What is AK?
Astigmatic keratotomy (AK) is a method of correcting astigmatism, which is a condition in which the curvature of the cornea (the clear part at the front of the eye) is greater in one direction than the other. It’s most commonly used after cataract surgery (or refractive lens exchange) or a corneal transplant, in order to correct astigmatism. The procedure may include limbal relaxing incisions (LRI) or corneal relaxing incisions (CRI); limbal relaxing incisions are nearly always preferred, and the terms “astigmatic keratotomy” and “limbal relaxing incisions” are used more or less synonymously. Uncomplicated astigmatism is more commonly treated with LASIK or another laser vision surgery, or with phakic IOLs.
If you’re choosing refractive surgery, make sure you’re choosing it because you really want it, not to please someone else or to fit an imagined ideal. No one else can make the choice for you; it’s your body, and you’re in charge of it. After you do your research and understand the procedure, if you believe that AK is right for you, then proceed. To help you in your decision-making process, we have some information about the risks and benefits of AK at Astigmatic Keratotomy (AK): Risks and Benefits.
Please note that this page is for informational purposes only, and is not a substitute for qualified, individualized medical advice. You should discuss your potential elective procedure with your own doctor(s), including your primary care physician and the doctor who will perform your procedure if you decide to proceed.
How it’s done
If LRI is being performed in conjunction with cataract surgery or RLE, then it’s typically done at the same time, just before or after the procedure on the lens. Surgeons typically prefer to do the LRI first, but some surgeons prefer to do the lens exchange first and LRI afterwards.
You will receive several drops of numbing medication in your eye. Next, an eyelid holder will be placed that prevents you from blinking during the procedure. With the patient sitting upright, the cornea is marked to indicate the vertical axis (at 12 o’clock and 6 o’clock); this is necessary because the eye may rotate once the patient is lying down.
One or two small incisions are then made in the cornea. The incisions do not go all the way through the cornea, but partway through; the exact depth is determined by how much astigmatism needs to be corrected. The incisions will relax the cornea, allowing it to take a more rounded shape in that direction, and bringing the curvature of the cornea more into balance.
Limbal relaxing incisions (LRI) are almost always used. These are placed near the edge of the cornea, outside the field of vision. Sometimes, corneal relaxing incisions (CRI) are chosen, which are made closer to the center of the cornea. CRI has a greater ability to change the shape of the cornea, but it can lead to overcorrection and also to visual disturbances (because the incisions are located within the patient’s visual field), so CRI is rarely used and LRI is nearly always preferred.
After the incisions, your cataract surgery or RLE procedure may be performed. The incisions are not sewn closed, but rather are left to heal on their own; this allows the cornea to reshape, as desired. A protective shield will be placed over the eye.
Preparing for the procedure
Choosing your surgeon
When choosing an eye surgeon for your refractive surgery, you want a highly-trained professional with experience in this type of surgery. A fellow of the American College of Surgeons has received training in surgery (look for the acronym FACS), and a member of the American Board of Ophthalmology has training and experience specifically in the surgical and nonsurgical care of eye diseases. Also, choose a surgeon with whom you feel comfortable and safe, and who listens to you and tries to understand your goals. If you have friends who’ve had vision correction surgery, and you like their results, ask for a referral. While cost may be a consideration, don’t allow this to override more important factors in your decision. Your safety and the quality of your results are worth a little extra spending.
For more help in your search for a refractive surgeon, visit our How to Find the Best Refractive Surgeon page. At Doctor Review, you can also search providers for patient reviews to help you find the very best.
Getting ready for the procedure
For at least a few weeks before your refractive surgery, you’ll need to stop wearing contact lenses and switch to glasses. Contact lenses can distort your corneas by pressing on them, which could lead to inaccurate measurements, meaning that the outcome of your surgery won’t be ideal.
Also, in order to minimize the amount of debris that’s in your eye during your surgery, you should skip using any eye creams or makeup the day before and the day of your surgery. Otherwise, there could be buildup in your eye, leading to inaccuracies during your procedure.
After the procedure, you’ll need a family member or trusted friend to drive you home. You should plan to spend the rest of the day resting.
You will be given a transparent eye shield to wear over the treated eye(s). The shield is intended to remind you not to touch or bump your eyes, as any touching of the eye could damage the cornea and cause it to heal incorrectly. You will need to wear the shield full time for two days, and then should wear it at least at night for several more days, though wearing it during the day may provide extra safety for your eye. You will also be given eyedrops, which you will need to use several times a day; the drops keep your cornea moist as it heals, and help to prevent infection and inflammation.
It will take three to six months for healing of your eye(s) to occur. At this point, your vision will stabilize, and the side effects from the healing will resolve. If there is still astigmatism present at this point, then you may opt to have a second surgery to increase the depth of the incisions, which may bring your vision closer to ideal.