Radial Keratotomy (RK) for Nearsightedness
Radial keratotomy (RK) involves making tiny cuts in the cornea, which flatten it and reduce nearsightedness. In people who have both astigmatism and nearsightedness, the surgeon may make additional cuts to flatten the misshapen part of the cornea that is causing the astigmatism.
Because the outcome of surgery on the first eye may affect how surgery is done on the second eye, many surgeons wait 6 weeks before treating the second eye. This delay also reduces the risk of spreading a corneal infection to the second eye. While waiting for the second procedure, you are usually fitted with a contact lens for the eye that is still nearsighted, since wearing two very different eyeglass prescriptions causes distorted vision.
What To Expect After Surgery
RK is an outpatient procedure. It is done under local anesthesia in a surgeon's office or a same-day surgery center. The operation on one eye takes about 10 to 15 minutes. The entire process usually takes less than 2 hours, including preparation time, care right after the surgery, and paperwork.
After surgery, you may wear a patch or contact lens on the eye and get a prescription for pain medicine. Someone must drive you home and then back to the surgeon's office the next day. During this second visit, the surgeon will examine your eye and prescribe eyedrops to prevent infection and reduce inflammation. More follow-up visits are required, usually the next week and then throughout the first year after surgery.
Unstable vision is common in the first 3 months after surgery and may last for up to 1 year. Your vision may vary slightly over the course of a day (although not to the point that you would need two pairs of glasses).
Why It Is Done
Radial keratotomy is an elective procedure that is done to correct nearsightedness in otherwise healthy eyes.
Good candidates for RK have normal, healthy eyes with stable, mild-to-moderate nearsightedness (up to about 3 diopters) that is not getting worse with time. RK may also correct some amount of astigmatism.
You may not be eligible for RK if you have:
How Well It Works
RK is effective in reducing mild-to-moderate nearsightedness. It does not always completely end nearsightedness. You may still need to wear corrective lenses some of the time for either near or distance vision (or both) after surgery. People who have moderate-to-high nearsightedness before surgery are more likely to still need correction for distance vision after surgery than those who are only mildly nearsighted.
The greatest problems with RK surgery are that the results are harder to predict and they tend to change over time. RK reduces nearsightedness, but it often causes mild farsightedness (overcorrection) or does not completely correct nearsightedness (undercorrection). Results are sometimes several diopters different than predicted. In contrast, eyeglasses and contact lenses are fitted with an accuracy of within 0.5 diopter of the desired correction.
The most frequent complications of RK include overcorrection (farsighted after surgery), undercorrection (still nearsighted after surgery), and unstable vision (hyperopic shift). Retreatment is sometimes desired to correct these problems. You may not be able to wear contact lenses because of the shape of the eye after surgery. This is not the case with LASIK or PRK.
Complications can occur but are not common. These include:
A few very rare complications may threaten vision, including:
Radial keratotomy is considered safe. No deaths have been reported as a result of the operation. And serious complications are rare. But experts do not yet know the long-term side effects or complications.
What To Think About
If you are considering having surgery to improve nearsightedness, consider all the options (including radial keratotomy, PRK, LASEK, epi-LASIK, LASIK, corneal ring implants, and intraocular lens implants), and talk about them with your doctor. Ask your doctor the questions that you have about surgery (for example, what are the risks, benefits, and possible outcomes) so that you understand your options and can make the best decision.
PRK, LASEK, epi-LASIK, and LASIK surgery have replaced radial keratotomy (RK) as the refractive surgeries chosen by most people. But RK is still very effective for mild nearsightedness (up to 3 diopters) and in other cases. Corneal ring implants help some people who have low levels of nearsightedness.
If you need another type of eye surgery later in life, such as cataract removal, the corneal scars from RK may make the operation and recovery more difficult. RK weakens the cornea, making it more prone to injury.
The RK surgery is an elective procedure. The cost of refractive surgery varies in different locations, but it can be very costly. Most insurance companies do not cover the cost of refractive surgery.
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