Degenerative Retinoschisis

Degenerative Retinoschisis

Definition

A frequently bilateral split in an inner and outer layer of the retina. The split is usually at the level of the outer plexiform layer (Fig. 12.25).

Epidemiology: 

About 25% of all people have retinoschisis. The tendencyincreases with age.

Pathogenesis: 

Idiopathic retinal splitting occurs, usually in the outer plexi-form layer.

Symptoms: 

Retinoschisis isprimarily asymptomatic. The patient will usuallynotice a reduction of visual acuity and see shadows only when the retinal split is severe and extends to the posterior pole.

Diagnostic considerations: 

Ophthalmoscopic examination will revealbullous separation of the split inner layer of the retina. The inner surface has the appearance of hammered metal. Rarely breaks will occur in the inner and outer retinal layers.

Differential diagnosis: 

Rhegmatogenous retinal detachmentshould be ex-cluded. Ophthalmoscopy will reveal a continuous break in the retina in a reti-nal detachment, and the retina will not appear as transparent as in retino-schisis. However, retinal breaks can also occur in retinoschisis. In the inner layer of the retina, these breaks will be very small and hardly discernible. In the outer layer, they will be very large. Complete rhegmatogenous retinal detachment can occur in retinoschisis only where there is a break in both layers.

Treatment: 

Usually no treatment is required. The rare cases in which retinaldetachment occurs are treated surgically using the standard procedures for retinal detachment.

Degenerative retinoschisis differs from retinal detachment in that it usually requires no treatment.

Clinical course and prognosis: 

The prognosis for degenerative retinoschisisis very good. Progressive retinal splitting or retinal detachment with a sub-sequent reduction in visual acuity is rare.