Radial keratotomy (RK) is a type of eye surgery that is used to correct nearsightedness and was developed in 1974 by a Russian ophthalmologist, Svyatoslav Fyodorov.
In the 1980s and early 1990s, radial keratotomy was a popular refractive surgical procedure that served to correct nearsightedness. In total, several hundred thousand procedures were performed worldwide to help people with myopia.
What is Radial Keratotomy or RK Eye Surgery?
Radial keratotomy (RK) is a surgical procedure where radial incisions are made in the cornea for the purpose of flattening the shape. There are different protocols that are used to tackle different severities of myopia. This procedure often had Astigmatic Keratotomy (AK) performed if the patient also had astigmatism.
Patients were initially very pleased with the refractive results but, over time, they developed hyperopia and irregular astigmatism.
There are some people who, after getting RK surgery, experience fluctuations in their vision. Corneal cross-linking can reduce the problem of fluctuations in vision.
Radial keratotomy has since been replaced by other more improved and computer-controlled next-generation refractive surgeries, such as photorefractive keratectomy (PRK) and laser-assisted in situ keratomileuses (LASIK), for their better outcome quality.
Radial Keratotomy Procedure
The surgeon uses a diamond knife to create 4 to 24 cornea incisions, in order to change the focusing power of the anterior corneal surface. the change in refractive power of the cornea is achieved by flattening the steep central corneal curvature seen in myopic eyes.
In an RK procedure, a surgeon makes small but deep incisions (keratotomies) in the cornea with the goal of flattening it. Since myopia often results from an excessive curvature of the cornea, this procedure will ideally help to reduce issues like nearsightedness and astigmatism.
An eye doctor makes a small but deep incision of a specific pattern in the cornea. The diamond knife is used to make an incision that reaches a depth of around 90 percent of the total corneal thickness. A deep incision is necessary to flatten the corneal surface seen in myopia.
The number of incisions (ranging from 4 to 24) and the pattern of the cut are determined on the basis of required flattening of the cornea to treat nearsightedness and astigmatism.
In order to help correct vision in both eyes, many eye surgeons will perform RK surgery on one eye and then wait for six weeks before performing surgery on the other.
This delay allows the surgeon to observe the first eye and record the results of the surgery.
The results of the surgery on the first eye will often influence how the surgeon performs the surgery on the second eye.
Meanwhile, the patient will be fitted for contact lenses for their uncorrected eye to ensure equal vision between both eyes.
Post Radial Keratotomy (RK) Surgery and Healing
RK surgery takes about 15 minutes and can be done with the patient awake. Eye drops are used to anesthetize the cornea, meaning that there is minimal pain during the procedure. Following surgery, people feel moderately uncomfortable and will often require oral pain medication for 3-5 days.
Antibiotic eye drops need to be taken for about a week. You may begin to see the clear vision the day after surgery.
The cuts made during surgery heal slowly and can take years to fully repair themselves. RK wounds that don’t heal quickly often have a risk of infection anytime.
Patients who undergo RK surgery will become more and more farsighted as the years go by. After radial keratotomy, many patients need further vision correction years later.
RK Surgery Indications
Radial keratotomy or RK eye surgery is indicated in the eyes with mild to moderate myopia with or without astigmatism.
Radial Keratotomy Complications
RK surgery has shown to be great in the early days but has its long-term visual limitations. Many patients are left with permanent vision damage and other long-term complications. Some of the side effects and complications of radial keratotomy (RK) consist of changes to visual, anatomical, physiological, and optical aspects of the eye.
Irregular Astigmatism
Due to the varying impact of each hand-made RK cut on the cornea and its fluctuating status, it can lead to irregular astigmatism that is difficult to measure and treat due to its shape and visual effect.
The patient may require specialty contact lenses to achieve their visual potential.
Specialty contact lenses are specially designed for people with specific sorts of sight problems, such as keratoconus, irregular astigmatism. They can be prescribed by an optometrist and are worn over the eyes to offer improved vision.
