Astigmatic keratotomy (AK) is a procedure for reducing astigmatism by reshaping the cornea from an oval shape into a more spherical shape. It is an elective procedure since it is not always necessary and not urgent. When AK is successful, patients may not need to wear eyeglasses or contact lenses again. In cases in which corrective eyewear is still needed, thinner lenses are typically effective.
Preparing for an Astigmatic Keratotomy
In general, people who are preparing for an astigmatic keratotomy are asked to:
- Avoid make-up, especially around the eyes on the day of surgery
- Eat a light meal before surgery begins
- Discontinue wearing rigid gas-permeable contact lenses three weeks prior to surgery in order to ensure precise preoperative measurements; no lenses of any kind should be worn for at least three days prior to surgery.
- Arrangement for a ride home is necessary after this procedure.
- Adequate time off for rest will be needed after surgery
In preparation for an astigmatic keratotomy, your eye doctor will take a complete medical history of you. Your eyes will be tested to check the corneal thickness, refraction, and pupil size. These steps are taken to ensure you are a good candidate for this procedure.
Astigmatic Keratotomy Process
Astigmatic keratotomy is rarely if ever performed after LASIK or Photorefractive Keratectomy because those procedures usually take care of the astigmatism or can be repeated if residual astigmatism is still present; however, it is sometimes preformed along with cataract surgery, if necessary.
Your eyes are measured during pre-operative testing in order to determine where the incisions should be made. During the actual procedure, your eyes are numbed with anesthetic drops, and marks are made on the cornea to indicate where the incisions should be made. The procedure changes the curvature of the cornea, making it more spherical. Typically, this procedure takes twenty minutes or less to perform. Antibiotic drops are applied to prevent infection, and sometimes medicine is prescribed for side effects like scratchiness or foreign-body sensation.
Normal activities can usually be resumed within two days, and vision improvement tends to become noticeable within two weeks. If vision improvement is not noticeable, patients should not assume that the procedure was unsuccessful; in some cases, recovery may take longer. It is always best to ask your eye doctor what results to expect.
Astigmatic Keratotomy Candidates
People are best suited for astigmatic keratotomy if they have mild or moderate astigmatism, have not had prior major eye problems, have had a stable eye prescription for at least a year, and want to be free from astigmatism without the need for contacts or eyeglasses. With LASIK eye surgery’s high rate of success in correcting astigmatism, the use of astigmatic keratotomy has declined significantly among refractive surgeons.
Advantages of Astigmatic Keratotomy
Advantages of this surgery include:
- Safe, inexpensive procedure
- Very effective in correcting astigmatism
- Great alternative surgery for those with mild astigmatism, congenital astigmatism, astigmatism with a cataract, post-traumatic regular astigmatism, and astigmatism after corneal transplantation
- Can be combined with other refractive techniques
- May render LASIK surgery unnecessary
- Little to no discomfort felt during the procedure
Disadvantages of Astigmatic Keratotomy
Disadvantages of this surgery include:
- Prolonged healing time — typically about three months
- Irreversible outcome
- Discomfort for two to three days following procedure
- Not everyone is a good candidate for this procedure.
Side Effects of Astigmatic Keratotomy
Side effects resulting from this procedure are rare, but do occur in some people. Some patients experience an infection at the surgical site, whereas others suffer from a decline in vision for the first few months following surgery. Some people suffer from photophobia (sensitivity to light) following surgery. While this usually lasts only a few hours, it can sometimes be permanent. Some people experience a feeling of a foreign object in the eye. Typically, eye drops are prescribed to alleviate this feeling and to prevent infection and inflammation.
Any incision can weaken the cornea, although usually not enough to cause a problem. Significant weakening can occur, however, leading to a condition called ectasia, which is a bulging of the cornea. Ectasia can leave a person requiring glasses or contacts even after it stabilizes. In rare cases, ectasia can progress to a point where a corneal transplant is necessary to correct the patient’s vision. If contact lenses are still required following AK, it can sometimes be difficult to wear them due to fitting issues, so new eyeglasses may need to be prescribed instead.
Complications of Astigmatic Keratotomy
As with any surgical procedure, complications may arise. Complications after an AK include:
- Eye infection
- Dry eye
- Irregular astigmatism
- Recurrent astigmatism
- Corneal scar
- Ocular micro-penetration
- Loss of vision (very rare)
Talking to Your Eye Doctor
Here are some questions to ask your eye care professional about astigmatic keratotomy:
- Is AK the best procedure for my situation?
- Which other procedures do you recommend and why?
- What will happen next if this procedure fails?
- Is this procedure typically covered by insurance?
- MDConsult Yanoff & Duker: Ophthalmology, 3rd. ed. Radial Keratotomy http://www.mdconsult.com/books/page.do?sid=1154367648&eid=4-u1.0-B978-0-323-04332-8..00017-2--s0140&isbn=978-0-323-04332-8&uniqId=2404577