Corneal Crosslinking: What to Expect Before, During, and After the Procedure

Corneal crosslinking (CXL) is the only treatment proven to halt the progression of keratoconus. It works by using ultraviolet A light and riboflavin (vitamin B2) to create new chemical bonds between collagen fibrils in the corneal stroma, stiffening the tissue and preventing further ectatic change. The procedure is performed using an epithelium-off technique in which the corneal surface is removed before riboflavin is applied, similar to PRK: what to expect. This means the recovery experience, including the postoperative discomfort and healing timeline, is comparable to PRK. This guide explains what patients can expect at every stage of the crosslinking process.

Before the procedure: preparation

The preparation for corneal crosslinking is similar to that for other corneal procedures. Contact lenses should be removed in advance. Rigid gas permeable lenses require at least two to three weeks out before topographic assessment so the corneal shape returns to its natural state. Soft lenses should be removed at least one week before the procedure.

No eye makeup or skincare products around the eyes on the day of the procedure. Arrange transport home as you will not be able to drive. Eat a light meal beforehand.

Unlike laser refractive surgery, corneal crosslinking does not require a dedicated laser surgical centre. It is performed in a clean clinical or minor procedures room with appropriate UV lamp equipment. You will be awake throughout under topical anaesthetic drops.

What happens during the procedure

On arrival, antibiotic eye drops are instilled as part of infection prevention. The skin around the eyes is cleaned with antiseptic solution. Topical anaesthetic drops are applied to completely numb the eye. No injection is required. You will be awake and asked to look up at the UV lamp during the procedure.

The corneal epithelium is removed from the central 9mm zone. This is performed using a blunt spatula after the application of dilute alcohol solution to loosen the surface cells, in the same manner as PRK. The epithelial removal takes approximately 30 seconds and is painless under the anaesthetic.

Riboflavin 0.1 percent solution is applied to the cornea every two to three minutes during a soaking period of approximately 10 minutes. The riboflavin solution appears yellow and the eye will look yellow during this phase. The riboflavin must penetrate adequately into the corneal stroma before the UV light is applied.

Ultraviolet A light is then applied to the cornea using a UV lamp positioned above the eye. For accelerated crosslinking using a 9 mW/cm2 protocol, the UV exposure lasts 10 minutes. Riboflavin drops continue to be applied during the UV phase. You will be asked to look at the UV lamp steadily during this phase. Most patients describe this as a mild visual glow rather than bright discomfort.

At the completion of the UV exposure, a bandage contact lens is placed on the eye. This remains in place for three to five days while the epithelium regenerates.

Pain management after crosslinking

The postoperative discomfort after corneal crosslinking is similar to that after PRK and arises from the same cause: the corneal epithelium has been removed, leaving the richly innervated stromal surface exposed until healing is complete.

Most patients describe a burning, stinging, gritty, or foreign body sensation in the first 48 to 72 hours. The discomfort peaks in the first 24 to 48 hours and diminishes significantly once the epithelium closes at day four to five.

Ice packs applied gently to the closed eyelid provide meaningful pain relief in the first 24 to 48 hours. The cold reduces inflammation and provides direct analgesic effect. Apply a clean ice pack wrapped in a thin cloth for 10 to 15 minutes at a time, several times per hour in the first day. Do not press firmly on the eye or apply ice directly to the eye surface.

Oral analgesia with paracetamol or ibuprofen taken regularly on a scheduled basis in the first 48 to 72 hours maintains consistent comfort. Do not wait for pain to become severe before taking oral analgesia.

Cold preservative-free lubricating drops provide additional surface relief. Refrigerating the lubricating drops before use enhances their comfort effect through the temperature difference.

Prescription-strength non-steroidal anti-inflammatory drops may be provided for the first few days. Use these as prescribed.

Dim lighting and limiting screen use in the first 24 to 48 hours reduces visual fatigue and discomfort. Rest with eyes closed when possible during the first day.

Postoperative eye drops after crosslinking

The postoperative drop regimen for corneal crosslinking addresses three priorities: preventing infection during epithelial healing, reducing inflammation to promote healing, and lubricating the ocular surface.

Antibiotic drops are used four times daily for at least five days until the epithelium has healed and the bandage contact lens has been removed. The exposed stromal surface is vulnerable to infection while the epithelium is absent. Do not skip antibiotic doses during this period.

