Related Experiment Videos
Multifocal corneal topographic changes with excimer laser photorefractive keratectomy
H Moreira1, J J Garbus, A Fasano
1Doheny Eye Institute, Los Angeles, CA 90033.
Archives of Ophthalmology (Chicago, Ill. : 1960)
|July 1, 1992
Summary
This study explored creating multifocal corneas using excimer laser photorefractive keratectomy to address myopia and presbyopia. Multifocal ablations show potential for reducing presbyopia symptoms, but may affect image quality.
Area of Science:
- Ophthalmology
- Biomedical Engineering
- Corneal Surgery
Background:
- Excimer laser photorefractive keratectomy flattens the cornea to correct myopia.
- Presbyopia in older patients limits satisfaction with refractive surgery.
- Some patients naturally develop a multifocal lens effect after surgery.
Purpose of the Study:
- To purposefully create a multifocal refractive effect in the cornea.
- To quantitatively analyze corneal topography after multifocal ablations.
- To assess the potential for reducing presbyopia symptoms.
Main Methods:
- Computer-assisted topographic analysis of corneas.
- Comparison of corneal powers in unoperated, monofocal, and multifocal ablated corneas.
- Quantitative analysis of surface power distributions.
Main Results:
- Monofocal ablations increased the range of corneal powers compared to unoperated corneas.
- Multifocal ablations resulted in a greater spread of corneal powers, often with bimodal distributions.
- These distributions suggest an achieved multifocal effect.
Conclusions:
- Multifocal ablations may offer a way to reduce presbyopia symptoms in myopic patients.
- Potential complications include decreased image contrast and monocular diplopia.
- Further research is needed to optimize this approach.