Retinitis Pigmentosa (RP)
CMV retinitis is a serious eye infection of the retina, the light-sensing nerve layer that lines the Retinitis pigmentosa (RP) describes a group of related diseases that tend to run in families and cause a slow but progressive loss of vision. RP affects the rods and cones of the retina, the light-sensitive nerve layer at the back of the eye, and results in a decline in vision in both eyes. RP usually affects both eyes equally with severity ranging from no visual problems in some families to blindness at birth in others. RP gets its name from the fact that one of the symptoms is a clumping of the retinal pigment that can be seen during an eye exam.
The earliest symptom of retinitis pigmentosa, usually noticed in childhood, is night blindness or difficulty with night vision. People with normal vision adjust to the dark quickly, but people with night blindness adjust very slowly or not at all. A loss of side vision, or tunnel vision, is also common as RP progresses. Unfortunately, the combination of night blindness and the loss of peripheral vision can be severe and lead to legal blindness in many people.
While there is a pattern of inheritance for RP, 40% of RP patients have no known previous family history. Learning more about RP in your family can help you and your ophthalmologist predict how RP will affect you.
Usher’s syndrome, in which a person is both deaf and blind, can be associated with RP. The incidence of Usher’s syndrome is difficult to determine but surveys of patients suggest up to 10% of RP patients are deaf. The incidence of Usher’s syndrome is three cases per 100,000. It is the most frequent cause of combined deaf-blindness in adults.
Considerable research is being done to find the hereditary cause of RP. As hereditary defects are discovered it may be possible to develop treatments to prevent progression of the disease. While developments are on the horizon, particularly in the area of genetic research, there is currently no cure for retinitis pigmentosa.
Nutritional supplements may have an effect on RP. It has been reported that Vitamin A can slow the progression of RP. Large doses of Vitamin A are harmful to the body and supplements of Vitamin E alone may make RP worse. Vitamin E is not harmful if taken with Vitamin A or in the presence of a normal diet. Your ophthalmologist can advise you about the risks and benefits of Vitamin A and how much you can safely take.
Despite visual impairment, people with RP can maintain active and rewarding lives through the wide variety of rehabilitative services that are available today. Until there is a cure, periodic examinations by your ophthalmologist will keep you informed of legitimate scientific discoveries as they develop.
Retinoblastoma, a malignant tumor that grows in the retina, the layer of light-sensing cells in the back of the eye, can destroy a child’s vision and be fatal. Affecting children of all races, boys and girls equally, retinoblastoma occurs in one or both eyes, usually in the first year or two of life.
The most common sign is a change in the color of the pupil, which can appear white in reflected light. This phenomenon is referred to as a cat’s eye reflex. Sometimes the affected eye will cross or turn outward. Retinoblastoma can be hereditary and is more likely to develop in children with a family history of the disease.
With early diagnosis, retinoblastoma treatment is remarkably effective. More than 90% of children survive and many eyes are saved with a combination of medications, radiation therapy, and heat, freezing, or laser treatments. In severe cases, the affected eye is removed.
If a child has had retinoblastoma there is an increased chance for a second cancer to develop. Children with retinoblastoma should have regular examinations by an ophthalmologist and a pediatric oncologist.
Retinopathy of Prematurity (ROP)
Retinopathy of Prematurity (ROP) damages premature babies’ retinas, the layer of light-sensitive cells lining the back of the eye. ROP usually occurs in both eyes, though one may be more severely affected.
The last 12 weeks of a full-term pregnancy are an especially active time for the growth of the eye. When a baby is born prematurely, blood vessels are not ready to supply blood to the retina. At birth, abnormal new blood vessels form and cause scarring or detachment of the retina. The condition is especially common in very small babies. It is more likely to occur at one or two pounds than at three pounds.
Despite improved medical care, the disease is becoming more common because smaller and sicker infants are surviving. Supplemental oxygen given to premature babies may be part of the cause of ROP, but not the only factor, as once thought.
In severe cases, the retina may be extremely scarred and detached. Many cases get better without treatment and only a small number of children go blind. Freezing (cryotherapy) or laser treatments can prevent progression of the disease.
Children with ROP are more likely to develop nearsightedness and amblyopia (lazy eye). Glasses, patching, and eye muscle surgery can help these associated problems. Follow-up exams of severely affected children should continue periodically.