Apparatus, systems and methods for improving visual outcomes for pseudophakic patients

Patent metadata

Field	Value
Publication number	US-10088384-B2
Application number	US-201715817050-A
Country	US
Kind code	B2
Filing date	Nov 17, 2017
Priority date	Dec 4, 2014
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

A system and method of characterizing through-focus visual performance of an IOL using metrics based on an area under the modulation transfer function for different spatial frequencies at different defocus positions of the IOL. Also disclosed is a system and method of characterizing through-focus visual performance of an IOL using a metric based on an area under a cross-correlation coefficient for an image of a target acquired by the IOL at different defocus positions of the IOL.

First claim

We claim:

1. An optical system configured to predict clinical visual performance of an intraocular lens (IOL), the system comprising:
a measurement device configured to acquire a plurality of images of a target including objects with different spatial frequencies and obtain modulation transfer function (MTF) and/or phase transfer function (PTF) at different spatial frequencies for different defocus positions of the IOL in a vision range from the acquired plurality of images, the measurement device comprising:
a processor configured to execute programmable instructions stored in a non-transitory computer storage medium to:
calculate at least one preclinical metric selected from:
an area under the MTF (MTFa) obtained by integrating preclinical through focus MTF measurements obtained for different spatial frequencies between 0 cycles per mm and 200 cycles per mm for each of the different defocus positions;
a cross correlation coefficient (X-cor) corresponding to a convolution of a reference image and the plurality of images acquired by the measurement device at each of the different defocus positions;
a weighted MTF (wMTF) obtained by integrating a product of a threshold contrast sensitivity (CS th ) and through focus MTF measurements obtained for different spatial frequencies between 0 cycles per mm and 200 cycles per mm for each of the different defocus positions; and
a weighted OTF (wOTF) obtained by integrating a product of a threshold contrast sensitivity (CS th ), through focus MTF measurements, and cosine of the PTF obtained for different spatial frequencies between 0 cycles per mm and 200 cycles per mm for each of the different defocus positions; and
obtain a simulated visual acuity (VA) at different defocus positions of the intraocular lens (IOL) from correlating the calculated at least one preclinical metric with clinical data that predicts the VA in different IOL models, or obtain a simulated contrast sensitivity (CS) of the intraocular lens (IOL) from correlating the calculated at least one preclinical metric with clinical data that predicts the CS in different IOL models.

2. The system of the claim 1 , wherein the maximum of the simulated VA is the best focus position of the metric and is used to define the depth of focus of each evaluated IOL design.

3. The system of the claim 1 , wherein the simulated VA and CS is used to set preclinical levels related to clinical effectiveness and safety requirements.

4. The system of claim 1 , wherein the objects have spatial frequencies between about 0 cycles per mm (cpmm) and 150 cpmm.

5. The system of claim 1 , wherein the target is selected from the group consisting of: an optotype; a slit; a 1951 USAF picture chart; and a subset of bars from a 1951 USAF picture chart.

6. The system of claim 1 , wherein the simulated VA calculated from the at least one preclinical metric is fit with a function, the fitted function associated with a slope and a correlation coefficient.

7. The system of claim 1 , wherein the processor is configured to calculate a degree of monotonic decrease, the monotonic decrease being a product of the slope and the correlation coefficient of the fitted function.

8. The system of claim 1 , wherein the processor is configured to calculate a degree of tolerance to refractive errors, the tolerance to refractive errors being related to the slope of the fitted function in a determined defocus range.

9. The system of claim 1 , wherein the simulated CS is calculated from the at least one preclinical metric is fit with a function, the fitted function being associated with a slope and a correlation coefficient.

10. The system of the claim 9 , wherein the processor is configured to calculate a degree of tolerance to refractive errors, the tolerance to refractive errors being related to the slope of the fitted function in a determined defocus range.

11. An optical system configured to predict the clinical visual performance of an intraocular lens (IOL) at an intermediate vision distance, the system comprising:
a measurement device configured to acquire a plurality of images of a target including objects with different spatial frequencies and obtain modulation transfer function (MTF) and/or phase transfer function (PTF) at different spatial frequencies for different defocus positions of the IOL in the intermediate distance vision from the acquired plurality of images, the measurement device comprising:
a processor configured to execute programmable instructions stored in a non-transitory computer storage medium to:
calculate at least one preclinical metric selected from:
an area under the MTF (MTFa) obtained by integrating preclinical through focus MTF measurements obtained for different spatial frequencies between 0 cycles per mm and 200 cycles per mm for each of the different defocus positions;
a cross correlation coefficient (X-cor) corresponding to a convolution of a reference image and the plurality of images acquired by the measurement device at each of the different defocus positions for the acquired plurality of images at each of the different defocus positions;
a weighted MTF (wMTF) obtained by integrating a product of a threshold contrast sensitivity (CS th ) and through focus MTF measurements obtained for different spatial frequencies between 0 cycles per mm and 200 cycles per mm for each of the different defocus positions; and
a weighted OTF (wOTF) obtained by integrating a product of a threshold contrast sensitivity (CS th ), through focus MTF measurements, and cosine of the PTF obtained for different spatial frequencies between 0 cycles per mm and 200 cycles per mm for each of the different defocus positions;

calculate at least one preclinical metric selected from:
an area under the MTFa (AU MTFa) for the different defocus positions;
an area under the X-cor (AU X-cor) for the different defocus positions;
an area under the wMTF (AU wMTF) for the different defocus positions; and
an area under the wOTF (AU wOTF) for the different defocus positions; and

obtain a correlation of the calculated at least one preclinical metric with clinical data that predicts the AU Defocus curve of the IOL, or obtain a simulated AU Defocus curve at different defocus positions of the IOL from correlating the calculated at least one preclinical metric with clinical data that predicts the intermediate performance in different IOL models.

12. The system of claim 11 , wherein the objects have spatial frequencies between about 0 cycles per mm (cpmm) and 150 cpmm.

13. The system of claim 11 , wherein the target is selected from the group consisting of: an optotype; a slit; a 1951 USAF picture chart; and a subset of bars from a 1951 USAF picture chart.

Assignees

• Amo Groningen Bv

Inventors

• Alarcon Heredia Aixa
• Canovas Vidal Carmen
• Rosén Robert
• Weeber Hendrik A
• Piers Patricia Ann

Classifications

• G01M11/0292 Primary

  of objectives by measuring the optical modulation transfer function (photometry G01J) · CPC title

• G16H50/50

  for simulation or modelling of medical disorders · CPC title

• G01M11/0235

  by measuring multiple properties of lenses, automatic lens meters · CPC title

• G06F19/3437

  Physics · mapped topic

• G16Z99/00 Primary

  Subject matter not provided for in other main groups of this subclass · CPC title