Corneal Cross Linking (CXL)
This crosslinking reaction
Description
Corneal Collagen Cross-Linking (CXL) is an exciting new corneal surgical procedure that is currently approved for use abroad and is undergoing clinical trials in the United States for FDA approval. CXL and bonding technology has been used in dentistry, orthopedics, and dermatology for many years. Its potential benefit in ophthalmology is to improve the biomechanics of the cornea. CXL is used to help stiffen weak corneas that are progressively warping, such as those that suffer from the corneal disease keratoconus. CXL is a simple, safe, and effective procedure for the management of ectatic, inflammatory diseases of the cornea as well as corneal melting and bullous keratopathy. In the near future, CXL treatments may become a standard of care.
CXL results abroad confirm the procedures’ effectiveness in stabilizing corneal biomechanics and rehabilitating patients without the need for more invasive procedures.
In CXL, the cornea is soaked with a vitamin solution and then exposed to ultraviolet light. This process creates new cross-links between the fibers of the cornea, increasing its strength and helping to prevent further corneal warping from occurring.
Treatment
It is important to realize that the goal of treatment is not a refractive endpoint—even if CXL is combined with laser vision correction surgery, such as PRK. The main purpose of the treatment is to limit further progression, as well as improve and stabilize the shape of the cornea to provide better functional vision. Spectacles and/or contact lenses (hard or soft) will usually still be required.
The best news is that this minimally invasive procedure has very few risks and avoids the disruption that comes with corneal transplantation. With CXL, patients can continue their lifestyles and jobs with useful vision.
Risks or Complications
Risks of CXL include but are not limited to:
- Corneal haze, which is uncommon and easily managed with topical steroids
- delay in corneal surface cell healing
- infection
- corneal-inflammatory infiltrates
- potential for reactivation of herpes simplex virus and dendritic ulcer
- ocular surface disorder and tear dysfunction
Post-operative Management
After treatment, an antibiotic ointment and a bandage contact lens soaked with preservative-free antibiotic are applied until healing of the corneal epithelium is complete. The bandage contact lens is applied for 5 days to help with corneal surface cell healing. Afterward, the patient is typically instructed to apply steroid eye drops for 6 to 8 weeks. A slight corneal surface haze, comparable with the healing reaction following corneal abrasion in PRK, can be seen in the first 6 to 8 weeks following surgery. Postoperative follow-up is performed frequently in the first week until the corneal surface cells are completely healed; and usually at 1, 3, 6, and 12 months postoperatively; and yearly thereafter.
Individual tolerance to pain and light sensitivity is highly variable. Patients should take this into account and plan for the possibility of analgesics and sedation after surgery, and account for days off work.
