ArF 193 nm excimer laser corneal surgery as a possible risk factor in cataractogenesis

It was evaluated whether ArF 193 nm excimer laser corneal surgery represents a risk factor in cataractogenesis. For this purpose, 20 male albino rabbits underwent a photorefractive keratectomy and biochemical analyses on aqueous humour (hydrogen peroxide, ascorbic acid, and reduced and oxidized glutathione) and on lens (malondialdehyde, reduced and oxidized glutathione) were performed. In the aqueous humour of all treated animals a significant increase in hydrogen peroxide and in oxidized glutathione and a concomitant decrease in ascorbic acid and reduced glutathione concentration were observed. Moreover, all these variations were significantly correlated with the cumulative UV dose used. In the lens, after excimer laser corneal surgery, there was a dramatic loss of reduced glutathione and a parallel increase in oxidized glutathione levels. Malondialdehyde concentration was also increased, but only at the highest UV exposure. Moreover, all these variations were significantly correlated with the cumulative UV dose used. These findings demonstrate that the exposure of aqueous humour and lens to the secondary radiation generated after ArF 193 nm excimer laser corneal photoablative keratectomy induces biochemical modifications which are known to be markers of cataractogenesis.