Introduction
Retinoschisis is the term used to describe a split in the sensory retina. In this condition a new cleavage plane develops within that part of the retina derived from the inner layer of the optic cup; whereas in the retinal detachment, fluid accumulates between those parts of the retina derived from the inner and outer layers of the optic cup, between the retinal receptors (rods and cones) and the pigment epithelium. Retinoschisis can occur at any level of the sensory retina, but most commonly the cleavage takes place at the outer plexiform layer, with the accumulation of a mucopolysaccharide-rich viscous fluid within the schisis cavity. As the schisis progresses, the neural elements of the retina are at first stretched and finally lysed producing absolute visual loss in the affected areas. Clinically an absolute visual field defect corresponds to the area of retinoschisis.The diagnosis of retinoschisis is best made