Tuesday, September 02, 2014

Retinal Detachment

Definition

Retinal Detachment is a separation of the retina (the inner nervous tunic of the eye) from the choroid (the middle, vascular tunic of the eye) in the back of the eye, usually resulting from a hole in the retina that allows the vitreous humor (fluid) to leak between the choroid and the retina.

Description

The retina is a thin, transparent tissue of light-sensitive nerve fibers and cells. It covers the inside wall of the eye the same as wallpaper covers the walls of a room.

Most retinal detachments are caused by the presence of one or more small tears or holes in the retina. Normal aging can sometimes cause the retina to thin and deteriorate, but more often shrinkage of the vitreous body, the clear gel-like substance which fills the center of the eye, is responsible for deterioration and retinal tears.

The vitreous is firmly attached to the retina in several places around the back wall of the eye. As the vitreous shrinks, it may pull a piece of the retina away with it, leaving a tear or hole in the retina.

Though some shrinkage of the vitreous body occurs naturally with aging and usually causes no damage to the retina, abnormal growth of the eye (sometimes a result of nearsightedness), inflammation or injury, may also cause the vitreous to shrink. In most cases, a significant change in the structure of the vitreous body occurs before the development of a retinal detachment.

Once a retinal tear is present, watery fluid from the vitreous space may pass through the hole and flow between the retina and the back wall of the eye. This separates the retina from the back of the eye and causes it to "detach." The part of the retina that is detached will not work properly and there will be a blindspot in vision.

Causes

Retinal detachment will affect about one out of 10,000 people each year in the U.S. It is a serious eye problem that may occur at any age, though usually it occurs in middle-aged or older individuals.

It is more likely to develop in people who are nearsighted, or whose relatives had retinal detachments. A hard, solid blow to the eye may also cause the retina to detach. Severe trauma to the eye, such as a contusion or a penetrating wound, may be the cause, but in the great majority of cases, retinal detachment is the result of internal changes in the vitreous chamber associated with aging, or less frequently, with inflammation of the interior of the eye.

It should be noted that there are some retinal detachments that are caused by other diseases, such as tumors, severe inflammations or complications of diabetes. These so-called secondary detachments do not have holes or tears in the retina, and treatment of the disease which caused the retinal detachment is the only treatment which may allow the retina to return to its normal position.

Symptoms

In most cases, retinal detachment develops slowly. The first symptom is often the sudden appearance of a large number of spots floating loosely in the eye. The person may not seek help, because the number of spots tends to decrease during the days and weeks before detachment. The person may also notice a curious sensation of flashing lights as the eye is moved.

Because the retina does not contain sensory nerves that relay sensations of pain, the condition is painless.

Detachment usually begins at the thin peripheral edge of the retina and extends gradually beneath the thicker, more central areas. The person perceives a shadow that begins laterally and grows in size, slowly encroaching on central vision. As long as the center of the retina is unaffected, the vision when the person is looking straight ahead, is normal; but when the center becomes affected, the eyesight is distorted, wavy and indistinct. If the process of detachment is not halted, total blindness of the eye ultimately results. The condition does not spontaneously resolve itself.

Treatment

All cases of retinal detachment should be referred to an ophthalmologist as soon as possible.

If the retina is torn and retinal detachment has not yet occurred, a detachment may be prevented by prompt treatment. Treatment is aimed at closing retinal tears (so as to facilitate reattachment of the retina). Once the retina becomes detached, it must be repaired surgically.

Certain types of uncomplicated retinal detachment are now being treated by the technique of pneumatic retinopexy. The retina is reattached by injection of expansile gas into the vitreous cavity (a procedure that can be performed under local anesthesia as an office procedure) followed by careful positioning of the head. Once the retina is reattached, the retinal tear can be sealed by laser photocoagulation or cryotherapy. Occasionally, removal of vitreous and internal tamponade of the retina with air, expansile gases or even silicone oil, is necessary.

About 80 percent of all uncomplicated cases can be cured with one operation; an additional 15 percent will need repeated operations and the remainder will never reattach. The prognosis is worse if the macula is detached or if the detachment is of long duration.

Without treatment, retinal detachment often becomes total within six (6) months. Unfortunately, due to continual shrinkage of the vitreous and the development of fibrous growths on the retina, not all retinas can be reattached. If the retina cannot be reattached, then the eye will continue to lose sight and ultimately become blind.

Questions

What tests need to be done to diagnose the condition?

How much of the retina is torn or detached?

How serious is it?

Can the condition be cured?

What treatment do you recommend? How effective is the treatment?

What is the procedure of the surgery?

What are the risks of the surgery?

What can be expected from the surgery?