Collagen cross-linking (CXL) is based on the absorption of UV-A radiation by the cornea after riboflavin, a photosensitizer, is infused in the stroma. The combination of the irradiation and the stiffening effect into the cornea leads to corneal stabilization for several years after application. However, visual performance in patients treated with CXL shows little or no improvement. That’s when the application of laser ablation was introduced, with simultaneous treatment of PRK followed by CXL.
Therefore, CXL Plus combines epithelium-off CXL with topography-guided photorefractive keratectomy (PRK) in the same session or sequentially.
The goal of simultaneous topography-guided PRK and CXL is to offer keratoconus patients corneal stability as well as functional vision. Reaching functional vision involves improving Unaided Visual Acuity and corneal irregularity so that patients are less dependent on contact lenses and/or to achieve better quality of vision. Topography-guided PRK is a predictable and effective technique to achieve remodelling of the corneal surface and rehabilitation of refractive impairment. CXL can stabilize the corrected cornea and inhibiting keratoconic progression.
PRK has been used as a treatment for the visual rehabilitation of keratoconic patients for several years. In cases of early or forme fruste keratoconus, surface ablation techniques have exceptional results, with several studies supporting the use of laser ablation to correct astigmatism in patients with early keratoconus. The ablation reshapes the corneal surface, and CXL then halts progression of the disorder. In turn crosslinking of the ablated stroma offers the advantage of depopulating keratocytes and reducing the possibility of haze formation.
Simultaneous PRK followed by CXL is a premium customised treatment capable of offering patients functional vision and halting progression of the disorder. Performing this technique with careful observation of safety aspects may offer patients with keratoconus the opportunity to gain functional vision, avoid complications of long-lasting contact lens use, and reduce the need for later keratoplasty (Corneal graft).