Iontophoresis corneal cross-linking (I-CXL) is a gentler, epithelium-on version of the standard treatment that stops keratoconus getting worse. Instead of scraping off the surface layer of the cornea to let riboflavin soak in, I-CXL uses a small, painless electrical current (iontophoresis) to actively drive the riboflavin through the intact surface in just a few minutes. The cornea is then treated with UVA light, which reacts with the riboflavin to create new bonds (cross-links) that strengthen and stabilise it. Because the surface is left intact, recovery is more comfortable and quicker than epi-off cross-linking. At our partner clinics in South England, iontophoresis CXL costs from £2,200 per eye, all-inclusive.
What is iontophoresis cross-linking?
Keratoconus weakens the cornea so it thins and bulges into an irregular cone, distorting vision. Corneal cross-linking (CXL) is the only treatment proven to halt this progression — it uses riboflavin and UVA light to forge extra chemical bonds between the collagen fibres, stiffening the cornea so it stops deforming.
The challenge is getting enough riboflavin into the cornea. Traditional epi-off CXL removes the surface epithelium so the riboflavin can soak in, which works very well but leaves a raw surface that is sore for a few days. Iontophoresis CXL keeps the epithelium intact and uses a low electrical current to push the negatively charged riboflavin molecules through it — combining the comfort of an epi-on approach with efficient, even riboflavin loading before the UVA step.
Who is iontophoresis CXL for?
- Progressive keratoconus confirmed on serial corneal scans
- Younger patients whose keratoconus is changing quickly
- People who want a more comfortable, faster recovery than epi-off CXL
- Those with corneal ectasia after previous laser eye surgery (selected cases)
- Patients keen to protect their vision early and preserve future options
Cross-linking aims to stabilise the cornea, not to sharpen vision — the goal is to stop keratoconus worsening. It is often combined with, or followed by, vision-improving treatments such as corneal ring segments.
Has your keratoconus been changing? A corneal assessment with tomography confirms whether your cornea is progressing and suitable for iontophoresis cross-linking.
Book a corneal assessmentCross-linking pricing options
Your surgeon will recommend the cross-linking technique best suited to your corneal thickness and how active your keratoconus is.
Once the cornea is stable, vision can often be improved with Intacs corneal ring segments or CTAK tissue addition. For advanced disease your surgeon may discuss DALK partial-thickness transplant or Bowman layer transplant.
What happens during iontophoresis CXL
I-CXL is a day-case procedure under local anaesthetic eye drops. You stay awake and feel no pain — each eye takes around 30 minutes.
- Numbing drops are applied and your eye is gently held open.
- A small iontophoresis applicator filled with riboflavin solution is placed on the eye, and a low, painless current drives the riboflavin into the intact cornea over a few minutes.
- Riboflavin loading is confirmed and the applicator removed.
- The cornea is exposed to controlled UVA light, activating the riboflavin to form new cross-links that stiffen the tissue.
- A protective bandage contact lens is placed and you rest briefly before going home.
Recovery week-by-week
Because the surface is preserved, recovery is more comfortable than epi-off CXL. Vision stabilises gradually over the following months.
Day of treatment
Mild grittiness, watering and light sensitivity. A bandage contact lens protects the eye. Rest and start your drops; no rubbing.
Days 1–3
Comfort improves quickly with the epithelium intact — typically easier than epi-off recovery. Vision may be hazy.
Week 1–2
First review checks healing. Most return to work and screens within a few days. Vision begins to settle.
Months 1–6
The cornea stabilises. Scans confirm keratoconus has stopped progressing. Glasses or contact-lens fit can be updated.
Long term
Cross-linking is usually a one-time treatment per eye. Annual corneal monitoring confirms ongoing stability.
What's included in the price
Our iontophoresis CXL pricing is all-inclusive: consultant assessment, corneal tomography and thickness scans, the iontophoresis riboflavin delivery, the UVA cross-linking, post-op drops and your review appointments.
- Self-pay: from £2,200 per eye for iontophoresis (epi-on) CXL; from £2,500 per eye for standard epi-off CXL.
- Insurance: cross-linking is covered by many insurers where progressive keratoconus is documented — we help with authorisation.
- Finance: 0% options available to spread the cost.
Compare every keratoconus option on our prices hub and the treatments hub. If you wear specialist lenses, ask about scleral lens fitting after stabilisation.