Non-invasive laser used to correct myopia

Professor Sinisa Vukelic used the ftosecond oscillator – an ultrafast laser that delivers pulses of very low energy at high repetition rate – to selectively alter the biochical and biomechanical properties of collagenous tissue without causing cellular damage and tissue disruption.Vukelic’s technique apparently utilises just enough power to induce a low-density plasma within the set focal volume, but doesn’t convey enough energy to cause damage to the tissue within the treatment region.“We’ve seen low-density plasma in multi-photo imaging where it’s been considered an undesired side-effect. We were able to transform this side-effect into a viable treatment for enhancing the mechanical properties of collagenous tissues,” Vukelic said.The induction of low-density plasma causes ionisation of water molecules within the cornea, which creates a reactive oxygen species – a type of unstable molecule that contains oxygen and easily reacts with other molecules.This, in turn, interacts with the collagen fibrils to form chical bonds, or crosslinks, which when selectively introduced induce changes in the mechanical properties of the treated corneal tissue.According to Vukelic, the crosslinking alters the collagen properties in the treated regions, which results in changes in the cornea’s macrostructure.Since the process is photochical, it is said to avoid disrupting tissue and the induced changes rain stable.“If we carefully tailor these changes, we can adjust the corneal curvature and thus change the refractive power of the eye. This is a fundamental departure from the mainstream ultrafast laser treatment that is currently applied in both research and clinical settings and relies on the optical breakdown of the target materials and subsequent cavitation bubble formation,” Vukelic said.Vukelic and his team are developing a prototype for use in clinical trials before the end of the year.