Corneal cross-linking for keratoconus
Mr Tariq Ayoub - 28 Sep 2022
Corneal cross-linking is a standard treatment for keratoconus to prevent the condition from worsening. During this patient guide, we answer all your questions on corneal collagen cross-linking.
Corneal cross-linking
Collagen cross-linking is a process that occurs naturally as you age around your mid-thirties to early forties. The collagen in your cornea stiffens through exposure to UV sunlight, causing the collagen fibres to cross-link.
A corneal cross-linking (CXL) procedure involves chemically bonding corneal fibres to strengthen and stabilise the cornea. We often perform cross-linking surgery to prevent the progression of keratoconus and avoid corneal transplantation.
Cross-linking for keratoconus
Keratoconus causes your dome-shaped cornea to bulge into a cone shape. As collagen cross-linking usually occurs with ageing, many people find that their keratoconus stabilises as they age.
However, keratoconus often occurs in teenagers and those in their twenties, meaning they usually require medical intervention. Keratoconus treatment is suitable for most people over 18, as long as they meet the minimum corneal thickness and other suitability criteria. The criteria are stricter for laser refractive CXL than standard CXL. We explain what laser refractive CXL involves later on the page.
For more information on treating keratoconus, read our blog: Is laser eye surgery suitable for keratoconus? Keep reading to learn more about how the cross-linking procedure works.
CXL procedure
Before the procedure
On the day, we’ll need you to wear no eye makeup and arrange transport to and from the clinic.
Before we begin, we will cover what you can expect from the procedure. Feel free to ask any questions about CXL and how it works. As with all procedures, we will numb your eyes with eye drops to prevent pain.
During
There are two types of cross-linking: Epi-on and epi-off. Epi refers to the epithelium – the cornea’s surface layer. It protects the cornea by acting like a barrier against bacteria.
During epi-on, the epithelium is left intact but loosened with eye drops or a sponge. Epi-off involves removing the epithelium. At Oculase, we use a laser (PTK) to remove the epithelium as it improves the outcome of the procedure.
Once we’ve removed the epithelium, we place riboflavin (vitamin B2) drops into the cornea. The riboflavin is a photosensitiser, meaning it allows your cornea to absorb light better. It takes around 20 minutes to soak the cornea.
We then shine ultraviolet-A (UVA) light into your eye to activate the riboflavin, causing the bonding process. The entire procedure takes 30 minutes per eye.
Lastly, we place a contact lens over your eye to act as a bandage while the eye heals. Let us know if it falls out, but do not try to reinsert it yourself. If you require another, we will put this in for you. To aid the healing process, you’ll need to use eye drops as directed by your eye specialist.
After
You may experience some strong pain and blurry vision for a few days after the procedure as your epithelium heals. We will give you eye drops and painkillers to manage this. Contact us if you feel severe pain past the few days after your surgery.
Your eyes may also be sensitive to light for a few days. We recommend wearing sunglasses outside if it’s sunny. Do not rub your eyes for at least five days after the procedure. Ideally, you should avoid rubbing your eyes entirely, as it can cause keratoconus to progress.
We will arrange a follow-up appointment and explain how to care for your eyes after CXL. You will need to change your glasses or contact lens prescription when your eyes have healed.
Laser refractive cross-linking
While improved vision is not the focus in standard CXL, you may experience better vision as a result, as your vision is stabilised. Laser refractive CXL allows us to improve your vision as well as halt the progression of keratoconus. We tailor the treatment to your specific needs.
Watch our video below to learn more about using a laser during keratoconus treatment.
Benefits
Corneal CXL is a safe and effective procedure with a success rate of over 90%. Though, you must follow your eye specialist’s aftercare instructions. The most noticeable benefit is slowing or stopping the progression of keratoconus, preventing vision changes or loss.
Contact lenses are often hard to tolerate for people with keratoconus as the cornea thins and becomes misshapen. But, they should be more tolerable after CXL. Cross-linking also avoids the need for corneal transplants, which involves a more invasive procedure.
When you choose laser refractive cross-linking, we can also improve your vision and could reduce or regularise astigmatism.
Risks
Cross-linking complications are rare, though you should still familiarise yourself with them. Before the procedure, our eye specialist will provide a detailed explanation of the risks and discuss the likelihood of each.
Risks include
- Eye pain
- Stromal scarring
- Corneal damage
- Blurred or hazy vision
- An infection in the eye
- Damage to the epithelium
- Delayed epithelial healing
- Swelling or severe inflammation
- Infectious, ulcerative or herpetic keratitis
Frequently asked questions about CXL
Who should not have the cross-linking procedure?
If your corneal scans show the progression of keratoconus, we may recommend cross-linking. However, some may be more at risk of complications due to other factors. We call these contraindications. For these people, we might suggest an alternative treatment.
Contraindications:
- Pregnancy
- Autoimmune disorders
- Current ocular infection
- Neurotrophic keratopathy
- History of herpetic infection
- Severe corneal scarring or opacification
- Poor epithelial wound healing previously
- Severe ocular surface disease, such as dry eye
- Less than the minimum corneal thickness < 375 µm
Does CXL mean I won’t ever need a corneal transplant?
A cross-linking procedure can prevent the need for a corneal transplant. Though, around 20% of people ultimately require a corneal transplant.
How can I look after my eyes while I recover?
You may need to take up to a week off work while your eyes heal from CXL. Do not wear eye makeup during this time. For the next two weeks, also avoid strenuous activities, such as heavy lifting.
Can cross-linking treat any other condition?
Cross-linking is most commonly used for treating keratoconus, though it could also be used to treat the following conditions.
- Corneal ectasia
- Infectious keratitis
- Post-LASIK ectasia
- Corneal ulcers and oedema
Book a consultation
In the early stages of keratoconus, we may recommend corneal cross-linking. Our eye specialist, Mr Tariq Ayoub, has a wealth of knowledge in keratoconus treatment. Book an appointment today to assess your condition and receive an expert treatment recommendation.
