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CompletedNCT00943163Updated Jul 22, 2009

Evaluation of Position-induced Cyclorotation Between Wavefront Measurement and Refractive Surgery by the Iris Registration Method

An observational study in Eye Cyclorotation Degree and Pupil Shift, sponsored by National Taiwan University Hospital. Completed at 1 site in Taiwan. Per ClinicalTrials.gov, last updated 2009-07-22.

Sponsored by National Taiwan University Hospital · Observational

Study type
Observational
Model
Cohort
Time perspective
Retrospective
Enrollment
93
Sex
All
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Study summary

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.

Read the detailed description

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.

02

Conditions studied

  • Eye Cyclorotation Degree
  • Pupil Shift

Keywords

  • cyclorotation
  • pupil
  • laser refractive surgery
03

In context

Lead sponsor

National Taiwan University Hospital is the lead sponsor of 2,563 studies on the registry; 569 are open to participants now.

Of its 11 completed or terminated interventional studies of FDA-regulated products, 2 (18%) have results posted.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
Child (0–17), Adult (18–64), Older adult (65+)
Sexes eligible
All
Accepts healthy volunteers
Yes
Sampling method
Non-probability sample

Study population

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.

Inclusion criteria

  • patients undergoing bilateral wavefront-guided laser refractive surgery

Exclusion criteria

Exclusion Criteria:

  • patients with strabismus, extraocular muscle palsy, muscle restriction or other diseases interfering normal ocular movement.
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Study design

Observational model
Cohort
Time perspective
Retrospective
Enrollment
93 participants (actual)
06

Study locations

1 site
  • Department of Ophthalmology, National Taiwan University Hospital
    Taipei, Taiwan
07

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jul 22, 2009, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT00943163
Lead sponsor
National Taiwan University Hospital
First posted
Jul 22, 2009
Start date
Jan 2008
Primary completion
Jun 2008
Completion
Oct 2008
Last update
Jul 22, 2009

Study contacts

Yu-Chih Hou, MD
study director · Telephone: 886-2-23123456 Ext. 65025 Email: ychou51@ntu.edu.tw

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Jul 2009. You cannot join it, but the record below documents what was studied.

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