Corneal cross-linking (for keratoconus) (Corneal collagen cross-linking (CXL))

What is corneal cross-linking?

Keratoconus is a condition where the clear front window of the eye (the cornea) becomes thinner and bulges into a more cone-like shape over time. This distorts vision and can make glasses and contact lenses harder to get right.

Corneal cross-linking uses riboflavin (vitamin B2) eye drops and a controlled dose of ultraviolet (UVA) light to create extra bonds between the fibres of the cornea, making it stiffer. The aim is to halt or slow the progression of keratoconus — in effect, to 'lock in' the shape your cornea has now.

It is important to understand what cross-linking can and cannot do. It is mainly about stopping things getting worse, not about improving your sight. Most people will still need glasses or contact lenses afterwards, and the treatment is usually only recommended when scans show the keratoconus is actually progressing. It does not cure keratoconus or reverse the changes already there.

Types, options & approaches

There may be different ways to do this. The right approach depends on the clinical question and your circumstances.

Options at a glance

These are the main approaches described in this guide. The right option depends on the diagnosis, your goals and what your clinician thinks is safe.

Preparing for your procedure

• See an ophthalmologist (eye specialist) who confirms, usually with repeated corneal scans, that your keratoconus is progressing and suitable for treatment.
• Stop wearing contact lenses beforehand for the period your team advises, so the cornea and scans are accurate.
• Tell the team about any eye-surface problems, dry eye, herpes (cold sore) eye infections, or other eye conditions.
• Mention all medicines and allergies, including any reactions to eye drops.
• Arrange a lift home and time off work, as your vision will be blurred and the eye sore at first.
• Plan for help at home for a few days and stock up on any prescribed drops and simple pain relief.
• Ask whether one or both eyes are being treated and whether it will be on the same day or separately.

What happens

Cross-linking is done while you are awake, with anaesthetic drops to numb the eye; you are not put to sleep. A small clip gently holds the eyelids open.

For the common epithelium-off method, the surgeon brushes away the thin surface layer of the cornea. Riboflavin (vitamin B2) drops are then put on every few minutes for a period (often around ten minutes or more) so they soak into the cornea. A measured dose of ultraviolet light is then shone onto the eye — for several minutes in accelerated treatments, longer in the standard method.

At the end, a soft 'bandage' contact lens is placed on the eye to protect the healing surface and make it more comfortable. The procedure itself usually takes under an hour, though you should allow up to half a day at the hospital. You go home the same day with eye drops and instructions.

Is this procedure right for me?

A good consultation should explore whether it's the right choice for you now — including reasons to wait or consider something else.

Before you decide

Use this as a shared-decision checklist. The aim is not just “can this be done?”, but whether it is right for you, now, with the risks and alternatives clearly understood.

Comfort, sedation or contrast choices

If local anaesthetic, sedation, contrast or pain relief is used, ask what is planned, why, and what it means afterwards.

The biggest early issue is several days of a sore, light-sensitive eye while the surface heals; the most important serious risk is infection, which is why drops and follow-up matter. Cross-linking is not designed to sharpen your sight, and a small number of people end up with slightly less clear vision. Tell your surgeon about any past cold-sore eye infections or eye-surface disease, and ask what their own results and complication rates are.

Published figures to discuss

Outcomes and complication rates vary with the method used, corneal thickness, the stage of keratoconus and how well the surface heals. The figures below are cautious and drawn from a specialist NHS unit and reviews; your own specialist can give their results and explain how progression is measured.

These are literature figures, not a personalised prediction. Your own risks and likely benefits depend on your circumstances, your health, and how your care is carried out and followed up.

What happens afterwards

The first few days after epithelium-off cross-linking can be uncomfortable while the surface skin of the cornea grows back. Vision is blurry and fluctuates for a while, and the final picture is judged over months, not days.

