Evaluation of Position-induced Cyclorotation Between Wavefront Measurement and Refractive Surgery by the Iris Registration Method
Cyclorotation of eyes may be affected by motion and orientation of the head and body. An automated alignment method with the technique of iris recognition was used to assess the amount and orientation of position-induced cyclorotation between preoperative wavefront measurement and laser refractive surgery.
Eye Cyclorotation Degree
|Study Design:||Observational Model: Cohort
Time Perspective: Retrospective
|Official Title:||Evaluation of Position-induced Cyclorotation Between Wavefront Measurement and Refractive Surgery by the Iris Registration Method|
|Study Start Date:||January 2008|
|Study Completion Date:||October 2008|
|Primary Completion Date:||June 2008 (Final data collection date for primary outcome measure)|
Ninety-three consecutive patients undergoing bilateral wavefront-guided laser refractive surgery in the Department of Ophthalmology of the National Taiwan University Hospital between September 2004 and December 2007 were enrolled in this retrospective study. Before laser refractive surgery, all patients were seated in front of the Zyoptix 100 system platform (Bausch & Lomb, salt lake city, UT, USA) and received Zywave aberrometer measurement on both eyes. When patients were in the supine position for refractive surgery, an infrared camera mounted on the laser system (Technolas 217z100 excimer laser system, Bausch & Lomb)obtained iris images on undilated pupils before laser ablation. Overall cyclorotation was detected by a comparison between iris images of undilated pupils in the supine position and dilated pupils in the seated position before laser treatment. The degree and direction of position-induced cyclorotation were assessed.
|Department of Ophthalmology, National Taiwan University Hospital|
|Study Director:||Yu-Chih Hou, MD||Telephone: 886-2-23123456 Ext. 65025 Email: email@example.com|