Retinal Detachment

Retinal detachment is a disorder of the eye in which the retina gets detached from its fundamental layer of support tissue.

The retina is a thin layer of light-sensitive tissue lining at the back wall of the eye. The optical system of the eye focuses light on the retina just as the light is focused on the film of a camera. Now the retina translates that focused image into neural impulses and sends visual messages via optic nerve to the brain. The detachment of retina is a situation when retina is lifted or dislocated from its normal position. If not immediately treated, retinal detachment can lead to permanent loss of vision.

In some cases small areas of the retina can tear. These areas are termed as retinal tears or retinal breaks and can lead to retinal detachment.

Different types of retinal detachment:

Rhegmatogenous [reg-ma-TAH-jenous]

A tear or break in the retina allows fluid to enter the retina and disconnect it from the Retinal Pigment Epithelium (RPE), the pigmented cell layer that nourishes the retina. These types of retinal detachments are known to be the most common.

Tractional
In this type of detachment, scar tissue situated on the surface of the retina contracts and causes the retina to split from the RPE. But this type of detachment is not very common.

Exudative
This frequently leads to retinal diseases, such as inflammatory disorders and even injury or trauma to the eye. In this case, fluid leaks into the area beneath the retina, although there are no tears or breaks in the retina.

Causes and Risk Factors

A retinal detachment is also common 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 including retinoschisis, uveitis, degenerative myopia, or lattice degeneration
Have had an eye injury

Remember that there are some retinal detachments caused by other diseases like tumors, severe inflammations or complications of diabetes. These so-called secondary detachments are not detected to have holes or tears in the retina, and treatment of the disease which leads to the retinal detachment, is the only treatment which may allow the retina to go back to its normal location.

Who is at risk for retinal detachment?
A retinal detachment can happen at any age, but it is more frequent in people over age 40. It is interesting to note that it affects men rather than women and Whites in comparison to African Americans.

Symptoms

In most cases, retinal detachment develops gradually. The first symptom is often the sudden emergence of a large number of spots floating loosely in the eye. The person may not need help as the number of spots tends to decrease during the days and weeks before he experiences detachment. The person may also detect a curious feeling of flashing lights as the eye is moved.The retina does not contain sensory nerves that can transmit the sensations of pain. So, the condition is rather painless.

Detachment usually shows its sign first at the thin peripheral edge of the retina and extends slowly beneath the thicker, more central areas. The person sees a shadow that begins laterally and grows in size by time, slowly encroaching on central vision. As long as the center of the retina remains unaffected, the vision when the person is looking straight ahead is normal; but once the center gets affected, the eyesight is distorted, wavy and hazy. If the process of detachment is not controlled, it may cause total blindness of the eye. The condition has not the ability to spontaneously resolve itself. A retinal detachment is a medical emergency therefore anyone experiencing the symptoms of a retinal detachment should see an eye care professional immediately.

Treatment of Retinal Detachment

Small holes and tears can be treated with laser surgery or a freeze treatment known as Cryopexy. These procedures are generally followed in the doctor\’s chamber. During laser surgery tiny burns are created around the hole in order to \”weld\” the retina back into its actual position. During Cryopexy the area around the hole is freezed that helps reattach the retina.

3 types of eye surgery are performed for actual retinal detachment:

Scleral buckling
Pneumatic retinopexy
Vitrectomy

Scleral buckling

For many years, scleral buckling has been considered the standard treatment for detached retinas. The surgery is performed in a hospital operating room with general or local anesthesia. Some patients needs to stay in the hospital overnight (inpatient), while others can go home the same day (outpatient). The surgeon identifies the holes or tears either through the operating microscope or a focusing headlight (indirect ophthalmoscope). The hole or tear is then sealed. It is done either with diathermy (an electric current which heats tissue), a cryoprobe (freezing), or a laser. A scleral buckle, made of silicone, plastic, or sponge, is then sewn to the outer wall of the eye, known as the sclera. The buckle resembles a tight cinch or belt around the eye. This application makes the eye compressed so that the hole or tear in the retina is pushed against the outer scleral wall of the eye, which has been indented by the buckle.

A small incision in the sclera allows the surgeon to draw off some of the fluid that has passed through and behind the retina. As the fluid is removed, now the retina can flatten in place against the back wall of the eye. A gas or air bubble may be positioned into the vitreous cavity of the eye in order to retain the hole or tear in appropriate position against the scleral buckle until the scarring has occurred. In this procedure special positioning of the patient\’s head (such as looking down) is necessary as it enables the bubble to rise and better seal the break in the retina. The patient may have to walk, eat, and sleep with the head facing down for 2 to 4 weeks to get the good result.

Pneumatic retinopexy is a newer method for repairing retinal detachments and it is usually carried out on an outpatient basis under local anesthesia. Laser or Cryotherapy is performed to repair the hole or tear. The surgeon, in this process, injects a gas bubble directly inside the vitreous cavity of the eye to push the detached retina against the back outer wall of the eye called sclera. These gas bubbles primarily expand and then disappear over 2 to 6 weeks. Proper positioning of the head in the postoperative time period ensures success. Although this treatment is unsuitable for the repair of many retinal detachments, it is easier and much less expensive than scleral buckling. In addition, if pneumatic retinopexy proves unsuccessful, scleral buckling still can be performed.

Vitrectomy
Certain complicated or severe retinal detachments may demand a more complex operation called a vitrectomy. These kinds of detachments occur due to the development of abnormal blood vessels on the retina or in the vitreous, as found in advanced diabetes. Vasectomy also is used to treat serious retinal tears, vitreous hemorrhage (blood in the vitreous cavity that obscures the surgeon\’s view of the retina), extensive tractional retinal detachments (pulling from scar tissue), membranes (extra tissue) on the retina, or severe infections in the eye (endophthalmitis). Vitrectomy surgery is done in the hospital under general or local anesthesia. Little openings are made in this method through the sclera to allow positioning of a fiberoptic light, a cutting source (specialized scissors), and a delicate forceps. The surgeon, in this method, removes vitreous gel of the eye and replaces it with a gas to refill the eye and reposition the retina. This gas is ultimately absorbed and is replaced by the eye\’s own natural fluid. A scleral buckle is usually also performed with the vitrectomy.

What are the complications of surgery for a retinal detachment?
Discomfort, watering, redness, swelling, and itching of the affected eye are all common side effects of surgery after retinal detachment, and may stay for some time after the operation. The doctor may prescribe eye drops to treat these symptoms. Blurred vision may remain for a few months, and new glasses may require to be prescribed. This is especially because the scleral buckle may have altered the shape of the eye. The scleral buckle also can give rise to double vision (diplopia) which may cause due to an adverse effect on one of the muscles controlling the movements of the eye. Other complications are elevated pressure in the eye (also known as glaucoma), bleeding into the vitreous, within the retina or behind the retina, clouding of the lens of the eye that is, cataract, or drooping of the eyelid (ptosis). Furthermore, infection can take place around the scleral buckle or even more widely in the eye. This is clinically termed as endophthalmitis. Often, the buckle may need to be removed.

Success Rate

The success report of the surgical repair of retinal detachments is 80% of patients with a single procedure while with additional surgery; over 90% of retinas are reattached effectively. It may take several months, before vision returns to its final level. Long-term studies have revealed that even after preventive treatment of a retinal hole or tear, 5% to 9% of patients may experience new breaks in the retina, resulting in a retinal detachment. On the whole, however, repair of retinal detachments has made great strides in the past 20 years with the restitution of useful vision to numerous patients.