Corneal Crosslinking (CXL): The procedure that halts keratoconus progression – protocols, procedure, price
Warsaw · Krakow · Vienna · Zurich
Crosslinking (corneal collagen crosslinking, CXL) is the only method that halts the progression of keratoconus instead of merely correcting its effects. The cornea is saturated with riboflavin and irradiated with a controlled dose of UVA, which creates new bonds between collagen fibers and stiffens the tissue. At SwissLaser, we have been performing CXL since 2007, using standard, accelerated, sub400 protocols for thin corneas, and in combination with laser. Warsaw and Krakow, PLN 3,600 per eye.
Crosslinking at a glance
- Goal: to halt the progression of keratoconus (also post-LASIK ectasia). Efficacy in long-term studies: 90–98% of eyes without further progression after 10 years. CXL does not improve visual acuity; this is the task of subsequent stages.
- For whom: documented progression (Kmax +1 D per year, corneal thinning), typically aged 10–40 years, cornea from 400 µm; thinner corneas are treated with the sub400 protocol with an individualized UVA dose.
- Procedure: approximately 60 minutes per eye, topical anesthesia, epithelial debridement (epi-off), 10–30 minutes of riboflavin saturation, 10–30 minutes of UVA irradiation, bandage contact lens. No hospitalization.
- Price: PLN 3,600 per eye with two follow-up appointments in the first month; variant with laser (Cretan, Athenian, or Total Corneal Wavefront protocol) PLN 8,700. Qualification with tomography PLN 400. Price list and installments.
- Recovery: 3–5 days of discomfort during epithelial healing, office work after 5–7 days, sports after 2–4 weeks. The cornea stiffens over subsequent months; the effect is assessed tomographically after 6 and 12 months.
SwissLaser in numbers: crosslinking since 2007, method learned from Prof. Theo Seiler in Zurich · over 25,000 refractive procedures by the chief surgeon · MS-39 and Anterion tomography · one team in Warsaw, Krakow, Vienna, and Zurich · Google: 4,8 (Warsaw) and 5,0 (Krakow)
Crosslinking — Quick Answers
- Is crosslinking effective? Yes, it is the best-documented method in keratoconus treatment: 90–98% of eyes show no progression after 5–10 years. In 2–5% of patients, mainly very young ones, the procedure needs to be repeated. Efficacy is assessed by tomography after 6 and 12 months.
- Does crosslinking hurt? The procedure itself is painless thanks to anesthetic drops; you will feel touch and light. The first 2–3 days of epithelial healing are difficult: burning, tearing, and photophobia, which are alleviated with painkillers and a bandage contact lens. From day 4–5.
- How long does the crosslinking procedure take? Approximately 60 minutes per eye for the standard protocol (30 minutes saturation and 30 minutes irradiation), approximately 45 minutes for the accelerated protocol, and approximately 75 minutes for variants with laser. You spend a total of 2–3 hours at the clinic.
- When can I return to work and sports after crosslinking? Office and computer work after 5–7 days, physical work in dusty environments after 2 weeks, non-contact sports after 2 weeks, swimming pool, sauna, and contact sports after 4 weeks.
- Is crosslinking reimbursed by the NFZ (National Health Fund)? Yes, since September 2023, in selected hospitals, usually with the standard epi-off protocol and with waiting times ranging from several weeks to several months. At SwissLaser, the procedure is private (PLN 3,600), without a waiting list, and includes sub400 and laser protocols.
What is corneal crosslinking?
The cornea owes its stiffness to cross-links between collagen fibers. In keratoconus, there are too few of these bonds, so the tissue yields to intraocular pressure and bulges. Crosslinking adds bonds: riboflavin (vitamin B2) saturates the corneal stroma, and UVA light at 365 nm activates it, releasing singlet oxygen, which links adjacent collagen fibers. The cornea becomes about 300% stiffer, and the aging process, which naturally stiffens the cornea after the age of 40, is, in a way, accelerated.
The method was developed in Dresden and Zurich by Prof. Theo Seiler, Eberhard Spoerl, and Gregor Wollensak; the first procedures were performed in 1998, the method received CE certification in 2007, and the American FDA approved it in 2016. Dr. Derhartunian learned crosslinking directly from Prof. Seiler at the IROC clinic in Zurich and has been performing it since 2007.
What crosslinking does and does not do
- Halts the disease: in 10-year studies (Raiskup and Seiler, Dresden), progression ceased in over 90% of eyes; in some, the cornea flattened by 1–2 D.
- Does not intentionally improve visual acuity. The distortion that has already occurred remains; we correct it later with lenses, laser, CAIRS, or ICL.
- Does not replace lenses: after the procedure, you return to glasses or contact lenses, usually with the same or slightly lower prescription.
