What is retinal detachment?
The retina is the light-sensitive layer of tissue that lines the inside of the eye and sends visual messages through the optic nerve to the brain. When the retina detaches, it is lifted or pulled from its normal position. If not promptly treated, retinal detachment can cause permanent vision loss.
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Posterior Vitreous Detachment
In some cases there may be small areas of the retina that are torn. These areas, called retinal tears or retinal breaks, commonly occur when there is traction on the retina by the vitreous gel inside the eye. In a child’s eye, the vitreous has an egg-white consistency and is firmly attached to certain areas of the retina. Over time, the vitreous gradually becomes thinner, more liquid and separates from the retina. This is known as a posterior vitreous detachment (PVD).
PVDs are typically harmless and cause floaters in the eye; but in some cases, the traction on the retina may create a tear. Retinal tears frequently lead to detachments as fluid seeps underneath the retina, causing it to separate and detach.
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What are the symptoms of retinal detachment?
Symptoms include a sudden or gradual increase in either the number of floaters, which are little "cobwebs" or specks that float about in your field of vision, and/or light flashes in the eye. Another symptom is the appearance of a curtain over the field of vision. A retinal detachment is a medical emergency. Anyone experiencing the symptoms of a retinal detachment should see an eye care professional immediately.
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What are the different types of retinal detachment?
There are three different types of retinal detachment:
- Rhegmatogenous [reg-ma-TAH-jenous] -- A tear or break in the retina allows fluid to get under the retina and separate it from the retinal pigment epithelium (RPE), the pigmented cell layer that nourishes the retina. These types of retinal detachments are the most common.
- Tractional -- In this type of detachment, scar tissue on the retina's surface contracts and causes the retina to separate from the RPE. This type of detachment is less common.
- Exudative -- Frequently caused by retinal diseases, including inflammatory disorders and injury/trauma to the eye. In this type, fluid leaks into the area underneath the retina, but there are no tears or breaks in the retina.
Who is at risk for retinal detachment?
A retinal detachment can occur at any age, but it is more common in people over age 40. A retinal detachment is also more likely to occur in people who:
- Are extremely nearsighted
- Have had a retinal detachment in the other eye
- Have a family history of retinal detachment
- Have had cataract surgery
- Have other eye diseases or disorders, such as retinoschisis, uveitis, degenerative myopia, or lattice degeneration
- Have had an eye injury
Detection and Diagnosis
Retinal detachments are usually found because the patient calls the doctor’s office with a symptom mentioned above. It is critical that these problems are reported early, because early treatment can greatly improve the chance of restoring vision.
The doctor makes the diagnosis of a retinal detachment after thoroughly examining the retina with ophthalmoscopy. The retinal surgeon’s first concern is to determine whether the macula (the center of the retina) is attached. This is critical because the macula is responsible for the central vision. Whether or not the macula is attached determines the type of corrective surgery required and the patient’s chances of having functional vision after the operation.
Ultrasound imaging of the eye is also very useful for the doctor to see additional detail of the condition of the retina from several angles.
How is retinal detachment treated?
Small holes and tears are treated with laser surgery or a freeze treatment called cryopexy. These procedures are usually performed in the doctor's office. During laser surgery tiny burns are made around the hole to "weld" the retina back into place. Cryopexy freezes the area around the hole and helps reattach the retina.
Pneumatic Retinopexy
Retinal detachments are treated with surgery that may require the patient to stay in the hospital. Pneumatic retinopexy is one type of procedure to reattach the retina. After numbing the eye with a local anesthesia, the surgeon injects a small gas bubble into the vitreous cavity. The bubble presses against the retina, flattening it against the back wall of the eye. Since the gas rises, this treatment is most effective for detachments located in the upper portion of the eye. In order to manipulate the bubble into the ideal location, the surgeon may ask the patient to keep his or her head in a specific position. The gas bubble slowly absorbs over the next 2-6 weeks.
Scleral Buckling
In some cases a scleral buckle, a tiny synthetic band, is attached to the outside of the eyeball to gently push the wall of the eye against the detached retina. The scleral buckle is not visible and remains permanently attached to the eye. This technique of reattaching the retina may elongate the eye, causing nearsightedness.
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Pars Plana Vitrectomy
If necessary, a vitrectomy may also be performed. During a vitrectomy, the doctor makes a tiny incision in the sclera (white of the eye). Next, a small instrument is placed into the eye to remove the vitreous, a gel-like substance that fills the center of the eye and helps the eye maintain a round shape. Gas is often injected to into the eye to replace the vitreous and reattach the retina; the gas pushes the retina back against the wall of the eye. During the healing process, the eye makes fluid that gradually replaces the gas and fills the eye. With all of these procedures, either laser or cryopexy is used to "weld" the retina back in place.
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Outcomes
With modern therapy, over 90 percent of those with a retinal detachment can be successfully treated, although sometimes a second treatment is needed. However, the visual outcome is not always predictable. The final visual result may not be known for up to several months following surgery. Even under the best of circumstances, and even after multiple attempts at repair, treatment sometimes fails and vision may eventually be lost. Visual results are best if the retinal detachment is repaired before the macula (the center region of the retina responsible for fine, detailed vision) detaches. That is why it is important to contact an eye care professional immediately if you see a sudden or gradual increase in the number of floaters and/or light flashes, or a dark curtain over the field of vision.
