What You Should Know About Retinal Tears and Detachment

Retinal detachment is a condition in which the vitreous gel that fills the eye contracts and fails to separate cleanly from the retina, the 150 micron thick lining of the back of the eye (about as thick as a Kleenex). Instead, the vitreous pulls and tears a hole in the retina, often but not always causing the affected person to see a flash of light with floaters. Subsequently, eye motions cause swirling currents of saline inside the eye to pass through the retinal break and separate the retina from the underlying nutritive layer called the choroid. Figure 1 shows the normal situation in the eye.

Figure 2 shows an eye that has suffered a retinal break and subsequent retinal detachment. Without treatment, a retinal detachment almost always leads to progressive loss of vision, and usually blindness in the affected eye.

Are Certain People at Higher Risk for Retinal Tears and Detachment?
Highly near-sighted people have higher rates of retinal breaks and retinal detachment. Patients who have had cataract surgery are more likely to develop retinal detachment. The common causative thread shared by both of these groups of patients is that they develop shrinkage and degeneration of the vitreous gel. Other groups at increased risk include patients with eye trauma and persons with a family history of retinal breaks or retinal detachment. There is a genetic predisposition to develop thin spots in the retina where the vitreous gel is more firmly attached. These areas are called patches of lattice degeneration, because they appear as criss-crossing white lines to the examining ophthalmologist. Figure 3 shows such a lesion.

How is a Retinal Detachment Repaired?
There are several ways to repair a retinal detachment. Sometimes a small detachment can simply be bounded by several rows of laser treatment, done in the office. Laser treatment acts like spot-welding, sealing off the seeing, attached retina from the non-seeing, detached retina. In more severe cases, a gas bubble may be injected into the vitreous cavity, and the patient asked to position in such a way that the fluid beneath the retina is pumped out. Once the fluid is gone, laser treatment can be applied around the responsible retinal break. After two to six weeks, the bubble of gas is reabsorbed, the eye fills with saline made by the body, and vision returns. This procedure is called a pneumatic retinopexy.

When there are multiple breaks and the vitreous is not cloudy, a procedure called scleral buckling may be recommended. A scleral buckle is a band of silicone rubber, which is sutured to the wall of the eye, indenting the wall under the retinal breaks, and thus closing them. Once they are closed, the eye has a pumping mechanism to expel the fluid collected under the retina. Figure 4 shows a scleral buckle in place.

Lastly, if there is significant blood or debris in the vitreous gel, a vitrectomy may be done. Vitrectomy involves the removal of the vitreous gel and the debris and the replacement with sterile saline. The body constantly makes its own saline, which replaces that instilled during surgery within 2-3 days. Figure 5 shows the instruments used to remove the vitreous gel in a vitrectomy.

Frequently, more than one type of repair will be combined. Sometimes a vitrectomy, scleral buckle, and gas bubble will be combined to repair the detachment.

Certain types of retinal detachment bear emphasis. Some patients have extremely large retinal breaks called giant retinal tears. By definition, a giant retinal tear extends more than one-quarter around the circumference of the eye. The retina in these cases often folds over on itself, and special techniques must be used to unfold it. Sometimes, a heavy, clear fluid called perfluoron is used to do this. Sometimes a clear silicone oil bubble is left in the eye to keep the retina unrolled and flat during healing. The perfluoron is removed at the end of the initial surgery. The silicone oil bubble may be removed in a separate operation after a few months.

The most challenging type of retinal detachment to repair is one with proliferative vitreoretinopathy, which simply means that scar tissue has grown on the front or back or both surfaces of the retina. Tedious stripping of these scar membranes is required to render the retina flexible again and able to flatten back into position. Presence of proliferative vitreoretinopathy lowers the odds for successful repair of the detachment with one operation. Sometimes 2, 3, or rarely 4 operations may be required, and the visual outcomes are usually modest at best.

Prognosis
Taking all comers, the rate of successful repair of retinal detachment with one operation is approximately 90%. Ten percent of patients may require two or more operations to reattach the retina. When you discuss your particular situation, your doctor will give you a more individualized idea of how you stand, and if your prognosis is better or worse than this global figure.

Most patients with retinal detachment end up more near-sighted after surgery because of the effect of the scleral buckle. Therefore, you should expect to change your eyeglasses or contact lenses roughly 6-8 weeks after surgery.

In more than 95% of cases, final vision is improved compared to that at the time of diagnosis, but it is a mistake to expect to be “good as new”. Frequently, the vision will be somewhat diminished compared to the time before you had a problem. Retinal detachment surgery is more draining to a patient than cataract surgery or LASIK surgery. You may feel listless for a week or so. Expect to be out of work or school for approximately one week. You may be asked to position yourself face down or on one side for several days. We use local anesthesia in over 95% of cases – we rarely use general anesthesia.

Late Effects of Retinal Detachment Surgery
If you have your natural lens, retinal detachment surgery often causes formation of a cataract earlier than it would normally occur if you had not had a retinal detachment. At the appropriate time, cataract surgery can remedy this. In perhaps 1-2% of cases after a retinal detachment repair, a thin membrane of scar tissue grows on the surface of the central retina. This so-called macular pucker can be surgically removed if it compromises vision. Often it does not progress to a point requiring surgery.