The retina is a thin layer of light-sensitive cells, covering three-quarters of the eyeballs. Beneath the retina is a layer of blood vessels – a nerve that supplies the retina with nutrients and oxygen.
Retinal detachment is the separation of the retina from the choroid. In most cases, separation causes an opening in the retina that occurs due to retinal degeneration or because the vitreous body separates from the retina and tears it. The opening is usually created close to the front edge of the retina. Liquid from the vitreous body flows out through the opening and begins to separate the retina from the choroid.
If the condition is not treated, the process continues, so that the retina detaches even more. In the end, it only holds the cervical body (extension of choroid) at the front of the eye, and at the back of the eye only the edge of the optic nerve disc (the end of visual nerve).
This condition can affect both eyes, but almost never at the same time.
The only symptoms are visual disturbances on the affected eye. However, since the other eye is almost always normal, you may not notice initial symptoms at first. The first signs of this disorder may be flashes that often occur somewhat before the hole appears in the retina. When the opening has already begun, the patient sees floating, black, often spotted shapes. With the development of retial detachment, a part of the external visual field is lost in the diseased eye. It often looks like a black curtain over the eye. If the condition is not treated, the entire field of vision is lost.
Retinal detachment is rare. In Britain, one in 10 000 people suffer from this disease. It usually occurs after middle ages and affects both men and women equally. People who are especially at risk are people with myopia (short-sightedness); people with eye injuries or those whose lens are removed from the eye due to cataract are also prone to retinal detachment.
If the disorder is neglected, there is a danger of permanent blindness in the diseased eye. Sometimes, the retinal detachment in one eye occurs after detachment in the other; during the therapy, measures may be taken to prevent this.
What to do?
If you feel any of the symptoms described, contact your doctor immediately. The doctor will detect retinal detachment by looking at the eye with an instrument called the ophthalmoscope.
If an opening is detected on the retina before the retinal detachment begins, the opening is permanently closed by freezing or by laser with local anesthesia. If the retinal detachment has already begun, surgery is performed with general anesthesia. The outer layers of the eyeball in the area of the opening on the retina are pressed against the retina and the opening is permanently closed by freezing. The retina and the choroid can then absorb the liquid that is formed between them – or, if this does not happen, the fluid runs out and the retina returns to its normal position.
If the surgical procedure is performed before the condition has affected the macula lutea (central part of the retina), the sight usually returns after the operation. If the retinal detachment spreads and direct vision is impaired, the vision will be somewhat persistent blurred, although usually the entire field of vision returns to normal. In 10% of the complete retinal detachment, the retina does not drop onto choroid after surgery, and that means blindness. After surgery, retinal detachment reappears only in a small number of cases.
After retinal detachment on one eye, there is a significant risk that it will develop on the other eye; vulnerable sites on the retina can be detected and treated, often at the same time as the retinal detachment of the other eye.