Compound modulation transfer function for laser surgery and other optical applications
View Patent ↗Methods, devices, and systems establish an optical surface shape that mitigates or treats a vision condition in a patient. An optical surface shape for a particular patient can be determined using a set of patient parameters for the specific patient by using a compound modulation transfer function (CMTF). The compound modulation transfer function can include a combination of modulation transfer functions (MTF's) at a plurality of distinct frequencies.
1. A method for treating or mitigating a vision condition of an eye in a particular patient, the method comprising:
selecting a gauge of optical quality appropriate for the vision condition of the eye;
inputting a patient parameter specific for the particular patient;
determining an optical surface shape for the particular patient using the patient parameter specific for the particular patient with a compound modulation transfer function (CMTF), the compound modulation transfer function comprising a combination of modulation transfer functions (MTF's) at a plurality of distinct frequencies; and
mitigating or treating the vision condition of the eye in the patient by administering to the patient a procedure selected from the group consisting of:
ablating a corneal surface of the patient to provide a corneal surface shape that corresponds to the optical surface shape,
providing the patient with a contact lens or spectacle lens that has a shape that corresponds to the optical surface shape, and
providing the patient with an intra-ocular lens that has a shape that corresponds to the optical surface shape;
wherein the gauge of optical quality comprises a compound modulation transfer function (CMTF) parameter.
2. The method of claim 1 , wherein the CMTF is normalized to a diffraction limited MTF.
3. The method of claim 2 , wherein the MTF's at the plurality of distinct frequencies are combined in a linear combination.
4. The method of claim 3 , wherein the CMTF is calculated according to the following formula
C
M
T
F
=
1
n
∑
i
=
1
n
α
i
h
i
,
where n is the number of MTF curves, α i is the reciprocal of the ith diffraction-limited MTF, and h i is the ith MTF curve.
5. The method of claim 1 , wherein the CMTF is calculated according to the following formula
F (ν)=(α 1 MTF 1 +α 2 MTF 2 +α 3 MTF 3 )/3
where MTF 1 , MTF 2 , and MTF 3 comprise MTF values ranging from about 5 cycles/degree to about 20 cycles/degree, from about 15 cycles/degree to about 45 cycles/degree, and from about 30 cycles/degree to about 75 cycles/degree, respectively.
6. The method of claim 5 , wherein MTF 1 , MTF 2 , and MTF 3 comprise MTF values of 10 cycles/degree, 20 cycles/degree and 30 cycles/degree, respectively.
7. The method of claim 5 , wherein weighting coefficients α 1 , α 2 , α 3 are chosen so that 1/α 1 , 1/α 2 , 1/α 3 are the diffraction-limited MTF at these spatial frequencies, respectively.
8. The method of claim 5 , wherein MTF 1 , MTF 2 , and MTF 3 comprise MTF values of 10 cycles/degree, 20 cycles/degree and 30 cycles/degree, respectively, and the vision condition comprises presbyopia.
9. The method of claim 1 , wherein one MTF at a spatial frequency corresponds to one angular extend of features of targets, and the compound MTF can be calculated as linear combination of MTF at different spatial frequencies normalized by a diffraction-limited MTF.
10. The method of claim 9 , wherein the CMTF is used to predict visual outcome.
11. The method of claim 1 , wherein the CMTF is calculated according to the following formula
C
M
T
F
(
v
)
=
1
n
α
i
M
T
F
i
(
v
)
where nu is visual vergence and α i is the reciprocal of the i-th diffraction-limited MTF.
12. The method of claim 11 , wherein the CMTF comprises three MTF curves at 10, 20 and 30 cycles per degree.
13. The method of claim 12 , wherein the CMTF comprises a value of about 1.
14. The method of claim 13 , wherein the CMTF comprises a value between about 0.2 and about 0.3.
15. The method of claim 1 , wherein the CMTF is calculated over a vergence of about 3 diopters.
16. The method of claim 1 , wherein the MTF's at the plurality of distinct frequencies comprise MTF's at 10, 20, and 30 cycles per degree.
17. The method of claim 1 , wherein the MTF's at the plurality of distinct frequencies comprise MTF's at 15, 30, and 60 cycles per degree.
18. The method of claim 1 , wherein the MTF's at the plurality of distinct frequencies comprise MTF's at 30, 45, and 60 cycles per degree.
19. The method of claim 1 , wherein the MTF's at the plurality of distinct frequencies comprise at least one MTF ranging from about 5 cycles/degree to about 20 cycles/degree, at least one MTF ranging from about 15 cycles/degree to about 45 cycles/degree, and at least one MTF ranging from about 30 cycles/degree to about 75 cycles/degree.
20. The method of claim 1 , wherein the CMTF is used in an optimization routine as a goal function.
21. The method of claim 1 , wherein the vision condition comprises presbyopia.
22. The method of claim 1 , wherein the set of patient parameters comprises a patient parameter selection from the group consisting of a pupil dimension, a residual accommodation, and a vergence.
23. A method of evaluating the effectiveness of a refractive correction administered to treat a vision condition of an eye of a particular patient, comprising:
inputting a patient parameter specific for the particular patient; and
evaluating the effectiveness of the administered refractive correction using the patient parameter specific for the patient with a compound modulation transfer function (CMTF), the compound modulation transfer function comprising a combination of modulation transfer functions (MTF's) at a plurality of distinct frequencies.
24. A method of predicting the effectiveness of a refractive correction proposed to treat a vision condition of an eye of a particular patient, comprising:
inputting a patient parameter specific for the particular patient; and
predicting the effectiveness of the proposed refractive correction using the patient parameter specific for the patient with a compound modulation transfer function (CMTF), the compound modulation transfer function comprising a combination of modulation transfer functions (MTF's) at a plurality of distinct frequencies.