Related Experiment Videos
Simplified formulas for lathing aphakic epikeratophakia lenses
1Moorfields Eye Hospital, London, England.
Ophthalmic Surgery
|May 1, 1989
Summary
Simplified geometric formulas aid in calculating radii for aphakic epikeratophakia lenses. These new formulas account for lens thinning and dehydration, with over 80% of lenses achieving expected power.
Area of Science:
- Ophthalmology and Optometry
- Biomedical Engineering
Background:
- Aphakic epikeratophakia lens fabrication requires precise geometric calculations.
- Existing methods for calculating lens radii can be complex and time-consuming.
Purpose of the Study:
- To simplify the geometric formulas used for lathing aphakic epikeratophakia lenses.
- To develop a calculation method that accounts for postoperative lens thinning and pre-lathing dehydration.
Main Methods:
- Development of simplified, geometrically based formulas for calculating radii of cut.
- Inclusion of parameters to compensate for lens thinning on host cornea.
- Incorporation of variables for desired pre-lathing dehydration levels.
Main Results:
- The simplified formulas enable easy calculation of optical and wing zone radii.
- Over 80% of fabricated lenses were within 3 diopters of the expected refractive power.
- The method effectively compensates for expected postoperative changes in lens geometry.
Conclusions:
- The new formulas provide a more accessible and accurate method for aphakic epikeratophakia lens fabrication.
- This simplification can improve the efficiency and success rate of custom lens production.
- The approach offers a practical solution for achieving precise lens power in aphakic patients.