- Protects against transplant: since the widespread adoption of CXL, the number of corneal transplants due to keratoconus has decreased by more than half in Europe.
Video: What is keratoconus treatment with crosslinking?
A short video from the SwissLaser channel: how collagen crosslinking works and why it halts the disease.
When is crosslinking indicated, and when is it better to wait?
Progression is the indication, not merely the diagnosis. According to the international consensus (Global Consensus on Keratoconus, 2015), progression is evidenced by a change in at least two of three parameters between tomographic examinations:
- steepening of the anterior corneal surface: Kmax by more than 1 D within 12 months
- steepening of the posterior corneal surface or increase in ABCD scale indices
- thinning of the thinnest corneal point by more than 5% or increasing refractive error
| Situation | Our approach |
|---|---|
| Teenager or young adult with diagnosed keratoconus | with clear progression or very steep cornea: CXL without delay; with uncertain results: second tomography after 3 months |
| Adult 30–40 years old, stable keratoconus in two examinations | observation every 6–12 months; focus on vision correction |
| Cornea thinner than 400 µm after epithelial debridement | sub400 protocol with individually calculated UVA dose (according to Hafezi) or hypoosmolar riboflavin; we do not automatically refuse |
| Ectasia after LASIK or PRK | CXL as for keratoconus, usually with accelerated protocol |
| Pregnancy, breastfeeding, active eye inflammation | procedure postponed; tomographic control every 3 months |
| Central scars, thickness below 300 µm | CXL is not effective; we discuss CAIRS or transplant |
Crosslinking protocols we use
There is no single crosslinking. The dose, time, and method of riboflavin administration are chosen based on corneal thickness, age, and tomographic map. All variants are performed in Warsaw and Krakow.
| Protocol | What it involves | For whom | Time | Price per eye |
|---|---|---|---|---|
| Epi-off standard (Dresden) | epithelial debridement, riboflavin 30 min, UVA 3 mW/cm² for 30 min | most patients; longest studied protocol (10-year data) | approx. 70 min | PLN 3,600 |
| Epi-off accelerated | same energy dose (5.4 J/cm²) at higher intensity: 9 mW/cm² for 10 min | young patients, post-LASIK ectasia, lower tolerance for long procedure | approx. 45 min | PLN 3,600 |
| Sub400 (individual dose) | irradiation time calculated from corneal thickness after saturation to protect endothelium | corneas thinner than 400 µm, advanced keratoconus | approx. 60 min | PLN 3,600 |
| Epi-on (transepithelial) | epithelium remains; riboflavin with penetration enhancers, higher UVA dose | exceptionally: intolerance to epithelial healing, very thin epithelium; lower efficacy | approx. 60 min | PLN 3,600 |
| Cretan protocol: CXL + PTK | epithelium removed by excimer laser transepithelially, deeper over the cone apex, then CXL | irregular cornea without sufficient thickness for refractive ablation | approx. 75 min | PLN 8,700 |
| Athenian protocol: CXL + topographic PRK | laser smooths the cornea according to a topographic map (up to 50 µm) and partially corrects the defect, CXL stabilizes the effect | cornea with sufficient thickness, dominant irregular astigmatism | approx. 75 min | PLN 8,700 |
| CXL + Trans-PRK Total Corneal Wavefront | ablation plan from a three-dimensional model of both corneal surfaces (MS-39 2nd gen.), then CXL | complex aberrations of the entire cornea, not just its shape | approx. 75 min | PLN 8,700 |
All laser variants halt the disease just as effectively as CXL alone; they differ in how much visual quality can be recovered incidentally. The Schwind Amaris 1050RS laser removes a maximum of 50 µm of tissue, ensuring the cornea retains a safe thickness after the procedure. The term “Athenian protocol” comes from Prof. Kanellopoulos’s team in Athens, and “Cretan” from Prof. Kymionis in Heraklion.
Video: crosslinking combined with laser
Dr. Victor Derhartunian on combining crosslinking with laser corneal regularization: halting the disease and improving visual quality in one procedure.
How the Crosslinking Procedure Works Step-by-Step
Qualification
MS-39 tomography with epithelial map, Anterion, pachymetry, endothelial evaluation. Comparison with previous examinations determines progression and protocol. Approximately 90 minutes, PLN 400. Discontinue contact lenses: soft 7 days, hard 3–4 weeks prior.
Day of Procedure
Topical anesthesia, disinfection, eyelid speculum. Gentle epithelial debridement in the 8–9 mm zone (or by laser in the Cretan protocol), riboflavin saturation for 10–30 minutes with thickness control, UVA irradiation for 10–30 minutes using the C-EYE system with dose control. Total approximately one hour per eye, pain-free.
