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Aspheric photorefractive keratectomy with excimer laser
T Seiler1, U Genth, A Holschbach
1University Eye Clinic, Free University of Berlin, Germany.
Refractive & Corneal Surgery
|May 1, 1993
Summary
Aspheric photorefractive keratectomy improves visual quality after myopia correction. This new method reduces side effects like glare and halos compared to standard spherical corrections, enhancing optical homogeneity.
Area of Science:
- Ophthalmology
- Corneal Surgery
- Refractive Surgery
Background:
- Spherical aberration is common after excimer laser keratectomy.
- Corneal shape influences night vision side effects like glare and halos.
- Aspheric corneal modifications may reduce these visual disturbances.
Purpose of the Study:
- To compare the efficacy of aspheric versus standard spherical algorithms in photorefractive keratectomy for myopia.
- To evaluate the impact of aspheric correction on visual quality and aberrations.
Main Methods:
- Fifteen patients underwent bilateral photorefractive keratectomy for myopia.
- One eye was treated with a standard spherical algorithm, the fellow eye with an aspheric algorithm.
- Patients were followed for 6 to 18 months, with topographic and aberration analysis.
Main Results:
- No patients reported worse halos with aspheric correction; five reported worse halos with spherical correction.
- Aspheric correction resulted in a significantly larger effective clear zone (3.43 mm vs. 3.16 mm).
- Effective spherical aberration was significantly reduced with aspheric correction.
Conclusions:
- Aspheric photorefractive keratectomy offers better optical homogeneity compared to standard spherical corrections.
- Aspheric algorithms may be a superior approach for myopia correction to minimize visual side effects.