Retinitis Pigmentosa (cont.)
Frank J. Weinstock, MD, FACS
Dr. Weinstock is a board-certified ophthalmologist. He practices general ophthalmology in Canton, Ohio, with a special interest in contact lenses. He holds faculty positions of Professor of Ophthalmology at the Northeastern Ohio Colleges of Medicine and Affiliate Clinical Professor in the Charles E. Schmidt College of Biomedical Science at Florida Atlantic University.
Andrew A. Dahl, MD, FACS
Andrew A. Dahl, MD, is a board-certified ophthalmologist. Dr. Dahl's educational background includes a BA with Honors and Distinction from Wesleyan University, Middletown, CT, and an MD from Cornell University, where he was selected for Alpha Omega Alpha, the national medical honor society. He had an internal medical internship at the New York Hospital/Cornell Medical Center.
In this Article
- Retinitis pigmentosa facts
- What is retinitis pigmentosa?
- What causes retinitis pigmentosa?
- What are retinitis pigmentosa symptoms and signs?
- How is retinitis pigmentosa diagnosed?
- What is the treatment for retinitis pigmentosa?
- How long does retinitis pigmentosa last?
- What are complications of retinitis pigmentosa?
- What is the prognosis for retinitis pigmentosa?
- What research is being done for retinitis pigmentosa?
- Where can I find out more information about retinitis pigmentosa?
- Find a local Doctor in your town
What are retinitis pigmentosa symptoms and signs?
Since retinitis pigmentosa begins as rod degeneration, the patient first notices increasing difficulty in night vision, followed by difficulty seeing in the periphery. Slowly progressive constriction of the visual field leads to tunnel vision. A small area of central vision in both eyes usually persists for years. Generally night blindness precedes tunnel vision by years or even decades. Total blindness eventually ensues in most cases. The age of appearance of legal blindness ranges from as early as childhood to as late as the 40s.
How is retinitis pigmentosa diagnosed?
- Decreased vision at night or in low light
- Loss of side (peripheral) vision
- Loss of central vision (in advanced cases)
Although the history (especially the possibility of retinitis pigmentosa appearing in other family members) and complaints of the patient may make one suspect RP, it is primarily diagnosed by examination. The patient may complain of difficulty seeing at night or in low light condition. At some point, the ophthalmologist observes relatively characteristic clumping of pigment in the retina in a pattern described as resembling bone spicules. Fundus examination (looking at the back layers of the eye with the ophthalmoscope, an instrument allowing the visualization of the back of the eye by looking through the pupil) affords the view of the retina. A similar pattern may appear in congenital syphilis which is unrelated and must be distinguished.
Two tests are essential in the diagnosis and the follow-up exams.
Visual field testing will find defects in the peripheral (side vision) with the degree of loss related to defects in relation to the damage occurring in this disease. Over time, the visual field may reduce to a small central island of vision causing "tunnel vision." The final progression may be the complete loss of the remaining central vision.
Electrophysiological testing by the ophthalmologist (often by referral to a university ophthalmology department, since very few private offices would have this equipment) is often diagnostic. Responses to flashes of light are measured via electrodes placed on the surface of the eye. It is a painless test. The electroretinogram (ERG), in conjunction with the visual field exam, will usually make the diagnosis. This will also determine if there is any cone involvement.
Recently, gene testing for defects is being done to clarify the basic cause for RP and assist in ultimately finding a treatment.
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