What Is Retinoschisis?
Retinoschisis occurs when a separation (schisis) develops between the two major layers of the retina, creating a blister-like elevation that can be confused with a true retinal detachment. Retinoschisis usually occurs in the far periphery of the retina and resembles a clear dome that is sometimes difficult to photograph with a retinal camera. Retinoschisis is often, but not exclusively, a condition of aging.
What Causes Retinoschisis?
Retinoschisis is observed in about one percent of the population and frequently occurs in both eyes. Aging can cause cysts within the retina and these gradually become a complex of interlacing tunnels. If enough cystic spaces coalesce, the retina will form a retinoschisis, splitting into an inner and outer layer cavity. The retinal layers closest to the eye’s interior comprise the inner layer, while the deeper layers of the retina represent the outer layer of the retinoschisis cavity. The outer layer of the retina stays adherent to the back wall of the eye while fluid balloons up the inner layer. Over time, the “schisis cavity” may develop holes in one or both layers.
What are the Symptoms?
Retinoschisis is asymptomatic except in those who develop either very extensive schisis cavities or retinal detachment.
How Serious is Retinoschisis?
Retinoschisis is typically a benign condition that causes no symptoms. In all types of acquired retinoschisis, either the inner layer or the outer layer, or both layers, may develop holes. Should holes develop in the inner layer of the retinoschisis, then liquid vitreous may flow into the fluid cavity. This does not change the prognosis. If there are both inner and outer layer holes, then liquid vitreous can work its way under both retinal layers and cause a retinal detachment. Fortunately double layer holes occur very rarely. The risk of progression to retinal detachment in retinoschisis with double layer holes is 0.25 to 1.4 percent. The risk of detachment without double layer holes is nearly zero.
What can be Done if my Retinoschisis Develops into a Retinal Detachment?
In the rare event that a retinoschisis develops double layer holes and becomes a retinal detachment, surgery can be done to try to place the retina back in its correct anatomic position.
The left portion of this photo shows a retinoschisis cavity. The edge of the “blister” is marked by the black arrows.
In this photo, the retinoschisis cavity is seen in the upper right portion of the picture. The margin between the split and normal retina is marked by the black arrows.
Holes can develop in either the inner layer or the outer layer of a retinoschisis cavity. Holes in either the inner layer alone or the outer layer alone do not change the overall very good prognosis.