An overview of corneal collagen cross-linking (CXL).

Corneal collagen cross-linking (CXL) was first described over a decade ago and is now considered to be one of the most important surgical innovations of modern ophthalmology. Prior to its introduction, no interventions were available to arrest, or slow down ectatic disease progression, with corneal transplantation required in the majority of cases. Unlike earlier treatments of corneal ectasias that attempted to only improve the consequences of the disease, CXL aims to address the corneal biomechanical weakening itself. The long-term safety and efficacy of CXL have been established in several studies that have documented significant improvements in all outcome measures (visual acuity, spherical equivalent, astigmatism, and keratometric findings). The emerging combination of CXL with other interventions (termed 'CXL plus') optimizes the visual and topographic outcomes. This, along with the expansion of the techniques' indications for other clinical conditions, such as microbial keratitis, highlights the continuous improvement of the initial technique and confirms its wide acceptance. Overall, CXL has already demonstrated much promise and has several clinical indications, representing a clear example of recent advances in ocular therapy

One-year follow-up of corneal confocal microscopy after corneal cross-linking in patients with post laser in situ keratosmileusis ectasia and keratoconus.

To investigate corneal tissue alterations after corneal collagen cross-linking in patients with post laser in situ keratosmileusis (LASIK) keratectasia and keratoconus. Prospective comparative case series. Five patients (5 eyes) with iatrogenic keratectasia after LASIK and 5 patients (5 eyes) with progressive keratoconus were included. All eyes underwent corneal cross-linking and were assessed by corneal in vivo confocal microscopy. Three normal/healthy and 3 post-LASIK without ectasia corneas were also examined as controls. All corneas revealed normal epithelial thickness before and after surgery. Images of both keratoconic and post-LASIK corneal ectasia eyes revealed similar morphologic alterations. The subepithelial nerve plexus was absent immediately after treatment; regeneration of nerves was evident after the third postoperative month. Keratocytes were absent from the anterior 300 mum of the stroma in the first 3 months while the posterior stromal density of keratocytes was increased. Corneal collagen fibers in the anterior stroma were distributed unevenly in a net-like formation. Full-thickness keratocyte repopulation in the anterior and mid-corneal stroma was detected 6 months after treatment. The corneal endothelium did not undergo any significant changes, since the cell density and hexagonality was not found altered during the follow-up period. Keratocyte nuclei apoptosis in the anterior and intermediate corneal stroma along with collagen alterations were observed during the first 3 postcorneal cross-linking months. Gradual keratocyte repopulation was demonstrated over the following months. Corneal alterations after corneal cross-linking were similar in both keratoconic and post-LASIK corneal ectasia eyes

Photorefractive keratectomy followed by same-day corneal collagen crosslinking after intrastromal corneal ring segment implantation for pellucid marginal degeneration.

A 28-year-old man with progressive pellucid marginal degeneration (PMD) had photorefractive keratectomy (PRK) followed by same-day corneal collagen crosslinking (CXL) for progressive PMD 12 months after intrastromal corneal ring segment implantation (Intacs). No intraoperative or early postoperative complications occurred. Nine months postoperatively, the uncorrected distance visual acuity improved from finger counting to 20/63 and the corrected distance visual acuity improved from 20/40 to 20/25. Corneal topography revealed a significant improvement in keratometry (from 46.73/38.67 to 44.92/39.01), which remained stable during the 9-month follow-up period. Despite the encouraging results, longer follow-up is necessary to evaluate the outcomes of this approach

A 1-year study to compare the efficacy and safety of once-daily travoprost 0.004%/timolol 0.5% to once-daily latanoprost 0.005%/timolol 0.5% in patients with open-angle glaucoma or ocular hypertension

European Journal of Ophthalmology172183-190EJOO