• A sore, watery, light-sensitive eye for the first few days
• Blurred and fluctuating vision for days to weeks
• A feeling of grittiness or something in the eye while it heals
• Mild haze in vision that gradually clears
• Needing regular drops and a bandage lens at first

Aftercare

• Use the prescribed antibiotic and anti-inflammatory (steroid) drops exactly as directed to lower infection risk and ease healing.
• Take simple pain relief such as paracetamol for the first few days if you need it.
• Do not rub the eye, and do not remove the bandage contact lens yourself — let the team do this.
• Wear sunglasses for light sensitivity and avoid dusty or dirty environments.
• Keep water out of the eye: avoid swimming and be careful washing your hair until the surface has healed.
• Do not drive until your vision is confirmed adequate at follow-up.
• Attend all follow-up appointments, including the later scan to check the keratoconus has stabilised.

• Prescribed eye drops collected and instructions understood
• Simple pain relief (e.g. paracetamol) at home
• Sunglasses ready for light sensitivity
• A lift home and time off work arranged (often about a week)
• Help at home for the first few days
• Follow-up and scan appointments noted
• Clinic's contact number saved for any eye pain or worsening vision

Scars and how they heal

Cross-linking does not leave a skin scar, but it works on the cornea itself. A temporary haze in the cornea is common and usually fades over weeks to months. In a small number of people some lasting haze or scarring can remain and may affect vision. Following the drop routine and protecting the eye helps it heal cleanly.

⚠ Get urgent help if…

• Increasing or severe eye pain rather than steadily improving discomfort
• Worsening vision, or vision that suddenly drops
• Increasing redness, a lot of discharge or pus from the eye (possible infection — seek help urgently)
• A white spot or patch developing on the cornea
• The bandage contact lens falling out, with a painful eye
• Increasing light sensitivity with pain after the first few days
• Fever with a red, painful eye

Who to contact: your clinician, clinic or test provider first (keep their number to hand). For urgent advice when you can't reach them, call NHS 111. In an emergency, call 999.

General guidance — it doesn't replace the specific advice your specialist gives you.

Results & realistic expectations

A good result is that scans over the following months show the keratoconus has stopped progressing, and your vision and lens fitting stay stable. Most people still need glasses or contact lenses afterwards, and these may need updating as things settle over the first year.

Cross-linking cannot promise to improve your sight or undo changes already present, and it cannot guarantee the keratoconus will never progress again. Occasionally a repeat treatment is needed. Success is judged on scans over time, not on how the eye feels in the first few days.

For most people a single cross-linking treatment provides lasting stability, and keratoconus often naturally stops progressing by the mid-30s in any case. Occasionally the condition continues to change and a repeat treatment is considered. Cross-linking stabilises the cornea but does not stop the eye ageing or rule out future glasses, contact lenses or other treatments.

Related tests, treatments or support

Cross-linking is sometimes combined with treatments aimed at improving vision, such as certain laser procedures or implantable ring segments. These are specialist decisions, and it is important to separate the stabilising purpose of cross-linking from any vision-improving aim of the additional treatment. Your specialist will explain whether any combination is suitable for you.

Follow-up & long-term care

You will usually be seen within about a week to remove the bandage lens and check the surface has healed, then again as the eye settles. A repeat corneal scan is commonly arranged at around six months to confirm the keratoconus has stabilised, with a longer-term plan for monitoring and updating glasses or lenses. Report any increasing pain, discharge or worsening vision straight away.

• Attend regular eye reviews and repeat corneal scans as advised to confirm stability
• Keep up-to-date with glasses or contact lens checks as your vision settles
• Avoid rubbing your eyes, which can worsen keratoconus
• Seek prompt review if vision starts to change again
• Manage allergies and eye-surface problems that make you want to rub

Repeat, follow-on and what comes next

• Most people need only one treatment, but occasionally progression continues and repeat cross-linking is considered.
• Cross-linking stabilises the cornea but does not remove the need for glasses or contact lenses.
• Some people later need vision-improving procedures or, rarely, a corneal transplant.
• Updating glasses or lenses is common as vision settles over the first year.

Ask what happens if the result is unclear or needs repeating, and what is included if further tests or follow-up are needed.

What good aftercare looks like

• A clear drop schedule (antibiotic and anti-inflammatory) with written instructions.
• A named contact and urgent route to be seen for eye pain, discharge or worsening vision.
• Early review to remove the bandage lens and check the surface has healed.
• A planned scan at around six months to confirm the keratoconus has stabilised.
• A clear plan for updating glasses or contact lenses as vision settles.

