The potential problem lies elsewhere. This procedure involves a laser beam at 193 nm that practically evaporates part of the cornea, breaking cells and molecules to create the smooth surface necessary for the best optical results. The creation of free radicals, therefore, is an inseparable part of the corneal-reshaping process. These procedures are also known to cause biochemical and ultrastructural modifications in the lens, both of which are markers of cataractogenesis. Because the vitreous base is located immediately behind the lens, there is every reason to expect that it will be affected by the same process that affects the cornea, the anterior chamber, and the lens.
Free radicals damage the vitreous collagen with consequential vitreous liquefaction.
They have also been demonstrated to promote tumors. The vitreous base is associated with severe retinal complications, such as retinal tears, retinal detachment, epiretinal membrane, and macular holes. The question that needs to be addressed, therefore, is whether this photoablative process causes any shift in the natural deterioration of the eye as a complete organ, undivided artificially into anterior and posterior segments. Otherwise, these risks will remain theoretical until data accumulated over time will reveal whether we have opened a Pandora's box. Until our knowledge on this issue is refined, patients currently undergoing the procedure must be informed that animal studies have shown tissue changes suggesting possible long-term damage of an unknown nature to the cornea, and that early development of cataract might also result from the treatment.