TREATMENT OF KERATOCONUS, DOUBTS ABOUT THE MECH- ANISM OF ACTION AND IMPEDIMENTS TO DISCUSSION

In an experimental study on keratoconus (G. Wollensak et al., “Stress- strain measurements of human and porcine corneas after riboflavin- ultraviolet-A-induced cross-linking”, J Cataract Refract Surg 29 (2003) 1780-1785), the authors observed that when strips of corneal tissue were stretched at constant elongation velocity, they responded with strain that increased according to an exponential fitting curve. This behaviour was qualified as "the typical exponential increase of a bio- viscoelastic solid". This claim is wrong and misleading, because typ- ical viscoelastic behaviour is asymptotic, not exponential, as we have already pointed out (A. Albanese et al., "Keratoconus, cross-link-in- duction, comparison between fitting exponential function and a fitting equation obtained by a mathematical model", Biomedicine & Pharma- cotherapy 63 (2009) 693-696). Other doubts are raised by the unjus- tified choice of fitting function, the surprising agreement of the experimental points with the curve (in contrast to the wide margins of error indicated) and finally the original criterion used for data pro- cessing. The fact that treatment is clearly effective does not prove that the mechanism of action is the one described in the above paper. We therefore consider it advisable to conduct further research into the real biomechanical properties of corneal tissue, because erroneous inter- pretation could make it more difficult to develop and direct therapies. This summarizes the contents of a paper that we submitted to the jour- nal in November 2009, but which fails to be accepted on the pretext of formal minutiae. We believe that in specialist journals scientific dis- putes should be solved by an exchange of arguments. Shilly-shallying to deny space for critical observations does not favour the advance of science.