Abstract
Abstract: :
Purpose: Corneal scattering is assumed to be a consideral drawback of refractive surgery. At present, only subjective methods are available to estimate haze development. The purpose of this study is to get a quantitive relation between corneal scattering and the broadening of peaks in tscherning images after refractive surgery Methods: Images of the Wavelight aberrometer were analysed. They can be seen as the result of a double pass experiment in which light gets scattered twice at the corneal plane, once localised (way–in) and once non–localised (way–out). This scattering causes broadening of the incoming laser profile. These profiles were measured before refractive surgery, 1 day, 1 week and 1 month, 3 months and 6 months after surgery. In the scattering model, only anomalous scattering is taken into account due to the similar optical properties of activated myofibroblasts observed in confocal microscopy. Analysis was performed in Matlab. Results: 60 eyes following Lasik, Epi–Lasik or PRK have been examined before surgery, one day post–op, 1 week post–op one month post–op, 3 months post–op and 6 months post–op. All spots of the tscherning images have been compared and interpollated to corneal scatter maps. We observed very low scatter befory surgery, serious increased scatter 1 day until 1 week after surgery. From 1 month until 6 months scatter tends to go back to the initial value. Conclusions: In this study we correlated the peak broadening of tscherning images of eyes following refractive surgery with the increased corneal scattering. The results are appropriate according morphologic changes of the cornea after refractive sugery.
Keywords: cornea: stroma and keratocytes • optical properties • refractive surgery: optical quality