HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Chen, Y.-I Articles by Chen, T. H.-H. Search for Related Content PubMed PubMed Citation Articles by Chen, Y.-I Articles by Chen, T. H.-H.

An Interval-Censored Model for Predicting Myopic Regression after Laser In Situ Keratomileusis

¹From the Department of Ophthalmology, Taipei Hospital, Taipei, Taiwan; the ²Institute of Preventive Medicine, the ⁵Centre of Biostatistics Consultation, and the ⁶Division of Biostatistics, Graduate Institute of Epidemiology, College of Public Health, and the ³Department of Ophthalmology, National Taiwan University, Taipei, Taiwan; and the ⁴Universal Eye Center, Taipei, Taiwan.

PURPOSE. A time-varying statistical model was proposed to predict the risk of regression toward myopia after laser in situ keratomileusis (LASIK) and to identify significant predictors within a time frame.

METHODS. A total of 615 eyes of 311 patients derived from a retrospective cohort who underwent LASIK in 2003 were analyzed. Refraction outcomes were recorded at 1 day, 1 week, and 1, 3, 6, 9, and 12 months or longer after LASIK. A cross-validated design was used, to split data into trained (n = 308) and validated (n = 307) data sets. These data sets were used in an interval-censored model to predict the probability of regression toward myopia and to assess the predictors including demographic features and preoperative and postoperative variables.

RESULTS. Myopia regression was observed in 164 (26.7%) of 615 eyes during the follow-up period of 12 months or longer after LASIK. Significant predictors for myopia regression after LASIK included preoperative manifest spherical equivalent (P = <0.0001), mean preoperative central corneal curvature (P = 0.001), size of optic zone (P = 0.0043), undercorrection (P = 0.04), and age (P = 0.0734). The risk of regression toward myopia after LASIK increased rapidly within 1 month, slowed down between 1 and 6 months, and became steady after 6 months, regardless of risk group. The risk of myopia regression up to 6 months after LASIK was 21% in average-risk eyes (based on all eyes).

CONCLUSIONS. The proposed interval-censored model was useful not only for predicting the probability of myopia regression after LASIK but also for identifying the evolution of patients within low, moderate, and high-risk groups.