A yttrium aluminum garnet (YAG) capsulotomy is an outpatient laser surgery performed by an ophthalmologist on a patient who has previously had cataract surgery — the removal a cloudy lens from the eye. The surgeon first opens the elastic bag, or capsule, surrounding the lens in the anterior portion of the bag. He or she removes the foggy lens from the bag, which is left in the eye to secure the artificial lens implant in place. If the bag clouds up at any time after cataract surgery, the YAG capsulotomy perforates the center of the bag behind the implant, creating a hole and producing a clear window for unobstructed vision.
About 20 to 25 percent of cataract surgery patients develop fibrosis or haziness of the capsule. It may appear within months of the surgery, or it may take several years to develop. The incidence and frequency of the posterior capsule clouding depends on several factors, including the degree to which the bag was cleaned in the original surgery, the age of the patient, and the implant material.
Not all of the cases require YAG capsulotomy. Eye surgeons reserve laser treatment for those who experience visually significant symptoms related to the cloudiness. Commonly described symptoms of advanced capsule clouding include blurred vision, double vision, decreased ability to distinguish between shades of gray, and glare — especially with night driving. Glare testing can be performed in the ophthalmologist's office to ascertain the degree to which the capsule haze is impacting a patient's vision.
A YAG posterior capsulotomy is accomplished in an office setting at a machine that resembles the slit lamp used by the ophthalmologist to examine the eye. The procedure is painless and does not require anesthesia. After the pupil is dilated, the treatment can usually be completed in less than five minutes. The vision may improve instantaneously, or it may gradually clear over a few days. There are usually no activity restrictions during the recovery period.
The potential benefit of enhanced vision must be weighed against the risks of YAG capsulotomy. Risks include increased eye pressure, damage to the implant, bleeding in the eye, and retinal detachment, which is a separation of the thin inner layer of the back of the eye from its underlying nourishment layer. Overall, complications occur in very few cases, and the risk of retinal detachment is about two percent. In the vast majority of cases, the benefits of YAG capsulotomy far outweigh the risks.