Introduction  

Radial keratotomy is a surgical procedure that focuses on correction of the corneal curvature. The surgery dates back to the 1970s when it was first performed. It grew in popularity in the 1980s and 1990s. However, other advanced refractive surgeries took over soon after. More recent procedures include the LASIK, PRK and LASEK. They utilize laser technology to make incisions on the cornea.
Radial keratotomy requires proper case selection and a meticulous technique for operation. It involves use of a highly precise diamond blade which cuts through about 90% of the corneal thickness. The cornea has five layers including the epithelium, Bowman’s membrane, stroma, Descemet membrane and the endothelium. The thickness of the cornea is essential to determine the length of the blade. The surgery works by flattening the central portion to bring focal point closer to the retina. Ultimately, distance vision improves.
It is not suitable for patients with pathological myopia, abnormal corneal thickness, inflammatory diseases, and many other corneal disorders. Eye assessment is necessary before undergoing the surgery.

Purpose

The surgery was indicated primarily for patients with mild to moderate nearsightedness (myopia). Myopic individuals are able to see near objects clearly but have trouble focusing on distant objects. The condition is mostly inherited but can also develop in adulthood. The incisions made during surgery cause the corneal sides to bulge out, thereby flattening the central part. The result is usually sharper near vision. 
A mild asymmetric radial keratotomy (M.A.R.K) can also be performed in cases of keratoconus. This is a condition in which the corneal layer bulges out. The surgery is only performed on the area affected. It significantly improves vision in the patients.
Some cases of astigmatism have been successfully corrected using radial keratotomy. Astigmatism is present where the cornea has an irregular curvature. Vision appears blurry and sometimes distorted. It can occur together with myopia.

Preparation and Expectation Before Surgery
The eye doctor will conduct some evaluations to determine whether the patient is eligible for radial keratotomy. One is considered a good candidate if:
They have mild to moderate myopia - The acceptable diopter range is 1.50 to 6.00. Anything outside the limits may cause over or under correction.
Their nearsightedness is not getting worse – Unstable refraction is common in patients younger than 21. The surgery is likely to not be effective in such cases.
They don’t have any pathological conditions that affect the surgery or healing.
Patients should not wear makeup or contact lenses on the day of surgery. They should also have someone to drive them home after the surgery.

Preparation and Expectation Before Surgery

The eye doctor will conduct some evaluations to determine whether the patient is eligible for radial keratotomy. One is considered a good candidate if:

  • They have mild to moderate myopia - The acceptable diopter range is 1.50 to 6.00. Anything outside the limits may cause over or under correction.
  • Their nearsightedness is not getting worse – Unstable refraction is common in patients younger than 21. The surgery is likely to not be effective in such cases.
  • They don’t have any pathological conditions that affect the surgery or healing.

 

Patients should not wear makeup or contact lenses on the day of surgery. They should also have someone to drive them home after the surgery.

Procedure

Radial keratotomy is a straightforward procedure. Once the patient’s eye has been numbed using local anesthesia, the surgeon makes the incisions. The lines of the cut are made to diverge from a central hub, resembling the spokes of a wheel. It takes about 10-15 minutes to get the surgery done for a single eye. The whole process, including preparation, procedure, and aftercare may take about 2 hours. Usually, the second eye is operated on after 6 weeks or so. The outcome of the first eye determines how and if the next surgery will be done. After the operation, a contact lens is fitted on the eye which is still nearsighted.

After Care, Recovery, Results

Recovery after the surgery may take a few days. The patient can expect to have some mild discomfort, pain, and blurry vision for a week or so. Doctors instruct the patient to not engage in vigorous sports. Make-up should also be avoided the first few days after the operation. A patch or contact lens is usually given, together with pain medication, antibiotic eye drops, and anti-inflammatories.
The patient is required to go for a second visit the following day after surgery for monitoring. More visits should be done the following week and throughout the first year of surgery. 

Risks & Complications 

Although the surgery is usually a success in most cases, a few risks/complications involved include:

  • Overcorrection – The surgery may result in mild farsightedness instead of normal vision. This is common where the patient had little myopia.
  • Undercorrection – The patient may end up with vision that is not completely corrected. It is likely to happen where there’s too much myopia.
  • Glares and halos around lights – This especially occurs at night. The patient experiences glare and sees halos around lights. It is common in the first three months and may go on for up to the 6th month.
  • Irregular astigmatism – This may also cause double vision.
  • Unstable vision

 

Other adverse complications could include:

  • Corneal perforations
  • Infectious keratitis
  • Stromal melting
  • Cataracts
  • Glaucoma
  • Endophthalmitis
  • Retinal detachment