Light Sensitivity
Some patients have reported that the incisions made during RK surgery extend into their pupil or visual axis. In these cases, they may experience mild to severe light sensitivity or photophobia and require dark glasses to help make their symptoms more manageable.
Potentially weak cornea and risk of rupture
These RK incisions were 95% deep into the cornea, making it a potential source of weakness in the eyeball. This could make any trauma or disorder more severe.
The extent of the damage caused by the incision of RK surgery often depends on the extent of the original surgery. If a patient has more severe myopia, they often need to have deeper and longer incisions. These cases result in more symptoms such as weakening corneas.
RK incisions never heal completely, so any type of trauma can reopen or rupture them and cause serious problems. This is due to the fact that any sort of trauma to your eye can lead to infection, astigmatism, or even worse.
Patients who have gone through RK surgery are urged to wear protective eyewear during any activities where their eyes may be at risk.
Prone to Eye Infection or inflammation
RK incisions heal slowly, which makes a patient more susceptible to infection and irritation. This can happen even with minor injuries, such as rubbing your eyes.
Surgical incisions can often be followed by the emergence of vessels that grow into or through the incision. This can result in corneal damage or even vision impairment.
Corneal Ectasia
Excessively deep and irregular RK cuts can lead to many problems. Not only might you end up with an irregularly shaped cornea, but it also may be thin and weak. This means that your eyesight may not be as good due to visual distortion and compromised structural integrity. This condition is also known as iatrogenic or surgical keratoconus.
Corneal Scars
Different types of healing RK cuts with intersecting patterns can cause scarring in the cornea, which can impact vision by distorting your corneal shape and by blocking light. This can result in distorted vision.
RK is a complication-prone surgery with many risks. in addition to the above-mentioned complications, RK patients usually suffer from dry eye, double or triple vision, fluctuations in the quality of their vision, halos, glare, starburst pattern, reduced indoor and night vision, and even depression.
Studies have shown that, over time, after RK for nearsightedness, a patient’s eyes gradually shift to farsightedness.
Treating Radial Keratotomy (RK) Surgery Complications
Custom-made scleral contact lenses can help restore your vision. The large lens goes over the sclera and covers the cornea with a fluid-filled vault.
The tear pool beneath the scleral lens compensates for the corneal surface irregularities, such as imperfections caused by an RK surgery. This helps to provide improved vision.
Scleral lenses are thin and permeable, letting oxygen through. They come with little to no discomfort, so patients hardly notice that they’re wearing them.
Is RK Eye Surgery Still Performed?
Radial Keratotomy has been declining in practice over the past decades. Newer, more accurate, and safer surgeries are available now to treat vision problems.
But the eye surgeons need to be familiar with the procedure as many patients who had already gone for this refractive surgery come for follow-up with complications.
Some patients may find themselves needing visual rehabilitation to regain their sight following the procedure.
If you’re considering getting a radial keratotomy, then you should consult your ophthalmologist first to see if they think it’s a good option for you.
Radial Keratotomy (RK) Versus Other Surgeries
These are some of the more advanced, accurate, and precise computerized alternatives to RK surgery that actually correct the refractive errors of wide ranges with lesser to no complications.
RK is a procedure that differs from these treatments in that it uses a blade to reshape the cornea‑ LASEK, LASIK, and PRK all laser-based treatments for the purpose of correcting defects in vision.
Similarly, RK surgery can correct mild to moderate myopia (with or without astigmatism) but other advanced laser refractive surgeries correct all types of refractive errors of any strength – myopia, hyperopia, and astigmatism.
Another big difference lies in the amount of cut or wound that is made on the cornea to flatten the corneal surface. All other laser refractive procedures are less invasive yet more accurate than RK surgery. The surgery can be done in both eyes on a single sitting without having to wait for several weeks to correct both eyes.
