Experimental evaluation of two current-generation automated microkeratome: the Hanatome and the upratome

PURPOE: To compare flap dimenion, cut quality, and blade deterioration after reue in an experimental etting uing two current-generation microkeratome for laer-aited in itu keratomileui. METHOD: Two pivoting-head principle microkeratome, the Hanatome and the upratome, were ued to perform a corneal flap in 50 frehly enucleated pig cadaver eye, with an intended thickne of 160 μm. Provided tainle teel blade were ued from one to five time. Flap diameter wa meaured by planimetry and thickne calculated uing ultraonic pachymetry at three different location. canning electron microcopy of tromal bed and blade’ cutting edge were performed to ae the cut and blade deterioration after repeated ue. REULT: Mean flap central thickne (Hanatome/upratome) wa 151 μm (D 18)/192 μm (D 32). Progreive thinning/thickening of the flap wa oberved in the direction toward the hinge (P = .003/P = .021). Mean vertical flap diameter of 8.9 mm (D 0.3)/8.0 mm (D 0.4) differed ignificantly (P = .001). No correlation wa found between thickne and diameter (r = 0.03, P = .935/r = 0.12, P = .603). At canning electron microcopy, mooth cut were oberved with both keratome uing a new blade. Periodical chatter line at keratectomy edge were preent and were more pronounced after blade reue. Cut quality, blade deterioration, and mall tiue remnant on the blade urface were noted with repeated blade ue, epecially uing the upratome. CONCLUION: Local flap thickne and flap diameter variation are inherent to the intrument ued. Comparable cut-urface quality can be obtained with new blade. Although cut and blade deterioration appear to be minor after two reue, the preence of tiue remnant on the blade urface till limit it reue.