Radial Keratotomy (RK) Surgery: Uses, Benefits & Complications

Radial keratotomy is a mostly outdated procedure in which a surgeon makes deep incisions to flatten the cornea and correct a person’s vision. 

Due to a number of common and relatively serious side effects, surgeons now use more modern alternatives such as LASIK and PRK. 

Why Is RK Surgery Not Widely Performed Anymore?

Radial keratotomy (RK) is a procedure that was developed in the early 1970s as a fairly effective refractive procedure. However, it comes with some distinct disadvantages, notably diurnal fluctuations, where a patient’s vision shifts over the course of the day.

As alternative procedures that can treat the same conditions were developed, such as LASIK and photorefractive keratectomy (PRK), RK became mostly outdated. The shifting vision most patients experience over the course of their day, combined with an overall shifting in their hyperopic direction over time, makes the surgery inconvenient and generally unnecessary.

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Potential Radial Keratotomy Complications

About 60 percent of patients who undergo radial keratotomy experience diurnal fluctuations. 

A patient’s cornea steepens over the course of the day, which then flattens as they sleep. As the cornea changes shape, the patient’s vision shifts with it. A person who experiences these fluctuations will see the most change in the initial hours after waking.

People who undergo RK can also experience a significant shift in their hyperopic direction over time, even years after their procedure. Research suggests over 43 percent see a shift of 1.00D or more. This may mean a patient requires several different eyewear prescriptions over the course of their life.

Other complications as a result of RK can include the following:

• Difficulty wearing some types of contact lenses
• Undercorrection or overcorrection
• Incorrectly placed incisions, leading to complications like slow healing and irregular astigmatism
• Microperforations of the cornea, leading to leakage and infection
• Very rarely, macroperforations of the cornea, which can result in the destruction of the eye

How to Repair Radial Keratotomy Complications 

One of the primary reasons doctors rarely perform radial keratotomy surgery anymore is that several of the above complications are irreversible. 

Diurnal fluctuations are lifelong, and corrective eyewear can become impractical. For a patient to keep their vision corrected throughout the day, they need multiple pairs of glasses.

Hyperopic shift also can’t be prevented, although it is more manageable. Regular eye exams and an updated eyewear prescription can make the shift a minor inconvenience for most patients. The biggest obstacle is potentially needing to purchase glasses more frequently than most people do.

A doctor can often treat undercorrection with further surgery. Overcorrection is quite rare and might be corrected with surgery or eyewear. In the vast majority of cases, surgeons will use more modern procedures for such corrections, not further RK surgery. 

Infected perforations can become serious if not caught early. They can be treated with antibiotic eye drops, potentially combined with anti-inflammatory drops. While very rare and generally the result of serious error, macroperforations may result in serious permanent damage, including loss of the eye. 

Scarring of the eye can cause visual symptoms that may be difficult to treat. A doctor can sometimes partially correct irregular astigmatism through special contact lenses or spectacles. 

Surgery can help as well, although the specifics are still being researched. A patient should talk to their doctor about the current risks and any unknowns. 

RK vs. LASIK vs. PRK

LASIK and PRK are the two closest procedures to compare to RK. A medical professional would rarely recommend radial keratotomy over these other two options.

LASIK is a form of refractive eye surgery that corrects vision by reshaping a patient’s cornea with a precise laser. While not without its own risks, LASIK is preferred to RK. 

PRK is a type of refractive surgery that uses a laser to reshape the cornea. It is a good option for patients who have dry eyes or thin corneas, where the risks of complications from LASIK may be too high. While complications with PRK are still possible, they can usually be treated without any permanent loss in vision. 

The biggest advantage of both these procedures over RK is that neither carries a meaningful risk of a person developing diurnal fluctuations, which happens more often than not with RK. 

Radial Keratotomy FAQs

What is the difference between LASIK and RK?

RK involves deep incisions so a surgeon can flatten the cornea. While this can treat conditions like nearsightedness and astigmatism, it also carries a high risk of the patient developing vision fluctuations. In a broad sense, it is somewhat similar to LASIK but not in the specifics.

LASIK is a more precise, modern process, reshaping the cornea so that incoming light is redirected. As an elective procedure, it has a fairly remarkable 95.4 percent patient satisfaction rate. Performed by a skilled surgeon and with proper follow-up, you are very likely to see a positive change in your vision and be happy with the results of LASIK. 

Is radial keratotomy safe?

All procedures carry inherent risks, but radial keratotomy was common practice for a time, and research suggests serious complications beyond diurnal fluctuations are rare. The procedure did what surgeons believed it did while it was in common use. Today, there are simply better alternatives available.

LASIK and PRK can both make similar or better changes to a person’s vision, with a similar or lower level of serious complications and without the high chance of vision fluctuations. RK is not dangerous, but it is likely a bad option for patients who can use alternative procedures to achieve the same vision corrections.

Can radial keratotomy be reversed?

Radial keratotomy is irreversible with modern surgical techniques. Core parts of the eye are altered surgically. However, this doesn’t mean a patient has no options for correction if complications occur.

If vision changes occur after RK, LASIK or PRK may be possible to correct vision. Glasses or contact lenses may also help. 

One challenge is correcting diurnal variations. A few options exist, such as using contact lenses, but research on the subject is incomplete. 

Talk to your doctor about what they think is best for your situation. Consider getting a trusted second opinion, as no set treatment exists as the dominant course of action for treating diurnal variations.

Is radial keratotomy still performed?

Radial keratotomy is largely an obsolete surgery. Modern alternatives achieve better results with fewer side effects and less risk.

References

1. LASIK World Literature Review: Quality Of Life And Patient Satisfaction. (April 2009). Ophthalmology.

2. LASIK — Laser Eye Surgery. (October 2020). American Academy of Ophthalmology.

3. Corneal Suture for the Correction of Hyperopia Following Radial Keratotomy. (June 2007). Journal of Refractive Surgery.

4. Diurnal Fluctuations in Corneal Topography 10 Years After Radial Keratotomy in the Prospective Evaluation of Radial Keratotomy Study. (July 1999). Journal of Cataract & Refractive Surgery.

5. Management of Corneal Perforations: An Update. (December 2019). Indian Journal of Ophthalmology.

6. Minimizing Radial-Keratotomy-Induced Diurnal Variation in Vision Using Contact Lenses. (November 2000). Journal of Cataract and Refractive Surgery.

7. Radial Keratotomy: Complications Management. (January 2022). American Academy of Ophthalmology.

8. What Is Photorefractive Keratectomy (PRK)? (April 2022). American Academy of Ophthalmology.

9. Long-Term Outcomes of Radial Keratotomy, Laser In Situ Keratomileusis, and Astigmatic Keratotomy Performed Consecutively over a Period of 21 Years. (March 2015). Case Reports in Ophthalmological Medicine.