Optimal IOL shape factors for human eyes

• US 20060227286A1
• Filed: 04/04/2006
• Published: 10/12/2006
• Est. Priority Date: 04/05/2005
• Status: Abandoned Application

• Current Assignee: Novartis Ag
• Original Assignee: Novartis Ag
• Inventors: Simpson, Michael J., Zhang, Xiaoxiao, Karakelle, Mutlu, Xie, Jihong, Van Noy, Stephen J., Hong, Xin, Stanley, Dan
• Application Number:
  US11/397,305
• Publication Number:
  US 20060227286A1
• Time in Patent Office: Days
• US Class Current: 351/159
• CPC Class Codes: A61F 2/1613 having special lens configurations, e.g. multipart lenses; having particular optical properties, e.g. pseudo-accommodative lenses, lenses having aberration corrections, diffractive lenses, lenses for variably absorbing electromagnetic radiation, lenses having variable focus
• CPC Class Codes: A61F 2/1637 Correcting aberrations caused by inhomogeneities; correcting intrinsic aberrations, e.g. of the cornea, of the surface of the natural lens, aspheric, cylindrical, toric lenses
• CPC Class Codes: G02C 7/02 Lenses; Lens systems ; Methods of designing lenses

Abstract

The present invention provides an ophthalmic lens (e.g., an intraocular lens) having an optic with an anterior surface and a posterior surface, which exhibits a shape factor (defined as a ratio of the sum of the anterior and posterior curvatures to the difference of such curvatures) in a range of about −0.5 to about 4. In a related aspect, the shape factor of the optic lies in a range of about 0 to about 2. The above shape factors give rise to a plurality of different lens shapes, such as concave-convex, plano-convex and plano-concave.

Claims

1. An ophthalmic lens, comprising

an optic having an anterior surface and a posterior surface,

said optic exhibiting a shape factor in a range of about −

0.5 to about 4.

2. The ophthalmic lens of claim 1, wherein said optic exhibits a shape factor in a range of about 0 to about 2.

3. The ophthalmic lens of claim 1, wherein said optic comprises a biocompatible polymeric material.

4. The ophthalmic lens of claim 3, wherein the polymeric material is selected from the group consisting of acrylic, silicone and hydrogel materials.

5. The ophthalmic lens of claim 1, wherein both of said surfaces have a generally convex profile.

6. The ophthalmic lens of claim 1, wherein one of said surfaces has a generally convex profile and the other surface has a substantially flat profile.

7. The ophthalmic lens of claim 1, wherein one of said surfaces has a generally concave profile and the other surface has a substantially flat profile.

8. The ophthalmic lens of claim 1, wherein one of said surfaces has a generally concave profile and the other surface has a generally convex profile.

9. The ophthalmic lens of claim 1, wherein at least one of said surfaces is characterized by an aspherical base profile.

10. The ophthalmic lens of claim 9, wherein said aspheric base profile is characterized by a conic constant (Q) in a range of about −

73 to about −

27.

11. The ophthalmic lens of claim 1, wherein said lens comprises an intraocular lens.

12. An ophthalmic lens, comprising

an optic having an anterior surface and a posterior surface,

at least one of said surfaces being characterized by an aspherical base profile defined by the following relation:

$z=\frac{c<br><br>\text{\hspace{1em}<br><br>}<br><br>r^2}{1+\sqrt{1-\left(1+k\right)<br><br>c^2<br><br>r^2}}$

wherein,

c denotes the curvature of the surface at its apex (at its intersection with the optical axis),

r denotes the radial distance from the optical axis, and

k denotes the conic constant,

wherein

c is in a range of about 0.0152 mm<sup>−

1</sup> to about 0.0659 mm<sup>−

1</sup>,

r is in a range of about 0 to about 5 mm, and

k is in a range of about −

73 to about −

27,

wherein said optic exhibits a shape factor in a range of about −

0.5 to about 4.

13. The ophthalmic lens of claim 12, wherein said optic exhibits a shape factor in a range of about 0 to about 2.

14. The ophthalmic lens of claim 12, wherein said lens comprises an intraocular lens.

15. The ophthalmic lens of claim 12, wherein said surfaces cooperatively provide a refractive optical power in a range of about 16 D to about 25 D.

16. The ophthalmic lens of claim 12, wherein said optic is formed of a biocompatible polymeric material.

17. An intraocular lens adapted for implantation in an eye having a corneal radius equal to or less than about 7.1 mm, comprising

an optic having an anterior surface and a posterior surface,

said optic exhibiting a shape factor in a range of about −

0.5 to about 4.

