July 16, 2012 RETINOSCHISIS (SPLITTING OF THE RETINA)
Retinoschisis is an eye disease characterized by abnormal splitting of the neurosensitive layers of the retina, usually in the outer plexiform layer, resulting in loss of vision or of the corresponding visual field in some rare formats. More common forms are usually asymptomatic.
Types:
Degenerative retinoschisis
This type of retinoschisis is very common, with prevalence of up to 7 percent in normal people. The cause of it is unknown. Improper observer will easily confuse it with the retinal detachment, but in severe cases it can be difficult for experts too to differ these two conditions. Such a distinction is necessary because the retinal detachment almost always require treatment, while retinoschisis itself does not require treatment, and only sometimes causes a loss of vision. Unfortunately, sometimes cases of retinoschisis without complications can be seen that were treated by laser retinopexia or criopexia in order to prevent the progression towards the macula. Such treatments are not only ineffective, but also unnecessarily expose patients to risk of complications. There is no practical, clinical use of the distinction between typical and reticular retinoschisis. Degenerative retinoschisis is not a genetically determined condition.
Hereditary retinoschisis
This much less common form of retinoschisis affects one person of 5000-25000 people, primarily young men. If retinoschisis affects macula (yellow spot), it causes a lost of a central, highly sensitive area of vision for the details, so it is a form of macular disease.
Retinoschisis can be caused by X-linked genetic defect, affecting vision in men. A genetic defect man inherits from his mother who is a carrier of the defect, but did not show any symptoms. Genetic form of the disease usually begins during childhood and it is called the X-linked juvenile retinoschisis (XLRS) or congenital retinoschisis. Sick men are commonly detected in primary school or already as small children.
Only rarely suffered ones end up totally blind, while some patients have very reduced visual acuity. Visual acuity can be reduced to less than 10% in both eyes. People suffering from XLRS have an increased risk of separation of the retina and intraocular hemorrhage. Retinoschisis causes loss of visual acuity in the middle of the field of vision through a small cyst in the retina, often forming a pattern like spokes on the wheel that can be very subtle. Cysts are most commonly noticed by trained clinicians. Vision cannot be improved with glasses because these cysts have fine nerve tissue of the retina damaged.
Traction retinoschisis
It can occur in conditions caused by retinal traction especially those of the macula. This can happen in: vitreomacular traction syndrome, proliferative diabetic retinopathy with vitreoretinal traction, atypical cases of suspended macular rupture
Exudative retinoschisis
Retinoschisis that includes the central part of the retina secondarily, as a result of optic disc pits, was wrongly considered as a severe separation of the retina until Lincoff properly described it as retinoschisis. It can cause significant loss of vision. After the diagnosis, the state of the eye should be monitored for some time, because a spontaneous recovery is also possible. If a spontaneous recovery does not occur, nor does the vision improve, it is useful to do a laser treatment of the retina by the temporal edge of the optic disc, and sometimes vitrectomy with gas injection in the space of vitreous can also work. Another option is to keep the head in down position for several weeks after surgery.