Damage to the retina that can cause vision loss
Retinal detachment is a serious eye problem that affects one in every 10,000 people. Retinal detachment most often occurs after the age of 40 as a result of the natural aging process. Persons who are severely nearsighted, have a family history of retinal problems, or have undergone eye surgery are more likely to develop the disease. A significant eye injury may cause retinal detachment as well. Unless treated early, retinal detachment leads to sight loss and possibly blindness.
What Is the Retina?
The retina is a thin layer of light-sensitive tissue that lines the back of the eye. When light enters the eye, it is focused by the cornea and lens onto the retina. The retina then transforms the light images into electrical impulses, which are sent to the brain by the optic nerve.
The retina has two main parts, the macula and the peripheral retina. The macula is a small area in the center of the retina that is responsible for the fine, detailed vision used for reading and driving. The peripheral retina is the outer area of the retina that provides side or peripheral vision.
What Is Retinal Detachment?
Retinal detachment occurs when the retina becomes separated from the back wall of the eye. When the retina becomes detached, its blood supply is reduced and its ability to process light rays is impaired. If total detachment occurs, the retina becomes useless, as it can no longer transmit information to the brain, and the eye becomes blind.
What Causes Retinal Detachment?
As part of the normal aging process, the clear fluid that fills the inner cavity of the eye (vitreous) begins to shrink and pull away from the retina. Most of this shrinking causes no damage to the eye; however, sometimes the vitreous remains attached to the retina and the shrinking of the vitreous causes the retina to tear. These tears usually occur in the peripheral retina, where there is little effect on vision.
Left untreated, retinal tears can lead to retinal detachment. Once a retinal tear is present, fluid from the vitreous may seep through the tear into the space between the retina and the wall of the eye. The fluid causes the retina to separate from the back of the eye or detach. The part of the retina that becomes detached will not function properly, resulting in vision loss.
Retinal detachment can also be caused by tumors, inflammation and complications from diabetes. With these types of detachment, no holes or tears occur in the retina. Treatment of the disease causing the detachment is the only way to allow the retina to return to its normal position.
What Are the Symptoms of Retinal Tears and Detachment?
Retinal tears may develop without any noticeable symptoms. In other cases, the vitreous gel pulling away from the retina may cause the patient to see flashes of light. Floaters, which appear as black spots or lines in the field of vision, may result from bleeding of torn retinal vessels or the formation of small clumps of vitreous matter. Floaters and flashes do not always indicate a serious problem such as retinal tears, but a complete eye examination is necessary to determine their significance.
Once retinal detachment occurs, the patient may notice a wavy or watery quality in his vision. If detachment occurs in the peripheral retina, a curtain or shadow may appear across the field of vision. If the area of detachment is in the macula, central vision will be distorted and reduced. The patient will be unable to read or see in fine detail. Occasionally, detachment occurs suddenly and is accompanied by a total loss of vision.
How Are Retinal Tears and Detachment Diagnosed?
Since retinal tears and detachments cannot be seen from the outside of the eye, an ophthalmoscope is used to examine the interior of the eye. This instrument, which provides bright light and magnification, is useful in locating areas of retinal tearing. Other sophisticated eye instruments may be used to locate points of tearing and detachment.
How Are Retinal Tears and Detachment Treated?
Retinal tears require immediate treatment to prevent retinal detachment and sight loss. Treatment of retinal tears is designed to create a scar that welds the retina to the back of the eye to prevent further tearing. The scar seals the tear and blocks fluid from passing under the retina. Tears can be sealed with laser light or with a freezing probe (cryopexy). During laser treatment, heat from the laser is used to place small burns around the edge of the tear to seal the break. With cryopexy, extreme cold is applied to the surface of the eye at the point of the tear to form a scar. Both laser treatment and cryopexy are usually performed on an outpatient basis.
Once the retina becomes detached, it must be repaired surgically. During surgery, the liquid under the retina is removed and the retina is reattached to the back wall of the eye. Either the freezing or laser technique is used to produce a scar at the point of the tear or detachment. Scar tissue then forms to reattach the layers. A silicone band, held in place by nylon sutures, is usually wrapped around the outside of the eye to push the back wall of the eye against the retina to aid healing.
Over 90% of all retinal detachments can be surgically repaired, although occasionally more than one operation is required. Retinal surgery is done in a hospital under local or general anesthesia. Although the healing process takes 4-6 weeks, most patients are able to walk the day after surgery and are discharged from the hospital within a week. Successful reattachment of the retina will either restore vision or prevent further sight loss. The degree of vision present six months after surgery depends on several factors, including the time from detachment to treatment, the severity of the detachment, and the portion of the retina which was affected.
Prevention is the best medicine
Retinal tears and detachment are serious problems and require immediate treatment. Persons who are severely nearsighted or have a family history of retinal detachment should have regular eye examinations to detect any changes in the vitreous or retina. Persons who have suffered a serious eye injury should also be examined for retinal damage. With early diagnosis, retinal tears can be treated before retinal detachment and loss of vision occurs.
If you are experiencing the symptoms of a retinal tear or detachment or another vision problem, you should obtain a complete eye examination.