Retinoschisis


OVERVIEW

Retinoschisis is a disease of the nerve tissue in the eye. It affects the retinal cells in the macula (the central fixation point of vision at the back of the eye). Retinoschisis is technically a form of macular degeneration. However there are different types of macular degeneration and many people diagnosed with macular degeneration do not have retinoschisis.

Retinoschisis
Retinoschisis is a genetic eye disease that affects the vision of men who inherit the disease from their mothers. This condition frequently starts during childhood and is officially called Juvenile X-linked Retinoschisis. Affected men inherit this trait from their mothers who carry the condition but retain normal vision.

Juvenile X-linked Retinoschisis
Juvenile X-linked Retinoschisis is a genetic disease of the retina and affects primarily boys and young men. It is estimated that retinoschisis affects one in 5,000 to 25,000 individuals, primarily young males. Affected males are usually identified in grade school, but occasionally are identified as young infants. Affected boys and men should have periodic eye examinations.
 

Senile retinoschisis
Senile retinoschisis is the splitting of the retina as a result of aging. It can affect men and women. This is not a genetic condition.

Very few affected individuals go blind from retinoschisis. However, some men with retinoschisis have very limited reading vision and are "legally blind" because their visual acuity is less than 20/200 in both eyes. (Acuity of 20/60 or better is usually required for a drivers license.)
Retinoschisis (RS) affects two primary aspects of vision

First, central vision can be impaired. Visual acuity can range from 20/30 to less than 20/200. The acuity loss in RS is caused by the formation of tiny cysts in the retina. These cysts often form a "spoke-wheel" pattern which is frequently very subtle and is usually detected only by a trained clinician. Since the nerve tissue is damaged by these cysts, the visual acuity cannot be improved with glasses. Second, peripheral vision can be lost due to the splitting of the inner layer of nerve cells from the outer layer of cells. "Schisis" is derived from a Latin word meaning "splitting" and gives the name to this disease.

Retinal detachments can occur if the anchoring of the outer layer of the retina to the eye wall is impaired. Since RS patients are more susceptible to retinal detachments, regular examinations with an ophthalmologist are important. When detected early, retinal detachments can be treated surgically. However, splitting or schisis of the retina cannot be corrected by medication or surgery. Retinoschisis can be confused with other eye diseases, such as a "lazy eye". If someone in your family has retinoschisis and you are diagnosed with a lazy eye you should have an thorough exam by an ophthalmologist.





SYMPTOMS

  Decreased vision
  Loss of peripheral vision

The symptoms described above may not necessarily mean that you have retinoschisis. However, if you experience one or more of these symptoms, contact your eye doctor for a complete exam.





DIAGNOSIS & TESTING

The electroretinogram (ERG) is an important test used in assessing the function of the nerve tissue (retina) in the back of the eye. The eye is stimulated with light after either dark or light adaptation. Contact lenses, embedded with an electrode, are worn by the patient. The reaction of the eye is recorded and evaluated. This test expresses photoreceptor activity and the overall response of the external layer of the retina, and is a very important tool in diagnosis.

ERGs are performed on adults and on children under 24 months of age without requiring general anesthesia. ERGs performed on children between the ages of 2 and 5 can be difficult. Therefore we encourage the testing be done before age 2 or after age 5. In general, after age 5, nearly all children can have an ERG without any difficulties.

All children, even without retinoschisis, should have their vision checked yearly and glasses prescribed as necessary. Children who show schisis of the peripheral retina need more frequent examinations. These should be conducted by a subspecialty trained retina surgeon in case a detachment occurs that requires surgery. Follow-up intervals are best determined by the doctor who is following your individual child.





TREATMENT

Currently, there are no medical or surgical treatments available for retinoschisis. If you are nearsighted or farsighted, glasses may improve the overall quality of vision. However, because retinoschisis is a disease of the nerve tissue, glasses will not "repair" this nerve tissue damage.
Vitamin A will probably not help in retinoschisis.

Vitamin A may have benefits for other genetic retinal diseases, particularly in cases of retinitis pigmentosa where the retinal nerve cells are slowly dying. The retinoschisis disease is quite different from retinitis pigmentosa, since the retinal cells in retinoschisis are mechanically disrupted but are not thought to be dying.