Retinoschisis is an uncommon eye disease characterized by the abnormal splitting of the retina's sensory layers, usually in the outer plexiform layer, with resulting loss of visual function. The retina, which consists of multiple layers of interconnected nerve and pigment cells, separates into separate layers resulting in a loss of vision in the corresponding visual field.
It is estimated that retinoschisis affects one in 5,000 to 25,000 individuals, primarily young males. "Schisis" is derived from the Greek word meaning "splitting," describing the splitting of the retinal layers from each other. If the retinoschisis involves the macula, then the high-resolution central area of vision used to view detail is lost, and this one form of macular degeneration. Treatment is often aimed at restricting any worsening of the separation so that it does not encroach on the macula.
Retinoschisis can be caused by an X-linked genetic defect, affecting the vision of men who inherit the disease from their unaffected carrier mothers. The genetic form of this disease usually starts during childhood and is called Juvenile X-linked Retinoschisis. Affected males are usually identified in grade school, but occasionally are identified as young infants. Senile retinoschisis, on the other hand, is the splitting of the retina as a result of aging. It can affect both men and women and is not a genetic condition.
Very few affected individuals go completely blind from retinoschisis, but some sufferers have very limited reading vision and are "legally blind". Visual acuity can be reduced to less than 20/200 in both eyes.
Retinoschisis causes acuity loss in the center of the visual field through the formation of tiny cysts in the retina, often forming a "spoke-wheel" pattern that can be very subtle. The cysts are usually only detectable by a trained clinician. Vision cannot be improved by glasses, as the nerve tissue itself is damaged by these cysts. Furthermore, peripheral vision can be lost due to the splitting of the inner layer of nerve cells from the outer layer of cells.
If the anchoring of the outer layer of the retina to the eye wall is impaired, retinal detachments can occur. Retinal detachments can be treated surgically when detected early, but the root cause - the splitting of the retina - cannot be corrected by current medications or surgeries. Since retinoschisis can be confused with other eye diseases such as lazy eye, it is important that a thorough exam be done by an ophthalmologist to ensure that retinal detachment is not overlooked.
- Cassin, B. and Solomon, S. Dictionary of Eye Terminology. Gainsville, Florida: Triad Publishing Company, 1990.