Steroid drops are used in a tapering course beginning after the epithelium has healed, typically from day five, and continuing for three to four weeks. The steroid reduces the inflammatory response in the healing stroma. Some surgeons use a more prolonged taper particularly where there is evidence of corneal haze at follow-up visits.

Lubricating drops without preservatives are used frequently throughout the day for at least three months. Crosslinking, like PRK, produces a temporary reduction in corneal sensitivity and tear function. Frequent lubrication supports surface healing and comfort.

Vision recovery timeline after crosslinking

Vision recovery after crosslinking follows a similar pattern to PRK but with some important additional considerations specific to the crosslinking response.

Days one to five: vision is blurred and uncomfortable while the epithelium is absent. Functional vision is not expected during this phase.

Week one to two: the epithelium closes and the bandage lens is removed. Vision begins to improve but may remain blurred and variable. Many patients notice their vision is temporarily worse than before the procedure during this phase. This is normal and expected.

One to three months: vision typically returns to approximately pre-procedure levels. A period of corneal oedema following the crosslinking treatment affects vision during this phase. Corneal densitometry studies confirm that corneal transparency increases after initial post-crosslinking swelling resolves over approximately 12 months.

Three to twelve months: vision stabilises and may improve beyond pre-procedure levels as the corneal surface settles and the corneal oedema resolves. A proportion of patients experience modest improvements in best-corrected visual acuity after crosslinking.

It is important to understand that crosslinking is not a procedure that improves vision. Its goal is to halt progression and preserve existing vision. Any improvement in vision is a secondary and unpredictable benefit. Patients who expect improved vision after crosslinking will be disappointed during the recovery period when vision is temporarily reduced.

Time off work and activity restrictions

Work: most patients require at least one week off from office-based work. The first week involves significant visual disability and discomfort.

Driving: not permitted until vision meets the legal standard in the operated eye. For most crosslinking patients this occurs between one and four weeks postoperatively.

Exercise: light walking from approximately day five once the epithelium has closed. Contact sports and swimming should be avoided for at least four weeks. Outdoor activities require UV-blocking sunglasses from day one for at least six months postoperatively.

Swimming: avoid pools, ocean, and spas for at least four weeks due to infection risk during the epithelial healing phase.

Risks of corneal crosslinking

Corneal crosslinking is a safe procedure with a well-established evidence base. The main risks are:

Postoperative pain: the epithelial healing phase is associated with significant discomfort in the first 48 to 72 hours. This is managed as described above and resolves with epithelial healing.

Corneal haze: a transient increase in corneal opacity is normal after crosslinking as part of the healing response. Early haze at one month is expected and typically resolves by 12 months. Persistent corneal haze causing visual impairment is uncommon. In cases of significant late haze, extended steroid treatment or topical losartan may be considered.

Infection: infectious keratitis after crosslinking is rare but has been reported in published case series. Antibiotic drop compliance during the epithelial healing phase is essential. Symptoms of infection requiring urgent assessment include increasing pain, redness, and blurred vision.

Treatment failure: crosslinking halts progression in approximately 95 percent of treated eyes. A small proportion of patients continue to show progression despite treatment, requiring repeat crosslinking or progression to surgical management.

Sterile infiltrates: small white corneal deposits can appear in the first week after crosslinking as part of the inflammatory response. These are usually asymptomatic and resolve without treatment, but should be assessed by your surgeon at the scheduled review.

When to seek urgent review: increasing pain, sudden vision loss, purulent discharge, or a visible white spot on the cornea in the postoperative period requires same-day contact with your surgeon.

For the evidence base behind crosslinking and how it fits within the broader management of keratoconus, see the detailed guide to corneal crosslinking for keratoconus. For patients considering laser refractive procedures, see the guides to LASIK: what to expect and PRK: what to expect.

References

1. 1.van der Valk Bouman ES, et al. Pain Mechanisms and Management in Corneal Cross-Linking: A Review. BMJ Open Ophthalmol. 2021;6(1):e000878.
2. 2.Managing Cross-linking Complications. Review of Ophthalmology. November 2024.
3. 3.Post-operative Management of Corneal Crosslinking Patients. EyeWorld.
4. 4.American Academy of Ophthalmology. Corneal Cross-Linking. Updated November 2023.