Factors Predicting the Need for Retreatment after Laser Refractive Surgery

Purpose: To identify the potential risk factors that increase the likelihood of requiring retreatment after refractive surgery. Methods: This retrospective study included patients who underwent laser in situ keratomileusis or photorefractive keratectomy between January 2005 and December 2012 at the Care-Vision Laser Centers, Tel-Aviv, Israel. Patients were divided into 2 groups according to whether they underwent additional refractive surgery (retreatment) during the study period. Results: Overall, 41,504 eyes (n = 21,313) were included in the final analysis of this study. Throughout the study period, there was a significant reduction in the 2-year annual retreatment rates with a decline from 4.52% for primary surgeries done in 2005 to 0.18% for surgeries performed in 2012 (quadratic R2 = 0.96, P , 0.001). The retreatment group had significantly higher preoperative age, maximum keratometric power, sphere, cylinder, and better bestcorrected visual acuity. They were more likely to have preoperative hyperopia, photorefractive keratectomy as opposed to laser in situ keratomileusis, intraoperative higher humidity conditions and lower temperature, and higher ablation depths. Significant differences in retreatment rates were found between the 5 high-volume surgeons (.1500 procedures performed) ranging from 0.48 to 3.14% (P , 0.0001). Multiple logistic regression analysis demonstrated that age, astigmatism, hyperopia, temperature, and surgeon's experience all significantly affected the need for retreatment. Conclusions: The following factors significantly increase the need for refractive retreatment: older preoperative age, higher degrees of astigmatism, hyperopia, colder operating room temperature, and less surgeon experience. Some of these factors may be incorporated into nomograms to reduce future retreatment rates.