First Days
Bandage contact lens until epithelium heals (3–5 days), antibiotic and anti-inflammatory drops, painkillers. Days 1–3 can be unpleasant: burning, tearing, and photophobia, which are alleviated by prescribed medications and a bandage contact lens. From day 4–5.
Follow-up and Effect
Follow-up after one month (both included in price), tomography after 6 and 12 months, then annually. For the first 1–3 months, vision may be worse than before the procedure (transient haze), then it returns to baseline or improves. The second eye, if required, is usually operated on after 1–4 weeks.
Recovery Day by Day
- Day 0: after the procedure, rest at home, dark glasses, drops according to schedule. Do not rub the eye.
- Days 1–3: the most difficult period, epithelial healing; pain is alleviated by prescribed medications, cold compresses, and sleep. We issue sick leave for this period.
- Days 4–7: bandage contact lens removal, return to office work and screen use, driving after doctor’s approval.
- Weeks 2–4: non-contact sports, eye makeup from week 2, swimming pool and sauna after 4 weeks. Contact lenses after 4–6 weeks, new glasses after 3 months.
- Months 1–12: the cornea gradually stiffens and slightly flattens. Moisturizing drops for several months; UV protection (glasses with filter).
Crosslinking Results and Safety: Numbers, Not Promises
- Efficacy: progression halted in 90–98% of eyes in 5–10-year observations (e.g., Raiskup et al. 2015, Dresden; Wittig-Silva 2014, Melbourne). Re-crosslinking is needed in 2–5% of patients, most often teenagers.
- Corneal flattening: average of 1–2 D Kmax within 1–2 years; in some patients, improvement of best corrected visual acuity by 1–2 lines, in most without change.
- Transient haze: in about 10% of eyes, resolves in 3–12 months; persistent haze below 2%.
- Delayed epithelial healing, sterile infiltrates: 1–3%, treated with drops.
- Corneal infection: below 1%; prevented with antibiotics and bandage contact lens control. This is the most important reason not to rub the eye and to use drops according to schedule.
- Endothelial damage: risk applies to corneas thinner than 400 µm with a standard dose; this is why we use sub400 and measure thickness during the procedure.
Patients ask if the procedure hurts. The procedure itself does not, but the first three days can be difficult. They also ask if they will see better. I answer honestly: we perform crosslinking so that in ten years there will be no need for a transplant. It is a procedure that provides stability, not an immediate effect. Vision improvement is planned separately, once the cornea is stable.
Dr. med. Victor Derhartunian, FEBO, FWCRS
Am I eligible for crosslinking?
Green light
- documented keratoconus progression (Kmax +1 D per year, thinning, ABCD increase)
- age 10–40 years; in older patients with confirmed progression
- corneal thickness from 400 µm after epithelial debridement (thinner: sub400)
- corneal ectasia after laser vision correction
- transparent cornea without central scars
Yellow light
- stable keratoconus without progression: observation every 6–12 months
- severe dry eye syndrome or acute allergy: first, treatment of the ocular surface
- very thin cornea 300–400 µm: sub400 or hypoosmolar riboflavin after endothelial evaluation
- previous hydrops: procedure after edema subsides and scar is evaluated
Red light
- corneal thickness below 300 µm or dense central scars: consider CAIRS or transplant
- active infection or eye inflammation
- pregnancy and breastfeeding: procedure after breastfeeding ends
- active autoimmune diseases and healing disorders
Don’t have tomography yet? Start with online preliminary qualification or schedule an examination in Warsaw or Krakow. If you have corneal maps from another center, attach them; comparing them speeds up the decision.
Sign up for a no-obligation visit and consultation to learn how we can improve your vision.
How much does crosslinking cost and what is included
- Crosslinking (any epi-off, accelerated, sub400, epi-on protocol): PLN 3,600 per eye.
- Crosslinking with laser (Cretan, Athenian, Total Corneal Wavefront): PLN 8,700 per eye.
- Included in the price: procedure, riboflavin, bandage contact lens, follow-up the next day and after one month, sick leave.
- Not included in the price: qualification with tomography PLN 400, post-procedure drops (approx. PLN 100–150 at the pharmacy), follow-up tomographies after 6 and 12 months at the price of a control visit.
- Installments: Santander Consumer Bank, decision at the clinic or online.
Crosslinking has been covered by the NFZ (National Health Fund) since September 2023. Waiting lists and protocols vary in different hospitals; for confirmed progression in a young person, waiting several months means a real loss of tissue and vision. If you decide on NFZ, we will ask for tomography results and help assess how much time you safely have available. Laser variants, sub400 protocol, and CAIRS are not funded by the NFZ.
Frequently Asked Questions
Will I see better after crosslinking?
This is not the goal of the procedure. Some patients notice a slight improvement after corneal flattening by 1–2 D, but for the first 1–3 months, vision may be worse. If you are interested in improving visual acuity, we consider a laser variant (PLN 8,700), and after corneal stabilization, an ICL lens or CAIRS.
