Photocoagulation Therapy Health Article

Preparation

Treatment of RD follows as soon as possible after the diagnosis; however, an immediate procedure is not usually necessary since the time frame for treatment of a detached retina is several hours rather than only a few minutes.

If the patient has suffered a traumatic injury to the eye, the eye may be covered with a protective shield prior to treatment.

Preparation for photocoagulation therapy consists of eye drops that dilate the pupil of the eye and numb the eye itself. The laser treatment is painless, although some patients require additional anesthetic for sensitivity to the laser light.

Aftercare

Patients who have had photocoagulation therapy for retinal detachment are asked to have a friend or family member drive them home. The reason for this precaution is that the eye medication used to dilate the pupil of the patient's eye before the procedure takes several hours to wear off. During this period, the eye is unusually sensitive to light. The patient can go to work the next day with no restrictions on activity.

Risks

The most common risks of laser photocoagulation therapy are mild discomfort at the beginning of the procedure and the possibility that a second laser treatment will be needed to reattach the retina securely.

Normal results

Over 90% of retinal detachments can be repaired with prompt treatment, although sometimes a second procedure is needed. About 40% of patients treated for retinal detachment will have good vision within six months of surgery. The results are less favorable if the retina has been detached for a long time or if there is a large growth of fibrous tissue that has caused a traction detachment. These patients, however, will still have some degree of reading or traveling vision after the retina has been reattached. In a very small minority of patients, the surgeon cannot reattach the retina because of extensive growths of fibrous scar tissue on it.

Morbidity and mortality rates

The mortality rate for laser photocoagulation treatment of retinal detachment is extremely low; morbidity depends to a large extent on the cause of the RD. A study done in 2001 reported that laser therapy for rhegmatogenous RDs is as effective as pneumatic retinopexy or scleral buckling, but has the advantage of fewer complications after the procedure. In the treatment of ROP, laser photocoagulation has been found to be more effective than cryopexy in reducing the infant's risk of nearsightedness in later life.

Alternatives

Alternatives to laser photocoagulation as a treatment for RD depend on the location and size of the retinal detachment. Photocoagulation treatment works best on small tears in the retina. One alternative for the treatment of small areas of detachment is cryopexy, which is performed as an outpatient procedure under local anesthesia. In cryopexy, the ophthalmologist uses nitrous oxide to freeze the tissue underneath the retinal tear. This procedure leads to the formation of scar tissue that seals the edges of the tear in place.

Pneumatic retinopexy is a procedure that can be used if the RD is located in the upper part of the eye. After numbing the patient's eye with a local anesthetic, the ophthalmologist injects a small bubble of gas into the vitreous body. The gas bubble rises and presses the torn part of the retina back against the underlying choroid. The bubble is slowly absorbed over the next two weeks. The ophthalmologist then uses either photocoagulation or cryopexy to complete the reattachment of the retina.

If the RD is large, the doctor may decide to perform a scleral buckle treatment or a vitrectomy. These procedures are more invasive than laser photocoagulation or cryopexy; however, they are still usually done as outpatient procedures. In a scleral buckle procedure, the doctor attaches a tiny silicon band to the sclera. The buckle, which remains in the eye permanently, puts pressure on the retina to hold it in place.

In a vitrectomy, the ophthalmologist removes the vitreous body and replaces it with air or a saline solution that puts pressure on the retina to hold it in place. Vitrectomies are usually performed if there is a very large tear in the retina; if the macula is involved; or if blood that has leaked into the vitreous body is interfering with diagnosis or treatment.

See also Retinal cryopexy; Scleral buckling.

BOOKS

"Retinal Disorders." Section 8, Chapter 99 in The Merck Manual of Diagnosis and Therapy, edited by Mark H. Beers, and Robert Berkow. Whitehouse Station, NJ: Merck Research Laboratories, 1999.

"Retinopathy of Prematurity." Section 19, Chapter 260 in The Merck Manual of Diagnosis and Therapy, edited by Mark H. Beers, and Robert Berkow. Whitehouse Station, NJ: Merck Research Laboratories, 1999.