Evaluation of the predictability of ablation depth in photorefractive procedures by Zeiss MEL80 and VISX Star S4 excimer laser / 眼科

ABSTRACT

Objective To evaluate the predictability of ablated depth in photorefractive procedures by Zeiss MEL80 and VISX Star S4 excimer laser.Design Prospective,comparative case series.Participants 168 eyes of 84 people with myopia and cylinder.Main Outcome Measures Corneal thickness and ablated depth.Methods The thickness of cornea by Zeiss MEL80 and VISX Star S4 were measured by anterior segment OCT.The actuality ablated depth and calculated depth were compared.Results There were no significant differences between actuality ablated depth and calculated depth in Zeiss MEL80.And in VISX Star S4,the actuality ablated depth was more than calculated depth.Linear regression of changes in ablated depth on myopia and cylinder yielded the following formulaus:△ablated depth(VISX Star S4)= 2.324 *|myopia|+ 5.270 *|cylinder|-6.772.Conclusions Different excimer laser has different changes between actuality ablated depth and calculated depth.To guarantee the safety of LASIK,Ophthalmologists should know the characteristics of the excimer laser.