Related Experiment Video
Updated: Aug 11, 2026
05:54
Real-Time Dynamic Navigation System for the Precise Quad-Zygomatic Implant Placement in a Patient with a Severely Atrophic Maxilla
Published on: October 18, 2021
Using a reference point and videokeratography for intraoperative identification of astigmatism axis
A Suzuki1, N Maeda, H Watanabe
1Department of Ophthalmology, Osaka University Medical School, Japan.
Journal of Cataract and Refractive Surgery
|February 11, 1998
Summary
Intraoperative astigmatism axis identification without reference points can lead to significant misalignment, reducing surgical effectiveness. Using reference points and preoperative imaging can improve accuracy for astigmatic correction.
Area of Science:
- Ophthalmology
- Surgical Optics
Background:
- Accurate astigmatism axis identification is crucial for successful refractive and cataract surgeries.
- Intraoperative methods without reference points may introduce errors in axis determination.
Purpose of the Study:
- To quantify the astigmatism axis misalignment from intraoperative identification without reference points.
- To assess the impact of this misalignment on surgical outcomes.
Main Methods:
- Evaluated 38 eyes (refractive error) and 32 eyes (cataract).
- Marked a conjunctival point on the estimated intraoperative horizontal axis.
- Compared the marked axis to the seated videokeratography-determined axis to measure misalignment.
Main Results:
- Mean axial misalignment was 4.4 degrees, potentially causing a 15% loss of surgical effect.
- Maximal misalignment reached 14 degrees, correlating to a 48% loss of astigmatic correction.
Conclusions:
- Intraoperative astigmatism axis identification without reference points can significantly reduce surgical efficacy due to misalignment.
- Preoperative videokeratography and the use of reference points are recommended for enhanced accuracy.
