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RETINAL DETACHMENT |  |
The retina is the neurosensory tissue that lines the back inside wall of the eye, just like wall paper on a sheetrock wall. Just like the film in a camera, the retina transfers the light coming into our eye into vision. The center of the retina is called the macula and is the only part capable of fine detailed vision, i.e. reading vision, recognizing faces, etc. The remainder of the retina, the peripheral retina, is for side vision. The retina outside the center of the macula, which makes up more than 95% of the retina, is not capable of the fine detailed vision.
When the retina detaches, it separates from the back wall of the eye and is removed from its blood supply and source of nutrition. The retina will degenerate and lose its ability to function if it remains detached. Central vision will be lost if the macula remains detached. The causes of retinal detachment can be divided into three main categories:
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Rhegmatogenous retinal detachment: This detachment is due to a retinal break or tear which allows the liquid vitreous (the fluid that fills the center of the eye ball) to pass through the break and lift off the retina. This is the most common type of detachment.
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Exudative retinal detachment: This detachment is due to leakage of fluid from under the retina. The fluid is called exudate. Tumors and inflammatory disorders can create exudative detachments.
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Traction retinal detachments: This type of detachment is due to pulling on the retina usually from fibro-vascular tissue within the vitreous cavity. Proliferative diabetic retinopathy is the most common cause of traction retinal detachments.
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What Causes Retinal Detachments? | |
An injury to the eye or face can cause a detached retina, as can very high levels of nearsightedness. Extremely nearsighted people have longer eyeballs with thinner retinas that are more prone to detaching.
Retinal detachment can occur as a result of LASIK, typically in the highly myopic, but this is a rare complication. In a study of more than 1,500 LASIK patients, just four suffered retinal detachment; their pre-LASIK prescriptions ranged from -8.00 D to -27.50 D.
Cataract surgery, tumors, eye disease and systemic diseases such as diabetes and sickle cell disease may also cause retinal detachments. New blood vessels growing under the retina — which can happen in diseases such as diabetic retinopathy may push the retina away from its support network as well. Sometimes fluid movement in the eye pulls the retina away.
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Treatment | |
Retinal tears will usually need to be treated with laser surgery or cryotherapy (freezing), to seal the retina to the back wall of the eye again. These treatments cause little or no discomfort and may be performed in your ophthalmologist's office. This treatment will usually prevent progression to a retinal detachment. Occasionally retinal tears are watched without treatment.
Retinal detachments may require surgery to return the retina to its proper position in the back of the eye. There are several ways to fix a detached retina. The decision of which type of surgery and anesthesia (local or general) to use depends upon the characteristics of the retinal detachment. In each of the following methods, your ophthalmologist will locate any retinal tears and use laser surgery or cryotherapy (freezing) around them to seal the tear.
Pneumatic retinopexy describes the injection of a gas bubble into the vitreous space inside the eye enabling the gas bubble to push the retinal tear back against the wall of the eye and close the tear. Laser or cryo-surgery is used to secure the retina to the eye wall around the retinal tear. Your ophthalmologist will ask you to maintain a certain head position for several days. The gas bubble will gradually disappear. Sometimes this procedure can be done in the ophthalmologist's office.
A scleral buckle or flexible band is placed around the equator of the eye to counterbalance any force pulling the retina out of place. Often the ophthalmologist will drain the fluid from under the detached retina allowing the retina to return back to its normal position against the back wall of the eye. This procedure is performed in the operating room, usually on an outpatient basis.
Vitrectomy may be necessary to remove any vitreous gel which is pulling on the retina. This may also be necessary if the vitreous is to be replaced with a gas bubble. Your body's own fluids will gradually replace this gas bubble, but the vitreous gel does not return. Sometimes a vitrectomy may be combined with a scleral buckle.
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Vitrectomy | |
Vitrectomy is a microsurgical procedure in which specialized instruments and techniques are used to repair retinal disorders, many of which were previously considered inoperable. The initial step in this procedure is usually the removal of the vitreous gel through very small (1.4mm) incisions in the eye wall, hence the name "vitrectomy". The vitreous is removed with a miniature handheld cutting device and replaced with a special saline solution similar to the liquid being removed from the eye. A high intensity fiber optic light source is used to illuminate the inside of the eye while the surgeon works. The surgeon uses a specialized operating microscope and contact lenses, which allow a clear view of the vitreous cavity and retina at various magnifications. The procedure is performed in an operating room under local or (occasionally) general anesthesia. It can often be done as an ambulatory procedure.
Although vitrectomy procedures are sometimes performed through incisions made near the front of the eye, most vitreoretinal surgeons enter the globe through a part of the eye known as the pars plana. This is why the procedure is often referred to as a trans pars plana vitrectomy (TPPV).
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