Radial keratotomy

Radial keratotomy is an eye surgery that is done to correct vision in individuals with nearsightedness (myopia).

The eye is covered with a clear layer of tissue called the cornea. The role of the cornea is to bend all the light passing through it towards the pupil, the dark hole at the centre of the coloured portion of the eye (iris). The pupil is behind the cornea and the natural lens of the eye is present behind the pupil. The light entering the pupil passes through the lens, which focuses the light towards the retina, a special tissue at the back of the eye. The special cells of the retina transmit the light as electrical impulses through the optic nerve to the region of the brain responsible for vision.

In individuals with nearsightedness, the cornea is very steep or the eye is longer than usual. In such people, the light rays coming from distant objects do not fall on the retina, causing the distant objects to look blurred. However, they can see near objects clearly.

Your doctor may recommend this surgery if you have stable, mild-to-moderate myopia in otherwise healthy eyes. Symptoms of myopia include:

• Headaches
• Eyestrain
• Difficulty seeing distant objects
• Squinting to see clearly

Radial keratotomy may also be recommended to correct vision in individuals with astigmatism. Astigmatism is yet another eye condition that occurs due to irregularities in the shape of the cornea. Symptoms of astigmatism include:

• Headaches
• Eye discomfort
• Eyestrain
• Blurry vision

A radial keratotomy is not recommended for those who have any of the following conditions:

• Nearsightedness that continues to get worse with time
• Changes caused by severe nearsightedness, e.g., retinal tears
• Pathological myopia (myopia that affects vision quickly)
• Any corneal disease
• Any tissue disease that might affect corneal healing post-surgery

The doctor may not suggest this surgery if your work involves driving or playing contact sports.

Your doctor should know about all the medicines that you take. As a part of the pre-operative preparation for the surgery, the surgeon may ask you to:

• Discontinue any blood-thinning medicines that you take a few days before the surgery.
• Take the morning medications for pain, blood pressure, and heart-related diseases with a small amount of water on the day of the surgery.
• If you have high blood pressure and diabetes, take medicines or insulin only with your doctor’s permission on the day of the surgery.

Other preparations include:

• Do not drink or eat anything after midnight the night before the surgery.
• You need to make an arrangement for someone to drive you home after the surgery.
• Wear loose, comfortable clothes to the hospital for the surgery. Do not wear any jewellery or other valuable items, nail polish, and eye makeup.
• Arrange a family member or friend to help you at home for a day after surgery.

A radial keratotomy is an outpatient procedure, i.e., you will be discharged on the same day of surgery. It is mostly performed in the surgeon’s office itself. The surgery involves the following steps:

• The surgeon will administer local anaesthesia (eye drops) to numb your eye.
• He/she will use an intraocular lens hook, a blunt instrument and make depressions on your cornea to mark the area for incisions.
• The surgeon will use a special instrument to measure the thickness of your cornea.
• He/she will use a special blade (the length of which is adjustable in micrometres) to make radial incisions on the markings. These incisions will flatten your cornea.
• After making the incisions, the surgeon will use a special fluid to clean them. This will minimise the number of epithelial cells, blood, and foreign bodies in the area.
• Finally, the surgeon will flood your eye with antibiotics to prevent infection.

It takes approximately 15 minutes to complete the procedure on one eye. The surgeon will initially perform the surgery in one eye and wait for the results for up to 6 weeks before performing the procedure on the other eye.

• You can expect the following during the recovery period after surgery:
• You may experience the following symptoms for one to four days after surgery:
  • Mild discomfort
  • Throbbing pain
  • A feeling of something in the eye
• The surgeon will prescribe medicines for pain relief. In addition, eye drops may also be prescribed to reduce swelling or prevent infection.
• You may be asked to wear a contact lens or an eye patch.
• You may experience a blurred vision for a few days or weeks after the surgery. The surgeon may ask you to not drive until your vision is normal.
• You may be able to resume your daily activities within a few days of surgery.
• Avoid doing activities that allow water to enter the eyes for two weeks. The surgeon will advise you when you can resume showering after surgery.
• Avoid eye makeup and vigorous activities for the next two weeks after surgery.
• You may experience a slight variation in vision throughout the day for three months and up to a year.

When to see the doctor?

You should contact the surgeon if you observe any of the following symptoms:

• Double vision
• Glare at night
• Intense eye pain
• Headache
• Vomiting or nausea
• Blurred vision

Radial keratotomy is considered to be a safe surgery. However, the surgery reshapes the cornea, making it difficult to wear contact lenses thereafter. It also weakens the cornea, making it more prone to injuries. Some common complications that could occur after the surgery include:

• Nearsightedness, even after surgery
• Farsightedness
• Unstable vision 

Some less-commonly occurring complications include:

• Double vision 
• Your vision may be less than what you could have achieved by wearing contact lenses or glasses
• Loss of depth perception (inability to orient objects with respect to each other)
• Difficulty seeing things in bright light (glare) during the first three to six months post-surgery (especially at night, which makes it difficult to drive at night)

Some rare complications associated with the surgery include:

• Infection of the cornea
• Glaucoma
• Puncture of the cornea

After surgery, the scars left on the cornea may cause problems while undergoing other eye surgeries in the future. This surgery has now become largely obsolete and is replaced by LASIK surgery.

You may have a follow-up visit a day after the surgery where your doctor will examine your eye. You may also have multiple follow-ups throughout the year after that.

Disclaimer: The above information is provided purely from an educational point of view and is in no way a substitute for medical advice by a qualified doctor.