What affects the cost

Costs vary a great deal between people and providers, and we don't publish prices. What matters is understanding what drives the cost and making sure your quote is complete. The main things that affect it:

• The ophthalmologist's (corneal specialist's) fee and experience
• The technique used (epithelium-off, accelerated or epithelium-on)
• Corneal scans and imaging before and after treatment
• Whether one or both eyes are treated, and on the same day or separately
• The bandage contact lens and the eye drops prescribed afterwards
• Follow-up appointments and the later stabilisation scan
• Facility or theatre fees

• The surgeon's fee and which technique is included
• Pre-treatment corneal scans and assessment
• Whether one or both eyes are covered, and the cost per eye
• The bandage lens, eye drops and follow-up appointments
• The later scan to confirm the keratoconus has stabilised
• What happens — and who pays — if a repeat treatment is needed
• The cancellation policy

On the NHS? Corneal cross-linking is available on the NHS for progressive keratoconus when agreed criteria are met; some people pay privately for quicker access or choice of provider, but treatment is only appropriate when scans show the keratoconus is getting worse.

You're entitled to your total cost in writing — including reports, follow-up and what happens if the result is inconclusive — before you decide.

Consent traps and marketing red flags

These are not small details. They are often where patients lose choice, time to reflect, or realistic expectations.

Choosing a specialist safely

• Check the specialist is on the GMC Specialist Register for this area.
• Make sure they work at a CQC-registered service, and look for membership of the relevant Royal College or professional body.
• You're entitled to time to consider and to have your questions answered before you agree — the specialist who looks after you should explain it, not a salesperson.
• Be wary of pressure: time-limited offers or deposits taken before you've had time to think are red flags, not bargains.
• You're entitled to your total cost in writing — including any follow-up — before you decide.

How Vuemedics verifies every consultant →

Take this to your consultation. A good specialist will welcome every one of these.

• How do you know my keratoconus is actually progressing and needs treating now?
• Which method will you use (epithelium-off, accelerated or epithelium-on) and why?
• What can I realistically expect for my vision afterwards?
• How sore will the eye be and how long until I can drive and work?
• What are your own success and complication rates?
• What happens if it doesn't stop the keratoconus progressing?
• Are you on the GMC Specialist Register for this area, and which Royal College or professional body are you a member of?
• Will you be the specialist who carries out my procedure, and who looks after me afterwards?
• What are the risks for someone like me, and how often do your own patients have a problem or need it repeated or redone?
• What does a realistic result look like — and what can this procedure not achieve?
• What are my options, including waiting, doing nothing for now, or choosing a different approach?
• Can I have written information, results and aftercare instructions in a format I can use, including any accessibility or communication support I need?
• What is the total cost in writing, including any follow-ups, and how much time do I have to decide?

Find a verified specialist for corneal cross-linking (for keratoconus)

Every consultant is GMC-checked and independently reviewed. Search by postcode and distance, or switch to a map. Ordered by rating, relevance and recency — never by who pays.

How we made this page

Medically reviewed by a GMC-registered consultant. Written in plain English, checked against NHS, NICE, GMC and relevant Royal College / specialist-society guidance, and kept under review. No clinic paid to appear on this page, and we publish no pricing. This is general information to help you prepare — it is not a substitute for advice from your own clinician. How we review our guides →

Source hierarchy: UK regulator and NHS/NICE guidance first, then relevant Royal College or specialist-society guidance, then peer-reviewed evidence for procedure-specific figures where available.

Sources & standards: Moorfields Eye Hospital — Corneal cross-linking NICE IPG466 — Photochemical corneal collagen cross-linkage for keratoconus and keratectasia NICE IPG466 — Recommendations Cambridge University Hospitals NHS — Corneal cross-linking for keratoconus Leeds Teaching Hospitals NHS — Keratoconus & corneal cross-linking Corneal collagen crosslinking in keratoconus — review (PMC)

Reviews reflect patients' experience of care, not clinical outcomes. For procedure volumes and outcome data see PHIN.

Last medically reviewed 2026-09-21. Spotted something wrong or out of date? Report an error in this guide.