Influence Of Times Microkeratome Blades Were Used To Corneal Flap Thickness In LASIK

PurposeTo investigate influence of times microkeratome blades were used to corneal flap quality(including corneal flap thickness,uniformity of thickness and smoothness of cut surface) in LASIK through imitating the course that corneal flaps were made on freshly enucleated swine eyes.Provide the basis for using microkeratome blades correctly for surgeons.Materials and Methods1.To freshly enucleated swine eyes as the research objects.36 freshly enucleated swine eyes were invided to 6 groups(Ⅰ-Ⅵ) according to times blades were used(1-6). CombineⅠandⅡ,ⅢandⅣ,ⅤandⅥseparately to A,B,C.2.Measure central corneal thickness,corneal refractive power and IOP.3.Imitate the course that corneal flaps were made on enucleated swine eyes and calculate central corneal flap thickness.4.Choose 3 flaps from every groups and observe uniformity of corneal flap thickness with optical microscopy.5.Choose 1 flap from three groups(Ⅰ,Ⅳ,Ⅳ)and observe smoothness of cut surface with scanning electron microscopy.Results1.There was no difference between the two groups in central corneal thickness,corneal refractive power and IOP before operation.2.The everage central corneal flap thickness ofⅠ-Ⅵgroup were 152.67±14.64μm,143.83±9.28μm,128.33±12.74μm,114.17±9.60μm,99.67±5.72μm, 70.0±12.68μm.There was no difference betweenⅠandⅡ,butⅢ-Ⅵwere different fromⅠin central corneal flap thickness.There was a negative correlation between corneal flap thickness and times blades were used.The everage corneal flap thickness of A-C were 150.75±15.39μm,121.25±13.05gm,88.33±15.10μm.There was dramatical difference between the two groups.3.With the increase in times blades were used,corneal flap became loose stroma, loss of parallel structure and uniformity of corneal flap thickness decreased with optical microscopy.4.Smoothness of cut surface decreased with the increase in times blades were used with scanning electron microscopy.Conclusions1.Corneal flap thickness became thinner with the increase in times blades were used.2.Uniformity of corneal flap thickness decreased with the increase in times blades were used.3.Smoothness of cut surface decreased with the increase in times blades were used.