EEBA Program (PDF/3MB) - EEBA - Annual Meeting

STUDY OF STROMAL FEMTOSECOND LASER ABLATION FOR DEEP CORNEAL CUTOPTIMIZATIONA. Bernard¹, C. Mauclair², E. Audouard², G. Thuret¹, M. Peoc’h¹, J. M. Dumollard¹, J. Granier³, H. Soder³, P. Gain¹¹Corneal Graft Biology, Engineering and Imaging Laboratory, EA2521, Federative Institute of Research in Sciences andHealth Engineering, Faculty of Medicine, Jean Monnet University; ²Laboratoire Hubert Curien; ³IMPULSION SAS, PôleOptique Vision, FrancePurpose: Anterior and posterior stroma of human cornea present different biophysical characteristics,the later being more hydrated and collagen fibers less tightly packed. Our aim was to investigateinteractions between femtosecond laser (FL) and stroma according to the depth of cut in order tooptimize FL endothelial graft preparation.Methods: Organ cultured human corneas were prepared with a mechanical microkeratome (Moria,France) by a lamellar cut from anterior side at two different depths: 50µm for the study of anteriorstroma and 350µm for the study of posterior stroma. Grooves were then performed in the remaininganterior or posterior stroma with a 800nm, 150fs FL (Thales, France) with different processingconfigurations (Speed: 1900 to 10000µm/s; Power: 0.8 to 6mW). After treatment, corneas wereobserved by light and second harmonic generation (SHG) microscopy to compare ablation rates (AR)(in µm/pulse) and cut quality in anterior and posterior stroma.Results: Preliminary results (n=4 corneas) showed no significant differences between posterior stromaAR (1.97±0.91µm/pulse) and anterior stroma AR (1.73±0.50µm/pulse). Using SHG microscopy, twodifferent cutting types (with or without disruption) occurred, depending on processing configurationsand independently of depth in the stroma.Conclusions: These results suggest that there is no significant difference of AR between anterior andposterior stroma. Consequently, difficulties usually encountered to cut endothelial grafts with FL maynot directly depend on a particular ablation rate of the posterior human corneal stroma, but rather onthe optical scattering when FL passes through the stromal layers, already identify as a limiting factor.XXV ANNUAL MEETING OF THE EUROPEAN EYE BANK ASSOCIATION Zagreb, Croatia 18/19 January 2013 39