Objective To investigate the forward shift of the posterior corneal surface and related influential factors after laser in situ keratomileusis (LASIK).Methods It was a prospective case series study.Eighty-two patients with myopia (38 males and 44 females) who had undergone LASIK at Union Hospital between December 2006 and February 2007 were retrospectively reviewed.The average age was 24.2±5.5 years,ranging from 18 to 44 years.No case of keratoconus was found during 3 years of follow-up.Intraocular pressure,corneal thickness and topography measurements were obtained with a Goldmann tonometer,ultrasonic corneal pachymeter and Orbscan Ⅱ z before and after surgery.All surgery was performed by the same surgeon using a 217Z100 Bausch & Lomb.Results After LASIK,the best fit sphere radius of the posterior corneal surface was shortened by 113.32±66.87 μm,with an average forward shift of 71.97±28.70 μm.The difference in the posterior corneal surface power between pre-and post-operation was 0.93±0.54 D.The forward shift of the posterior corneal surface showed a positive correlation with preoperative intraocular pressure (r=0.461,P<0.01),and a negative correlation with residual stromal bed thickness (r=-0.453,P<0.00).There was a forward shift of varying degrees in the posterior comeal surface in most cases,including several severe cases.But no corneal ectasia was observed during the follow-up period of 36 months.Conclusion The forward shift of the posterior corneal surface could be an inevitable response because of corneal thinning after LASIK,and a change in the posterior corneal surface showed a positive correlation with preoperative intraocular pressure and a negative correlation with residual stromal bed thickness.
张光明,张明昌,胡燕华,聂绍松. 准分子激光原位角膜磨镶术后角膜后表面前突的影响因素[J]. 中华眼视光学与视觉科学杂志, 2012, 14(12): 745-748.
ZHANG Guang-ming,ZHANG Ming-chang,HU Yan-hua,NIE Shao-song. Factors affecting the forward shift of the posterior corneal surface in laser in situ keratomileusis. Chinese Journal of Optometry Ophthalmology and Visual science, 2012, 14(12): 745-748. DOI: 10.3760/cma.j.issn.1674-845X.2012.12.012