Astigmatic keratotomy, also known as arcuate keratotomy or AK, is a procedure that corrects astigmatism.
Astigmatism occurs when your cornea’s curvature is not spherical like a basketball, but oval like an egg. As a result, one meridian (curvature) of your cornea is flatter, while the other is steeper.
AK is a type of corneal relaxing incision (CRI) surgery. These surgeries correct astigmatism by flattening the steeper areas of your cornea. This was done with diamond blades in the past but now is usually performed with a laser.
Pritish Kumar Halder explained that Astigmatic keratotomy eye surgery is done under local anesthesia and the entire procedure lasts a maximum of 10 minutes for both eyes. Read below:
Who Is a Candidate for Astigmatic Keratotomy Surgery?
Astigmatic keratotomy may be ideal for people who have:
- A desire to reduce their dependence on glasses or contact lenses
- Mild to moderate astigmatism
- Stable eyeglass prescription for at least one year
- Good general health; diabetes and connective tissue diseases may affect the healing process
- No eye problems that may affect recovery, such as severe dry eyes
Most times, AK is performed on people who have residual astigmatism after previous eye surgery, such as:
- Cataract surgery
- Corneal transplant (penetrating keratoplasty or partial-thickness corneal transplants)
- Radial keratotomy
What To Expect Before, During & After Surgery
AK is an outpatient procedure, meaning you can go home shortly after the surgery. The eye surgery itself only takes about 5 minutes per eye.
Before the procedure, the surgeon obtains a corneal topography. This serves as a map to guide the surgeon on where to make the incisions.
Another measurement called corneal pachymetry tells the surgeon how thick your corneal tissue is, which helps determine how deep the incisions can go.
To numb your eyes, the surgeon instills anesthetic eye drops. Then, they place a lid speculum to hold your eye open during surgery.
The surgeon places temporary markings on your cornea that indicate where they will make the incisions.
Traditionally, the surgeon used a diamond surgical blade. Many surgeons are now using a laser to create the incision, which may result in more precise outcomes.
The surgeon typically makes one or two incisions parallel to the edge of your cornea. These incisions are located along the steepest meridian of your cornea.
Generally, the deeper or longer the incision, the more astigmatism is corrected.
Shallower or shorter incisions result in less correction.
Reducing the distance between the two incisions also increases the amount of astigmatism correction.
AK tends to be more effective in older patients. The surgeon can make shorter incisions in these cases.
For younger patients, the surgeon may create longer incisions.
The surgeon prescribes antibiotic eye drops (and possibly steroid eye drops) to use for several days after surgery.
You may need to use eye shields to protect your eyes.
If you experience discomfort, you can take some over-the-counter pain relievers.
Other post-surgical symptoms include:
- Mild swelling
- Light sensitivity
- Scratchy eyes
These symptoms are normal and usually go away within a day or two. Full healing time is about 2 to 3 months, although your vision should improve within a day or so. Most people can return to work and resume normal activities the next day.
Side Effects of Astigmatic Keratotomy Surgery
Astigmatic keratotomy is considered safe and effective. However, a small percentage of people experience side effects that may be temporary or permanent.
Some side effects and complications include:
- Overcorrection or undercorrection
- Light sensitivity, glare, and halos, which can be permanent for some people
- Infection, although rare
- Weaker corneal structure, which makes your cornea more vulnerable to injury.