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Cylinder Axis Agreement: Unexpected Scenarios.
1Department of Ophthalmology, Faculty of Medicine, University of Alexandria, Alexandria, Egypt.
Clinical Ophthalmology (Auckland, N.Z.)
|April 14, 2020
Summary
Cylinder axis measurements from manifest refraction, cycloplegic refraction, and two Allegro devices show significant agreement. However, a small percentage of eyes exhibited unexpected discrepancies between the Allegro devices, highlighting potential variability in refractive surgery planning.
Area of Science:
- Ophthalmology
- Optometry
- Refractive Surgery
Background:
- Astigmatism correction is a key goal in refractive surgery.
- Accurate cylinder axis measurement is crucial for successful outcomes.
- Comparing different diagnostic tools for astigmatism is essential.
Purpose of the Study:
- To evaluate cylinder axis agreement between manifest refraction (MR), cycloplegic refraction (CR), Allegro Oculyzer II, and Allegro Topolyzer-Vario.
- To assess the reliability of these methods for refractive surgery planning.
Main Methods:
- Retrospective study of 156 eyes from 82 patients undergoing PRK or LASIK.
- Cylinder axis measured using MR, CR, Allegro Oculyzer II, and Allegro Topolyzer-Vario.
- Agreement assessed using intraclass correlation coefficient, Pearson correlation coefficient, and Bland-Altman analysis.
Main Results:
- Statistically significant cylinder axis agreement found between all four measurement methods (p <0.001).
- A small but unexpected discrepancy (2.5% of eyes) was noted between Allegro Oculyzer II and Allegro Topolyzer-Vario cylinder axis measurements.
Conclusions:
- While good agreement exists, minor discrepancies in cylinder axis measurements can occur between diagnostic tools.
- These findings emphasize the need for careful consideration of measurement variability in refractive surgery.
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