Epi-off or epi-on: which crosslinking is better?
Epi-off (with epithelial debridement) has the best-proven efficacy and is our standard. Epi-on is more comfortable for healing, but riboflavin penetrates the epithelium less effectively, and the rate of disease arrest is lower. We use it only in exceptional situations after discussing its limitations.
Is my cornea too thin for crosslinking?
The standard protocol requires 400 µm after epithelial debridement. Thinner corneas (even 300–350 µm) are treated with the sub400 protocol: the irradiation time is calculated individually from the corneal thickness after saturation to prevent energy from reaching the endothelium. Tomography and pachymetry results are decisive.
Can crosslinking be repeated?
Yes. If tomography after 12 months or later shows further progression, the procedure is repeated, usually with the accelerated protocol. This applies to 2–5% of patients, most often teenagers with aggressive keratoconus.
Is crosslinking performed on both eyes simultaneously?
Usually not. We operate on one eye, and the second after 1–4 weeks, when the first has healed enough to function. If keratoconus affects only one eye or the other is stable, the procedure is performed only where there is progression.
Can laser vision correction be performed after crosslinking?
Classic LASIK remains contraindicated. However, laser corneal regularization combined with CXL (Athenian or Cretan protocol) is possible, and after a year of stability, full correction of the refractive error with an ICL lens, which does not interfere with the cornea.
How long does the effect of crosslinking last?
10-year data show stable stabilization in the vast majority of patients. The cornea also naturally stiffens after the age of 40. However, we recommend annual control tomography, as rare late progressions are only detected by examination.
Sign up for a no-obligation visit and consultation to learn how we can improve your vision.
For the curious: Corneal crosslinking (CXL, collagen crosslinking) is procedure 11.74 (other corneal procedures, crosslinking) in ICD-9-PL; ICD-10 indication: H18.6 keratoconus, H18.7 corneal ectasia. Standard protocol (Dresden, Wollensak 2003): riboflavin 0.1% for 30 minutes, UVA 370 nm, 3 mW/cm² for 30 minutes, dose 5.4 J/cm²; accelerated protocols deliver the same dose in a shorter time (Kobashi 2020).
Sources
- Wollensak G, Spoerl E, Seiler T. Riboflavin/ultraviolet-A-induced collagen crosslinking for the treatment of keratoconus. Am J Ophthalmol 2003;135(5):620–627. doi:10.1016/S0002-9394(02)02220-1
- Raiskup F, Theuring A, Pillunat LE, Spoerl E. Corneal collagen crosslinking with riboflavin and ultraviolet-A light in progressive keratoconus: ten-year results. J Cataract Refract Surg 2015;41(1):41–46. doi:10.1016/j.jcrs.2014.09.033
- Koller T, Mrochen M, Seiler T. Complication and failure rates after corneal crosslinking. J Cataract Refract Surg 2009;35(8):1358–1362. doi:10.1016/j.jcrs.2009.03.035
- Kobashi H, Tsubota K. Accelerated versus standard corneal cross-linking for progressive keratoconus: a meta-analysis of randomized controlled trials. Cornea 2020;39(2):172–180. doi:10.1097/ICO.0000000000002092
- McAnena L, Doyle F, O’Keefe M. Cross-linking in children with keratoconus: a systematic review and meta-analysis. Acta Ophthalmol 2017;95(3):229–239. doi:10.1111/aos.13224
- Gomes JAP, Tan D, Rapuano CJ et al. Global consensus on keratoconus and ectatic diseases. Cornea 2015;34(4):359–369. doi:10.1097/ICO.0000000000000408
- Regulation of the Minister of Health on guaranteed benefits in hospital treatment – corneal cross-linking (cross-linking) in the NFZ basket from 2023. gov.pl/web/zdrowie
Related topics
- Keratoconus: symptoms, diagnosis, treatment ladder
- CAIRS rings for advanced keratoconus
- Keratoconus treatment price list
- ICL lenses after keratoconus stabilization
- Crosslinking: how collagen crosslinking works
- Qualification for keratoconus procedure
- Crosslinking in Warsaw
- Crosslinking in Krakow
Content medically verified by Dr. med. univ. (Vienna) Victor Derhartunian, FEBO, FWCRS, a surgeon performing crosslinking since 2007. Last updated: October 2, 2026.
Where We Perform This Procedure
We perform the procedure in both our clinics – same surgeon, same technology, and same prices. Choose a location to see details, directions, and office hours:
Keratoconus treatment in Warsaw
ul. Kolejowa 1, 01-217 Warsaw · tel. +48 22 120 16 90
Keratoconus treatment in Krakow
ul. Kluczborska 15/U3, 31-271 Krakow · tel. +48 12 383 33 60
