Is Radial Keratotomy Still Performed?

Key Takeaways

• Radial keratotomy was a common type of refractive surgery in the late 20th century but is now rarely performed.
• It’s considered outdated and has been replaced by newer procedures, including LASIK, PRK, and SMILE.
• Though radial keratotomy is generally considered safe and effective, many RK patients have experienced long-term effects. These include diurnal fluctuations and significant shifts toward farsightedness.
• An eye doctor likely won’t recommend RK surgery today, but they should be familiar with the procedure to understand the complications their patients might need addressing.

What is Radial Keratotomy Surgery?

Radial keratotomy (RK) was a commonly performed refractive surgery to correct myopia (nearsightedness). Though it was popular during the late 20th century, radial keratotomy surgery is now considered outdated.

RK surgery was developed by Russian eye surgeon Svyatoslav Nikolay Fyodorov in 1974. Now, more advanced and precise refractive surgery options have emerged.

Radial Keratotomy Procedure

When performing RK surgery, the surgeon uses a diamond knife to make 4 to 24 incisions in the cornea. These RK incisions flatten the steep central corneal curvature that causes myopia (nearsightedness). 

Different numbers, types, and patterns of RK incisions may be used. The most common approach involves eight incisions.¹ Deep incisions are necessary to effectively correct the refractive error.

Eye surgeons typically operate on one eye at a time. They will then wait to monitor the progress and see if vision has improved. These observations of the healing process determine how to proceed with the other eye.

Recovery and the Postoperative Period

The incisions made during surgery heal slowly and incompletely. The unpredictability of wound healing is one of the main drawbacks of RK. This is why surgeons only operate on one eye at a time. They often wait up to six weeks before operating on the second eye.

Many RK wounds don’t heal for years after the surgery. These chronic wounds have a risk of infection the entire time.

Is Radial Keratotomy Still Performed?

When it was first introduced, RK surgery received recognition for its ability to help correct myopia. Radial keratotomy has become an outdated procedure, and it’s rarely performed anymore. Today, more accurate and stable refractive surgeries are available to treat vision problems. 

 These other types of refractive surgery include:

• Photorefractive keratectomy (PRK)
• Laser in situ keratomileusis (LASIK)
• Small incision lenticule extraction (SMILE)
• Intraocular lens surgery

However, this doesn’t mean that knowledge of radial keratotomy is wrong or irrelevant. Ophthalmologists should be familiar with the procedure because many people have already undergone RK surgery. Some of them may need visual rehabilitation due to radial keratotomy complications.

Potential Radial Keratotomy Complications

Radial keratotomy is considered reasonably safe and effective, but it has a higher risk for complications than newer types of refractive surgery, such as LASIK.⁴

Potential complications include:

Hyperopic Shift

A 10-year follow-up study showed that more than 40% of people who had undergone radial keratotomy surgery experienced a gradual shift toward farsightedness (hyperopia).⁴ This is known as a hyperopic shift.

Progressive hyperopia causes people to require stronger prescriptions for corrective lenses throughout life. Many patients need additional vision correction (glasses or contact lenses) years after radial keratotomy.

Diurnal Fluctuations

Most patients who undergo RK experience fluctuating vision throughout the day (diurnal fluctuation). This is because a post-RK cornea tends to flatten during sleep and gradually steepen during the day. The cornea plays a key role in attaining clear vision.

Diurnal variations are typically most noticeable in the first few hours after waking up. This condition isn’t treatable.

Irregular Astigmatism

Astigmatism is a common refractive error that occurs when the cornea has an irregular curvature. An irregular astigmatism can be treated with rigid gas-permeable contact lenses.

Other Complications

Other complications from radial keratotomy may include:

• Weakened cornea
• Ocular infections and inflammation
• Vision loss
• Starburst patterns

What Are the Long-Term Effects of Radial Keratotomy?

When this refractive surgery was first introduced, RK patients were very pleased with the results. Although it initially provided a solution to myopia, negative side effects have been reported over time.

Long-term effects of radial keratotomy include:

Decreased Visual Acuity

In a study led by the National Institutes of Health, investigators found that 3% of post-RK eyes lost 2 or more lines of best-corrected visual acuity.¹ Reduced vision tends to shift in a hyperopic direction (farsightedness).

Dry Eye

Corneal incisions during the RK procedure can damage the nerves affecting tear production. This can result in dry eye.

Other Vision Problems

Individuals who underwent the operation also have described experiencing the following visual disturbances:

• Lower contrast sensitivity
• Halos 
• Hazy vision
• Glare
• Poor night vision

Alternative Eye Surgeries to RK Keratotomy

Several other refractive procedures can correct vision more accurately and with less risk of serious complications. These include:

• Photorefractive keratectomy (PRK). This procedure uses a laser to change the shape of the cornea to make the eye bend (refract) light correctly and improve vision.
• Laser in situ keratomileusis (LASIK). This procedure also uses a laser to reshape the cornea but involves cutting a corneal flap.
• Small incision lenticule extraction (SMILE). The eye surgeon uses a femtosecond laser to form a round piece of tissue (a lenticule) in the cornea’s inner layer. To remove the lenticule, they make a small incision in the cornea.
• Intraocular lens surgery. This type of surgery includes the placement of artificial lenses to resolve problems caused by myopia, hyperopia, and astigmatism. It’s similar to cataract surgery.

What Is the Difference Between LASIK and Radial Keratotomy?

Both radial keratotomy and LASIK correct refractive errors. However, there are many differences between the two vision correction procedures. These include:

• LASIK is less invasive and more accurate. It has a shorter recovery time and less risk of complications.
• LASIK is performed with a laser. This laser removes tissue from the central cornea.
• You can get LASIK on both eyes in the same session. This differs from radial keratotomy, which can only be done on one eye in one session.

Can You Get LASIK After a Radial Keratotomy?

An eye surgeon may not prescribe LASIK for people who underwent radial keratotomy and now face vision problems.

Instead, photorefractive keratectomy may be a more suitable and less invasive procedure in these cases. It is best to consult a surgeon to understand all options available.