Long-time follow-up study of keratocyte and endothelial cell after LASIK using an in vivo confocal microscopy

Objective To observe the changes of keratocyte and endothelial cell induced by myopic LASIK using an in vivo confocal microscopy at long-time follow-up.Methods Sixty-eight patients (68 eyes) who had undertook LASIK were divided into high myopia group and low-moderate myopia group.The average follow-up time was (16.0±9.5) months(range from 6～44 months).Sixty-one patients(122 eyes) who were defined as myopia were choosen as the control group.All eyes were examined by in vivo confocal microscopy.Images were recorded and analyzed the effect of LASIK on corneal stroma and endothelium.Results In the high myopia group,the density of keratocyte quantified in the anterior and posterior stroma decreased significantly(t=- 0.407 7,P=0.000),and the density of endothelial cells decreased too.The percentage of its pantomorphia increased while its heteromorphism decreased with significant differences.The morphologic of keratocyte and the density of keratocyte quantified in interface showed abnormality.The density of keratocyte quantified(562 counts·mm -2±86 counts·mm -2)in acellular area decreased significantly than normal.The mean depth of acellular area were not correlative with the manifest spherical equivalent,operation time and ages.Conclusion Proper laser power has less effect on the corneal biology for patients with low and medium myopia,but more in the high myopic group,while LAISK surgery must be cautious taken for high myopic eyes.