Encyclopedia - Retinal Detachment

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Encyclopedia - Retinal Detachment

What are the types of retinal detachment?
What are the warning signs?
How is retinal detachment treated?

Retinal detachment occurs when the light-sensitive inner surface of the back of the eye becomes separated from the outer layers (See Anatomy of the Eye). Quick treatment is needed when this happens to prevent loss of vision in the affected eye. The risk of retinal detachment is higher for persons who are highly myopic (nearsighted), who have thin retinas, and those who have had cataract surgery.

What are the types of retinal detachment?

There are three kinds of retinal detachment:

Most often, retinal detachment occurs when a tear or hole develops in the retina. Fluid from the vitreous gel seeps into the opening, causing the inner surface of the retina to become detached. This kind of retinal detachment, called rhegmatogenous or mechanical detachment, can occur in persons who have suffered injuries to the eye.
A less common form is traditional retinal detachment, in which there is fibrous tissue on the inner surface of the retina that contracts to pull the layers of the retina apart. Patients with diabetic retinopathy who have experienced a vitreous hemorrhage that produces scar tissue are vulnerable to this form of detachment. This can also occur after an eye injury or after surgery to repair the more common kind of detachment.
A third form is exudative retinal detachment, in which fluid oozes from the choroid, the layer of blood vessels between the retina and the sclera. This fluid then accumulates under the retina. An inflammation of the eye, uveitis or age-related macular degeneration can trigger this seepage.

What are the warning signs?

The warning symptoms of retinal detachment include the occurrence, gradual or sudden, of flashes in one eye, usually at the edge of the field of vision and especially noticeable in the dark, lasting only a few seconds. Another symptom that may accompany these lightning-like flashes is a gradual or sudden appearance of floaters in one eye, which are spots or specks that can resemble insects, rings or even hearts. The flashes occur when the light-sensitive cells of the retina are stimulated as the detachment begins, while the floaters result from the release of blood or pigment into the vitreous gel, the fluid that fills the eye. But sometimes the first symptom is the sudden occurrence of a dark drape, or curtain, that obscures part of the field of vision.

How is retinal detachment treated?

Quick action is needed to prevent detachment of the macula, the center of the retina, which causes loss of central vision. When the macula becomes detached, restoration of central vision may be impossible. If a drape or curtain has appeared, the position of the patient during treatment is important. If there is a descending drape, or lower detachment, the patient can remain upright, but if there is an upper detachment, the patient will be told to lie down to help prevent further detachment.

Retinal detachment is treated by specialized surgery. For mechanical detachment, the retinal surgeon will compress the sclera, which is the white of the eye, and use either a buckle or very small sponges to push the layers of the retina together again. Sometimes gas bubbles may be injected into the vitreous cavity to increase the push. Or, diathermy, which is heat treatment, may help reattach the retina. The patient may be told to stay in one position for several hours to facilitate the reattachment.

The tear or hole causing the detachment can be treated by bursts of laser light or cryotherapy, a freezing technique, to weld the retina together again. In some cases, retinal fluid that has accumulated beneath the detached segment of the retina will be drained surgically. Complex microsurgical methods have been developed in recent years for treatment of the various kinds of retinal detachment.