Abstract
Purpose:
To determine if procedure room temperature and humidity during LASIK affects refractive outcomes in a very large patient sample.
Methods:
Patients aged 18 to 75 years old who underwent LASIK at an Optical Express, Inc. location in their United Kingdom and Ireland centers from January 1, 2008 to June 30, 2011 who met inclusion criteria (including post-operative refractive goal of plano) were included. Patient age, gender, pre- and one month post-LASIK manifest refraction and flap creation technique were recorded as well as the ambient temperature and humidity during LASIK. Effect size determination, in addition to univariate and multivariate analysis was performed to characterize the relationships between LASIK procedure room temperature and humidity and post-operative refractive outcome.
Results:
202,394 eyes of 105,712 patients were included. When considering all eyes in our population, an increase of one degree Celsius during LASIK was associated with a 0.003 diopter more hyperopic refraction one month post-operatively (P=0.0094) and an increase in one percent humidity was associated with a 0.0004 more myopic refraction (P<0.0001). These effect sizes were considered clinically insignificant and were the same or similar when considering only myopic eyes, only hyperopic eyes and subgroups of eyes stratified by age and pre-operative refractive error.
Conclusions:
Procedure room temperature or humidity during LASIK was found to have no clinically significant relationship with post-operative manifest refraction in our population.
Keywords: 683 refractive surgery: LASIK •
678 refractive surgery