Correction of higher order aberrations in intraocular lenses
In one aspect, the present invention provides a method of designing an intraocular lens (IOL) to address variations of at least one ocular parameter in a population of patient eyes. The method can include establishing at least one eye model in which the ocular parameter can be varied over a range exhibited by the population. The eye model can be employed to evaluate a plurality of IOL designs in correcting visual acuity for eyes in the patient population. An IOL design that provides a best fit for visual performance over at least a portion of the parameter range can then be selected.
1. An intraocular lens (IOL) comprising an optic, the optic comprising an anterior surface and a posterior surface, the optic being manufactured by the process of:
establishing at least one eye model in which the ocular parameter can be varied over a range exhibited by the population,
employing the eye model to evaluate a plurality of IOL designs for visual performance for eyes in the patient population,
applying a weighting function to visual performance exhibited by the plurality of IOL designs, said function being based on distribution of the ocular parameter in the population,
selecting an IOL design that provides a best fit for visual performance over at least a portion of the range exhibited by the population;
and manufacturing at least one IOL according to the selected IOL design.
2. The IOL of claim 1 , wherein said visual performance comprises visual acuity.
3. The IOL of claim 2 , further comprising determining the best fit for visual acuity as an optimal value of a weighted visual acuity among the IOL designs.
4. The IOL of claim 2 , further comprising determining a modulation transfer function at the retina of the eye model for obtaining the visual acuity exhibited by the plurality of IOL designs.
5. The IOL of claim 1 , further comprising generating said plurality of IOL designs based on varying at least one lens design parameter.
6. The IOL of claim 1 , wherein said ocular parameter comprises ocular axial length.
7. The IOL of claim 1 , wherein said ocular parameter comprises corneal asphericity.
8. The IOL of claim 1 , wherein said ocular parameter comprises corneal radius.
9. The IOL of claim 1 , wherein said ocular parameter comprises ocular anterior chamber depth.
10. An intraocular lens (IOL) comprising an optic, the optic comprising an anterior surface and a posterior surface, the optic being manufactured by the process of:
generating a human eye model in which at least one ocular biometric parameter can be varied,
evaluating optical performance of a plurality of IOL designs by incorporating the designs in the eye model and varying said ocular parameter over at least a portion of a range exhibited by eyes in a patient population, and
applying a weighting function to visual performance exhibited by the plurality of IOL designs, said function being based on distribution of the ocular parameter in the population,
selecting one of the IOL designs that provides a desirable level of performance; and manufacturing at least one IOL according to the selected IOL design.
11. The IOL of claim 10 , wherein said ocular parameter comprises any of corneal radius, corneal asphericity, anterior chamber depth or ocular axial length.
12. The IOL of claim 10 , further comprising generating said IOL designs by varying at least one lens design parameter.
13. The IOL of claim 12 , wherein said lens design parameter comprises any of a conic constant of an aspherical lens surface, two conic constants associated with a toric lens surface or an apodization function associated with step heights at zone boundaries of a diffractive pattern disposed on a lens surface.
14. The IOL of claim 10 , wherein the step of evaluating optical performance of the plurality of IOL designs further comprises employing the eye model to determine an average visual acuity provided by that design over said ocular parameter range.
15. The IOL of claim 14 , further comprising calculating a modulation transfer function at the retina of the eye model for determining said visual acuity.
16. The IOL of claim 10 , further comprising identifying the IOL design of the plurality of IOL designs that exhibits the largest weighted average visual acuity as providing an optimal performance.
17. The IOL of claim 10 , further comprising utilizing Monte Carlo simulation for varying said ocular parameter.
18. The IOL of claim 10 , further comprising incorporating an estimate of manufacturing tolerance associated with at least one lens characteristic into the plurality of IOL designs.
19. The IOL of claim 18 , wherein said lens characteristic comprises irregularities associated with a lens surface.
20. The IOL of claim 18 , wherein said lens characteristic comprises a radius of a lens surface.
21. The IOL of claim 18 , wherein said lens characteristic comprises an asphericity of a lens surface.
22. The IOL of claim 18 , wherein said lens characteristic comprises lens thickness.