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Rotational malposition during laser in situ keratomileusis
Anil U Swami1, Roger F Steinert, Winifred E Osborne
1New England Eye Center, Tufts University School of Medicine, Boston, Massachusetts, USA.
American Journal of Ophthalmology
|April 5, 2002
Summary
Laser vision correction can have rotational malposition errors. This study found a mean misalignment of 4.1 degrees in eyes undergoing laser in situ keratomileusis, potentially impacting astigmatism correction.
Area of Science:
- Ophthalmology
- Refractive Surgery
- Corneal Surgery
Background:
- Laser in situ keratomileusis (LASIK) is a common procedure for correcting refractive errors.
- Rotational malposition during LASIK can lead to suboptimal visual outcomes.
- Accurate alignment is crucial for effective astigmatism correction.
Purpose of the Study:
- To quantify the degree of rotational malposition in eyes undergoing LASIK.
- To assess the prevalence of significant rotational misalignment.
- To evaluate the potential impact of malposition on astigmatism correction accuracy.
Main Methods:
- Prospective observational study involving 240 eyes of 169 patients.
- Patients underwent LASIK for myopic or hyperopic astigmatism.
- Preoperative upright eye marking and intraoperative supine rotational measurement were performed.
Main Results:
- The mean torsional misalignment was 4.1 +/- 3.7 degrees.
- Right eyes showed a mean misalignment of 3.8 +/- 3.7 degrees; left eyes showed 4.2 +/- 3.6 degrees.
- 8% of eyes (20 eyes) exhibited a deviation greater than 10 degrees.
Conclusions:
- A 4-degree misalignment could cause a 14% astigmatism undercorrection; a 10-degree misalignment could cause a 35% undercorrection.
- Preoperative marking and intraoperative alignment may minimize astigmatism correction errors.
- Addressing rotational malposition is important for optimizing LASIK outcomes.