Retinitis Pigmentosa Symptoms and Signs
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 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.
Retinitis pigmentosa facts
- Retinitis pigmentosa is a bilateral inherited condition that involves both eyes.
- It usually starts later in life and progresses to blindness.
- Low-vision rehabilitation provides some help in coping with the condition, but there is no treatment or cure at this time.
What is retinitis pigmentosa?
Retinitis pigmentosa is the most common of a group of hereditary progressive retinal degenerations or dystrophies. There is considerable variation and overlap among the various forms of retinitis pigmentosa. Common to all of them is progressive degeneration of the retina, specifically of the light receptors, known as the rods and cones. The rods of the retina are involved earlier in the course of the disease, and cone deterioration occurs later. In this progressive degeneration of the retina, the peripheral vision slowly constricts and central vision is usually retained until late in the disease.
What causes retinitis pigmentosa?
Retinitis pigmentosa is an inherited condition which involves both eyes. If it starts in one eye, the other eye usually develops the same condition in a number of years. Most cases are familial, inherited in a variety of ways, including dominant, recessive, and sex-linked recessive. Some cases are sporadic and lack a family history of the disease. A thorough genetic pedigree, often with the aid of a genetic counselor, is essential in determining risk of future generations acquiring the disease.
Retinitis pigmentosa is usually diagnosed during the teenage years but may be present at birth. The latter congenital type is usually fairly stable and nonprogressive. Cases that are diagnosed later in life are often milder and may progress more slowly.
RP is sometimes associated with other systemic illnesses. Usher syndrome, characterized by retinitis pigmentosa and neural hearing loss, is the most common cause of deaf-blindness in the United States. The hearing loss usually is diagnosed earlier than the eye changes.