A tear or hole of the retina that leads to a peripheral retinal detachment causes the loss of side (peripheral) vision. Almost all of these patients will progress to a full retinal detachment and loss of all vision if the problem is not repaired. The dark shadow or curtain obscuring a portion of the vision, either from the side, above, or below, almost invariably will advance to the loss of all useful vision. Spontaneous reattachment of the retina is rare.
Early diagnosis and repair are urgent since visual improvement is much greater when the retina is repaired before the macula or central area is detached. The surgical repair of a retinal detachment is usually successful in reattaching the retina, although more than one procedure may be necessary. Once the retina is reattached, vision usually improves and then stabilizes. Successful reattachment does not always result in normal vision. The ability to read after successful surgery will depend on whether or not the macula (central part of the retina) was detached and the extent of time that it was detached.
Retinal holes or tears can be treated with laser therapy or cryotherapy (freezing) to prevent their progression to a full-scale detachment. Many factors determine which holes or tears need to be treated. These factors include the type and location of the defects, whether pulling on the retina (traction) or bleeding is involved, and the presence of any of the other risk factors discussed above. Three types of eye surgery are done for actual retinal detachment: scleral buckling, pneumatic retinopexy, and vitrectomy.
Scleral buckling
For many years, scleral buckling has been the standard treatment for detached retinas. The surgery is done in a hospital operating room with general or local anesthesia. Some patients stay in the hospital overnight (inpatient), while others 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, either with diathermy (an electric current which heats tissue), a cryoprobe (freezing), or a laser. This results in scar tissue later forming around the retinal tear to keep it permanently sealed, so that fluid no longer can pass through and behind the retina. A scleral buckle, which is made of silicone, plastic, or sponge, is then sewn to the outer wall of the eye (the sclera). The buckle is like a tight cinch or belt around the eye. This application compresses the eye 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. The buckle may be left in place permanently. It usually is not visible because the buckle is located half way around the back of the eye (posteriorly) and is covered by the conjunctiva (the clear outer covering of the eye), which is carefully sewn (sutured) over it. Compressing the eye with the buckle also reduces any possible later pulling (traction) by the vitreous on the retina.
A small slit in the sclera allows the surgeon to drain some of the fluid that has passed through and behind the retina. Removal of this fluid allows the retina to flatten in place against the back wall of the eye. A gas or air bubble may be placed into the vitreous cavity to help keep the hole or tear in proper position against the scleral buckle until the scarring has taken place. This procedure may require special positioning of the patient's head (such as looking down) so that the bubble can rise and better seal the break in the retina. The patient may have to walk, eat, and sleep with the head facing down for two to four weeks to achieve the desired result.
Pneumatic retinopexy
Pneumatic retinopexy is a newer method for repairing retinal detachments. It usually is performed on an outpatient basis under local anesthesia. Again, laser or cryotherapy is used to seal the hole or tear. The surgeon then 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 (sclera). The gas bubble initially expands and then disappears over two to six weeks. Proper positioning of the head in the postoperative time period is crucial for success. Although this treatment is inappropriate for the repair of many retinal detachments, it is simpler and much less costly than scleral buckling. Furthermore, if pneumatic retinopexy is unsuccessful, scleral buckling still can be performed.
Vitrectomy
Certain complicated or severe retinal detachments may require a more complicated operation called a vitrectomy. These detachments include those that are caused by the growth of abnormal blood vessels on the retina or in the vitreous, as occurs in advanced diabetes. Vitrectomy also is used with giant 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 performed in the hospital under general or local anesthesia. Small openings are made through the sclera to allow positioning of a fiberoptic light, a cutting source (specialized scissors), and a delicate forceps. The vitreous gel of the eye is removed and replaced with a gas to refill the eye and reposition the retina. The gas eventually is absorbed and is replaced by the eye's own natural fluid. A scleral buckle is usually also performed with the vitrectomy.
Discomfort, watering, redness, swelling, and itching of the affected eye are all common and may persist for some time after the operation. These symptoms are usually treated with eye drops. Blurred vision may last for many months, and new glasses may need to be prescribed, especially because the scleral buckle may have changed the shape of the eye. The scleral buckle also can cause double vision (diplopia) by affecting one of the muscles that controls the movements of the eye. Other complications can include elevated pressure in the eye (glaucoma), bleeding into the vitreous, within the retina or behind the retina, clouding of the lens of the eye (cataract), or drooping of the eyelid (ptosis). Additionally, infection can occur around the scleral buckle or even more widely in the eye (endophthalmitis). Occasionally, the buckle may need to be removed.
The surgical repair of retinal detachments is successful in about 80% of patients with a single procedure. With additional surgery, over 90% of retinas are reattached successfully. Several months may pass, however, before vision returns to its final level. The final outcome for vision depends on several factors. For example, if the macula was detached, central vision rarely will return to normal. Even if the macula was not detached, some vision may still be lost, although most will be regained. New holes, tears, or pulling may develop, leading to new retinal detachments. If a gas or air bubble was inserted in the eye during surgery, maintaining proper positioning of the head is also important in determining the final outcome. Close follow-up by an ophthalmologist, therefore, is required. Long-term studies have shown that even after preventive treatment of a retinal hole or tear, 5% to 9% of patients may develop new breaks in the retina, which could lead to a retinal detachment. Overall, however, repair of retinal detachments has made great strides in the past 20 years with the restoration of useful vision to many thousands of patients.
