Corneal cross-linking is which is done to treat an eye disorder called keratoconus. In Keratoconus, the bilateral ocular disorder arises as the stromal collagen tissue gets thin over time resulting in cornea taking up a conical shape. The bulge created due to the conical shape of the cornea distorts the vision and makes it difficult to see. Although the chances of a person getting keratoconus are less, as the frequency of it happening is to 1 in 2000 people. It can starts anytime when puberty begins progresses until thirty to forty years of age, when it is usually diagnosed. In corneal cross-linking, the eye surgeon uses special eye drops and ultraviolet A (UVA) light in order to repair the corneal tissues and make them stronger. to make the tissues in your cornea stronger. Ths the bulging, thereby improving the vision. The surgery is called “cross-linking” as it crosses links and strengthens the network of collagen fibres in your eye. Currently, Corneal collagen cross-linking is the only quality treatment to treat a thinning cornea and improve the distorting vision. Corneal cross-linking may also avoid the need to get the corneal transplant done which is which is a major and complicated surgery. Keratoconus is detected with the help of a slit lamp examination and the diagnosis can be confirmed by corneal topography.
The following patients are considered to be the eligible for corneal collagen cross-linking.
• The patient should be diagnosed with keratoconus with documented progression of the disorder.
• Patient's corneal thickness must be at least 400 microns.
• The patient should have good overall health.
• The patient should not be pregnant.
There are two types: epi-off and epi-on. “Epi” is is used for epithelium, the tissue that covers your cornea. In the epi-off technique, the epithelium is removed before the doctor puts the drops in. This allows the eye to absorb the vitamins and light better. However, this may have a little risk in the future. In the epi-on technique, the doctor does not touch the epithelium. Therefore, there is lesser pain and a short recovery.
Before starting with the corneal collagen cross-linking treatment, the surgeon administers topical anaesthesia to the patient in a sterile environment. The doctor then begins with gently removing the patient's corneal epithelium. Following this, the surgeon applies a Riboflavin solution every 5 minutes for the first half an hour. After this, the doctor exposes the patient's cornea to UVA light for about 30 minutes. The total treatment lasts for about an hour is painless. In the end, the eye is patched. The cornea is the clear, dome-shaped surface of the front of the eye which allows light to pass into the eye and provides focus to see images clearly. The loss in the corneal transparency results in loss of vision.
The corneal collagen cross-linking treatment depends on the type of treatment technique you opt for. In the epi-on procedure, the procedure is painless and recovery is short. Where you can be able to resume your regular activities the next day including ear contact lenses. In the epi-off procedure, there may be some pain for the first several days of the surgery. It may take up to 7-10 days before you resume your routine activities but for the epithelium to completely heal, it can take several weeks. After epi-off surgery, the doctor will prescribe antibiotics and steroid eye drops for up to 2 weeks. You will able to wear regular contacts after 2-4 weeks after the corneal cross-linking surgery, but the vision will change over 3-6 months.
Like other surgeries, epi-off corneal cross-linking surgery can have a few risks and complications which include:
• Mild eye infection
• Eye pain and swelling
• Corneal or epithelium damage
• Blurred or hazy vision.
The epi-on corneal cross-linking procedure doesn't have any risks or side effects.