a dimly lit area) or in the dark
- A diminished visual field, either central vision (a condition called macular dystrophy) or peripheral vision (sometimes referred to as tunnel vision)
- Difficulty reading print (with a loss of central vision)
- Difficulty deciphering detailed images (with a loss of central vision)
- Difficulty with stumbling or tripping over objects not seen; clumsiness (with a loss of peripheral vision)
The symptoms of retinitis pigmentosa may resemble other eye diseases. Consult a doctor for diagnosis.
Retinitis pigmentosa is caused by a variety of different inherited retinal defects, all of which affect the ability of the retina to sense light. The retinal defect may be found in the retina's rod cells (a type of retinal cell found outside of the central portion of the retina that help to transmit dim light and allow for peripheral vision), the retina's cone cells (a type of retinal cell found inside the center of the retina that help to transmit the color and detail of images), and/or in the connection between the cells that compose the retina.
How is it diagnosed?
In addition to a complete medical history and eye examination, your eye care professional may perform one or more of the following tests to determine how much of the retina is diseased:
- Visual acuity test (the common eye chart test measures vision ability at various distances)
- Ophthalmoscopy (a doctor performs a detailed examination of the retina using a special magnifying glass)
- Refraction test
- Color defectiveness determination test
- Retinal examination
- Ultrasound of the eye