In my clinic, patients with borderline LASIK suitability test results using cornea topography and tomography (i.e. cornea mapping) are usually carefully counselled before options presented for consideration.
The possible options, depending on the post-LASIK ectasia risk profile, are: LASIK-EXTRA, LASEK, LASEK-EXTRA and ICL (implantable contact lens).
SMILE-EXTRA had been tried out before too, although currently it is still much rarer than the other options, due to limited experience in the medical community. ICL disturbs the cornea the least amongst the various options, although it has its own set of suitability criteria such as depth of the front of eye etc.
EXTRA refers to accelerated cornea collagen cross-linking in conjunction with a refractive laser procedure, using a combination of UV-A light by the Avedro machine, and vitamin B solution.
The process of cross-linking improves the biomechanical strength of the cornea, and was initially created to treat ectasia that arise from the cornea disease called keratoconus, by Professor Theo Seiler, a Swiss/German ophthalmologist, whom I am very fortunate to have trained with.
It is also used to treat post-LASIK ectasia complication. Somewhere along the line other scientists started to offer cross-linking as a preventive treatment during LASIK.
It has been shown that LASIK-EXTRA improves cornea stability after treatment and reduces risk of power regression, with very minimal side effects. My experience with LASIK-EXTRA and LASEK EXTRA have been very positive. Many doctors offering EXTRA believe that it reduces risk of post-LASIK ectasia by around 50%.
Below is the summary of a scientific article on this:
Combined laser in-situ keratomileusis and accelerated corneal cross-linking: an update.
Abstract
PURPOSE OF REVIEW:
The purpose is to review the literature of combined laser in-situ keratomileusis (LASIK) and accelerated corneal collagen cross-linking (CXL) in context of its indications-contraindications, kerato-refractive, visual and safety outcomes, particularly with reference to preventing the development of post-LASIK ectasia.
RECENT FINDINGS:
LASIK + accelerated CXL has been developed with the rationale that the addition of CXL after LASIK may strengthen the LASIK compromised corneal biomechanics and minimize the complications such as post-LASIK ectasia. Different clinical studies have documented the safety and efficacy of LASIK + accelerated CXL for the correction of myopia or hyperopia and in the patients with low predicted residual bed thickness.
SUMMARY:
Available literature shows that refractive and keratometric outcomes of LASIK + accelerated CXL are comparable or better than LASIK alone. Less regression has been observed after LASIK + accelerated CXL compared with LASIK alone and no case of post-LASIK ectasia development has been reported among 673 eyes with the follow-up ranging from 3 months to 4.5 years. Future studies with large numbers of patients and longer postoperative follow-ups are needed to establish the efficacy of LASIK + accelerated CXL in preventing the development of post-LASIK ectasia.
I hope all that was not too much medical jargon, and feel free to contact me if you need further advice. Cheerio!
