Predictive Model for Myopic Regression after Laser in Situ Keratomileusis (LASIK)
Date Issued
2005
Date
2005
Author(s)
Chen, Yun-i
DOI
en-US
Abstract
Objectives: To evaluate the effects of preoperative characteristics on refractive outcomes (myopic regression) after laser in situ keratomileusis (LASIK) for myopia and myopic astigmatism and to develop a predictive model to predict myopic regression after LASIK.
Setting: Universal Eye Center, an ophthalmology clinic franchise, Taipei, Taiwan
Methods: The medical records of 615 eyes of 311 patients undergoing LASIK from June 2003 to Dec 2003 were retrospectively reviewed. The surgeries were performed by one experienced surgeon using the Nidek's Excimer Laser EC-5000. Preoperative variables such as refraction errors, corneal thickness, keratometry reading, intraocular pressure (IOP), basic tear secretion (Schirmer test), ablation depth of transition zone and optic zone, diameter of optic zone and transition zone were collected from chart reviews. Age, sex were also recorded. Postoperative examinations of refraction errors were done 1 day, 1 week, 1, 3, 6, 12 months or even more if it is feasible. Three types of predictive models including logistic regression mode, Cox proportional hazards regression model, and interval-censored model were adopted to develop predictive model for estimating the probability of myopic regression after LASIK given specific time of follow-up.
Results: According to the logistic analysis, greater manifest refraction errors, lower preoperative keratometry reading, smaller size of optic zone, greater undercorrection and older age (borderline significance) lead to higher probability of myopic regression after LASIK. After taking into account time to myopic regression, the results of Cox proportional hazards regression model revealed that the variables identified in the logistic regression model except age, led to higher probability of earlier myopic regression. Similar findings were noted while using interval-censored model. According to ROC curve analysis, the predictive validity of the three models were rather identical.
Conclusions: A retrospective cohort with a cross-validated design was employed to identify significant preoperative variables associated with myopic regression covering all eyes with mild and severe regression after LASIK. Three predictive models, logistic regression, Cox proportional hazards regression model, and interval-censored model, were successfully developed on the basis of these associations to predict the probability of myopic regression by follow-up time.
Subjects
近視回退
雷射原位角膜成型術
myopic regression
laser in situ keratomileusis (LASIK)
Type
thesis
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