Excimer laser surface ablation: a review of recent literature

Abstract

The aim was to review the recently published literature on excimer laser surface ablation procedures, including photorefractive keratectomy (PRK), laser sub-epithelial keratomileusis (LASEK), microkeratome-assisted PRK (epi-LASIK) and trans-epithelial (laser-assisted) PRK, to help elucidate where and how surface ablation may best fit into current refractive surgical practice. The emphasis was on publications within the last three years and included systemic reviews, meta-analyses and randomised controlled trials. Where such evidence did not exist, selective large series cohort studies, case-controlled studies and case series with follow-up preferably greater than six months were examined and included. Refractive and visual outcomes are excellent and comparable to those after LASIK even in complex cases after previous corneal surgery. Indeed, surface ablation combined with corneal collagen cross-linking may be used in selected eyes with biomechanical instability, where LASIK is contraindicated. In addition, there is evidence to suggest that there may be less induction of higher order aberrations with surface techniques. Long-term stability and safety appear to be extremely satisfactory. The literature supports the use of modern excimer laser surface treatments, with outcomes comparable to those after LASIK and evidence of less induction of higher-order aberrations. Follow-up studies at 10 to 20 years indicate excellent stability and safety.

Long Term Followup of Photorefractive Keratectomy with Adjuvant Use of Mitomycin C

“…A control group of eyes that have undergone the PRK using the same surgical technique without adjuvant MMC would have provided a means to compare the long term outcomes between PRK and PRK MMC procedures. Nevertheless, PRK outcomes presented in previous studies are comparable to our results [25]. Another limitation of the current study is that we did not examine possible changes in corneal endothelial cell density (ECD) of these patients (comparison between preoperative ECD and postoperative ECD) in order to exclude any possible MMC related toxic effects at the level on the endothelial cells.…”

To prepare the collagen‐based artificial cornea with improved mechanical and biological property by ultraviolet‐A/riboflavin crosslinking

“…After being crosslinked, the biomechanics of the collagen could be improved evidently . Meanwhile, this method has been widely used in clinic to delay or stop the process of the cornea destabilization and to treat the corneal ectatic diseases because of its good biocompatibility as well as crosslinking efficiency …”

Assessment of the influence of viscoelasticity of cornea in animal ex vivo model using air‐puff optical coherence tomography and corneal hysteresis

“…Hence, corneal thinning generates limitation of the study. Although we used a standard riboflavin‐UVA induced CXL, the treatments with other agents not causing corneal thinning could be used . Since S sec showed dependence on the IOP, S sec can be also regarded as the potential indicator of the clinically relevant eye parameter like IOP, and therefore can be considered during development of novel noncontact tonometry method.…”