18. The intraocular lens of claim 17, wherein optic exhibits a shape factor in a range of about +0.5 to about 4.

19. The intraocular lens of claim 17, wherein said optic exhibits a shape factor in a range of about 1 to about 3.

20. An intraocular lens adapted for implantation in an eye having a corneal radius in a range of about 7.1 to about 8.6 mm, comprising

an optic having an anterior surface and a posterior surface,

said optic exhibiting a shape factor in a range of about 0 to about 3.

21. The intraocular lens of claim 20, wherein said optic exhibits a shape factor in a range of about +0.5 to about 3.

22. The intraocular lens of claim 20, wherein said optic exhibits a shape factor in a range of about 1 to about 2.

23. An intraocular lens adapted for implantation in an eye having a corneal radius equal to or greater than about 8.6 mm, comprising

an optic having an anterior surface and a posterior surface,

said optic exhibiting a shape factor in a range of about +0.5 to about 2.

24. The intraocular lens of claim 23, wherein said optic exhibits a shape factor in a range of about 1 to about 2.

25. An intraocular lens adapted for implantation in an eye having an axial length equal to or less than about 22 mm, comprising

an optic having an anterior surface and a posterior surface,

said optic having a shape factor in a range of about 0 to about 2.

26. The intraocular lens of claim 25, wherein the optic exhibits a shape factor in a range of about 0.5 to about 2.

27. An ophthalmic lens, comprising

an optic having an anterior surface and a posterior surface,

at least one of said surfaces having an aspherical profile characterized by a conic constant in a range of about −

73 to about −

27,

wherein said optic exhibits a shape factor in a range of about −

0.5 to about 4.

28. The ophthalmic lens of claim 27, wherein said aspherical profile is characterized by a conic constant in a range of about −

73 to about −

27, and said optic exhibits a shape factor in a range of about 0 to about 2.

29. A method of correcting vision, comprising

selecting an IOL comprising an optic exhibiting a shape factor in a range of about −

0.5 to about 4 for implantation in an eye having a corneal radius equal or less than about 7.1 mm.

30. The method of claim 29, wherein the shape factor of the optic is selected to be in a range of about +0.5 to about 4.

31. A method of correcting vision, comprising

selecting an IOL comprising an optic exhibiting a shape factor in a range of about 0 to about 3 for implantation in an eye having a corneal radius in a range of about 7.1 mm to about 8.6 mm.

32. The method of claim 31, wherein the shape factor of the optic is selected to be in a range of about +0.5 to about 3.

33. A method of correcting vision, comprising

selecting an IOL comprising an optic exhibiting a shape factor in a range of about 0.5 to about 2 for implantation in an eye having a corneal radius equal to or greater than about 8.6 mm.

34. A method of correcting vision, comprising

selecting an IOL comprising an optic exhibiting a shape factor in a range of about 0 to about 2 for implantation in an eye having an axial length equal to or less than about 22 mm.

35. The method of claim 34, wherein a shape factor of the optic is selected to be in a range of about 0.5 to about 2.

36. A method of designing an ophthalmic lens, comprising

defining an error function indicative of variability in performance of a lens in a patient population based on estimated variability in one or more biometric parameters associated with that population, and

selecting a shape factor for the lens that reduces said error function relative to a reference value.

37. The method of claim 36, wherein said error function further incorporates an estimated error in optical power correction provided by the lens.

38. The method of claim 37, wherein said error function further incorporates an estimated aberration error.

39. The method of claim 38, wherein said error function (RxError) is defined by the following relation:

40. The method of claim 39, wherein Δ

Biometric is defined by the following relation;

Δ

Biometric=√

{square root over (Δ

k²+Δ

AL²+Δ

ACD²)}

wherein,

Δ

k denotes error in keratometric measurements,

Δ

AL denotes error in axial length measurements, and

Δ

ACD denotes error in anterior chamber depth measurements.

41. The method of claim 39, wherein Δ

Aberration is defined by the following relation;

Δ

Aberration=√

{square root over (Δ

Astig²+Δ

SA²+Δ

Other²)}

wherein,

Δ

Astig represents variability due to astigmatic aberration,

Δ

SA represents variability due to spherical aberration, and

Δ

Other represents variability due to other aberrations.

42. The method of claim 39, wherein Δ

IOLPower is defined by the following relation;

Δ

IOLPower=√

{square root over (Δ

IOLStep²+Δ

IOLTol²+Δ

ELP²)}

wherein,

Δ

IOLStep represents variability caused by difference between the lens power and a power need of a patient,

Δ

IOLTol represents manufacturing power tolerance, and

Δ

ELP represents variability in a shift of the lens effective position within the eye.