Radial Keratotomy

What is Radial Keratotomy Surgery?

Radial keratotomy (RK) is a refractive surgical procedure to address vision problems caused by myopia (nearsightedness). It first became popular in the United States during the 1980s after its development by Russian eye surgeon Svyatoslav Nikolay Fyodorov. 

The surgery consists of separate linear incisions which penetrate the thickest layer of the cornea (stroma). These RK incisions (ranging between 4 and 24) help to correct refractive error by changing the focusing power of the anterior corneal surface. In other words, there is a surgical flattening of the corneal curvature to improve visual acuity. 

However, more advanced and precise eye surgery options have emerged, and radial keratotomy has become uncommon. These other types of refractive surgery include:

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

Radial keratotomy, at its beginning, received recognition for its ability to help correct myopia. Yet, its risks of complications and long-term effects have outweighed the perks of such a procedure. Some of the negative consequences from radial keratotomy include, but not limited to:

• Irregular astigmatism 
• Vision loss
• A hyperopic shift or hyperopia (farsightedness)
• Starburst patterns

The cornea is responsible for about 66% of the eye’s refractive power. 

Radial Keratotomy Procedure Steps

The radial keratotomy procedure consists of different steps. The following is a breakdown of the ocular surgery:

1. The eye surgeon performs several incisions in the cornea in a specific pattern. Incision depth reaches around 90% of the corneal thickness.
2. A central “hub” is left untouched in the corner, and radial incisions stem outwards from this element. 
3. Because the number of incisions and hub size affect corneal flattening, the surgeon will determine how many incisions to make and modulate hub size accordingly. 

It is important to note that eye surgeons will operate on one eye at a time to see if vision has improved. Observations recorded of the healing process will determine how to proceed with the other eye. 

Pros and Cons of Radial Keratotomy

Radial keratotomy has become an outdated procedure, and its benefits do not outweigh the disadvantages associated with it. Although it initially helped provide a solution to myopia, negative side effects have occurred.

For example, in a study led by the National Institutes of Health, investigators found that 3% of eyes lost 2 or more lines of best-corrected visual acuity. 

Similarly, corneal incisions made during the RK procedure can damage the nerves that affect tear production and result in dry eyes. Individuals who underwent the operation also have described experiencing lower contrast sensitivity, halo, haze, glare, and more. Lastly, in a 10-year follow-up of RK patients, hyperopic regression occurred post-surgery. 

Additionally, radial keratotomy will not be the first choice listed in an ophthalmology clinic. Better, more precise refractive procedures are available, including LASIK.

Is Radial Keratotomy the Same as LASIK?

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

LASIK is a less invasive yet more accurate procedure than radial keratotomy. It does not have as long a recovery time as radial keratotomy, and complications are less likely. 

Additionally, individuals can undergo LASIK on both eyes in the same session. This differs from radial keratotomy, which can only be done on one eye in one session. 

An eye surgeon may not prescribe LASIK for individuals who underwent radial keratotomy and now face a deterioration in 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. 

Is Radial Keratotomy Still Performed?

Radial keratotomy is not as common as it was in the 80s and 90s. Other more accurate and stable refractive surgeries are available to treat vision problems. 

However, this does not mean that knowledge of radial keratotomy is irrelevant. Because many individuals have already undergone the procedure, ophthalmologists should be familiar with the procedure and its iterations. Some RK individuals may need visual rehabilitation due to unwanted effects caused by the procedure.  

Similarly, individuals should seek medical advice from their ophthalmologist about this option if highly interested. Radial keratotomy is ideal for those with mild to moderate myopia. 

How Much Does Radial Keratotomy Cost?

Little information about radial keratotomy costs is available because of the procedure’s lack of popularity. 

Also, insurance companies may not provide coverage for this surgery. Other refractive operations can resolve vision issues at a lower price and more efficiently. 

Alternative Surgeries 

The following is a list of alternative surgeries that can treat refractive errors more accurately and with less risk of long-term complications, including:

• Photorefractive keratectomy (PRK). This elective procedure uses a laser to change the cornea’s shape to make the eye bend (refract) light correctly and improve vision. Laser in situ keratomileusis (LASIK). This procedure is similar to PRK in that it uses a laser to improve vision. However, it is more invasive because the surgeon creates a corneal flap to reshape the cornea. 
• 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, the surgeon makes a small incision in the cornea. It is comparable to LASIK but with less dry eye and a more stable corneal structure.  
• Intraocular lens surgery. This type of surgery includes the placement of artificial lenses to resolve problems caused by myopia, hyperopia, and astigmatism.