Review of current indications for combined very high fluence collagen cross-linking and laser in situ keratomileusis surgery

Abstract

In this brief review we will discuss the reasoning and evolution of our current use of combined very high-fluence collagen crosslinking and laser in situ keratomileusis. Several presentations and pertinent publications are reviewed, along with the key steps of the enhanced LASIK procedure. Long term outcome data support the safety and efficacy of LASIK Xtra in stabilizing myopic but also hyperopic LASIK results. In conclusion, we have compelling evidence that LASIK Xtra is a safe and effective adjunct.

Novel myopic refractive correction with transepithelial very high-fluence collagen cross-linking applied in a customized pattern: early clinical results of a feasibility study

“…Over the years, most clinicians have referred to this process as “flattening,” which has often been interpreted as “disease regression.” We have long theorized that this flattening is a refractive effect resulting from differential cross-linking between different segments of the cornea, resulting in a dissimilar stiffening effect, which macroscopically is interpreted as a refractive change. Our group has reported previously on the use of higher-fluence collagen cross-linking as a prophylactic refractive stability modulator in both myopic and hyperopic laser-assisted in situ keratomileusis 12–14. We have also recently reported impressive refractive changes in astigmatic keratotomy when “flash” collagen cross-linking is applied just at the incision margins 15…”

Presbyopic PiXL Cross-Linking

“…Specifically, we have introduced the concept of accelerated, high-fluence collagen cross-linking in post-LASIK ectasia [32], as well as the utilization of prophylactic CXL in routine LASIK [33], and in situ, femtosecond laser-assisted treatment of corneal ectasia [34], in attempting corneal deturgescence [35] in bullous keratopathy [36] and as a prophylactic intervention adjuvant to Boston keratoprosthesis surgery [37]. The procedure known as the Athens Protocol (AP) [38] involves sequentially excimer laser epithelial debridement (50 lm), partial topography-guided excimer laser stromal ablation, and high-fluence UVA irradiation (10 mW/cm 2 ), accelerated (10 0 ) CXL.…”

Fabrication of submicron proteinaceous structures by direct laser writing

“…11,12 A similar mechanism is described for photo-initiated cross-linking of DNA and protein, 14 which is amongst others applied to cell analysis 15 and in situ surgery. 16 For proteinaceous hydrogel structures, the conservation of protein functionality post polymerization has been demonstrated by confirming biotin-avidin affinity. 17 To date, the following applications of proteinaceous structure fabrication have been employed: (i) in situ guidance 18 and capture 19 of living cells.…”