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CN-116634919-B - Automated assessment of human lens capsule stability

CN116634919BCN 116634919 BCN116634919 BCN 116634919BCN-116634919-B

Abstract

A method for assessing a lens capsule stability condition in an eye of a human patient includes directing electromagnetic energy in a predetermined spectrum via an energy source onto a pupil of the eye concurrently after movement of the eye causes an eye saccade to occur therein. The method also includes acquiring images of the eye indicative of the saccades of the eye using an image capture device and calculating, via the ECU, a motion profile of the lens capsule using the images. In addition, the method includes extracting, via the ECU, time-normalized lens capsule oscillation trajectories based on the motion profile, and then model fitting, via the ECU, the lens capsule oscillation trajectories to assess the lens capsule instability condition. Also disclosed herein is an automated system for performing embodiments of the method, the automated system comprising an energy source, an image capture device, and an ECU.

Inventors

  • J. A. Camping
  • M. Gruendig
  • A. HAUPT
  • M.A. Zilke
  • PETTIT GEORGE H.

Assignees

  • 爱尔康公司

Dates

Publication Date
20260512
Application Date
20211021
Priority Date
20201222

Claims (15)

  1. 1. A method for assessing a lens capsule stability condition in an eye of a human patient, the method comprising: directing electromagnetic energy in a predetermined spectrum onto a pupil of the eye via an energy source simultaneously after movement of the eye causes an eye saccade to occur therein; Acquiring an image of the eye indicative of the saccade using an image capturing device; calculating, via an electronic control unit ECU, a motion curve describing the motion of the lens capsule using the images; extracting a time-normalized lens capsule oscillation trace based on the motion profile via the ECU, and The time-normalized lens capsule oscillation trajectory is model fitted via the ECU to assess the lens capsule instability condition.
  2. 2. The method of claim 1, wherein calculating the motion profile comprises calculating a position profile, an instantaneous velocity profile, and/or an acceleration profile.
  3. 3. The method of claim 2, wherein the electromagnetic energy is light energy, the energy source is a light source, and the image capture device is a camera, and wherein acquiring an image of the eye comprises acquiring an image of a characteristic purkinje reflection within the eye.
  4. 4. The method of claim 3, wherein the characteristic purkinje reflections include a P1 reflection having a P1 coordinate and a P4 reflection having a P4 coordinate, the method further comprising subtracting the P1 coordinate from the P4 coordinate via the ECU to correct for rotation of the eye.
  5. 5. The method of claim 3, wherein the characteristic purkinje reflection comprises a P1 reflection, and wherein calculating the motion profile comprises calculating a motion profile of the P1 reflection.
  6. 6. The method of claim 1, further comprising transmitting a dynamic gaze guidance cue to a visual target disposed along a line of sight of the eye, thereby inducing the eye saccade.
  7. 7. The method of claim 1, wherein the image capture device is a high speed camera, directing electromagnetic energy in the predetermined spectrum onto a pupil of the eye via the energy source comprises directing an infrared IR beam onto the pupil, and acquiring an image of the eye indicative of the saccade of the eye comprises directing reflected IR light from the eye toward the high speed camera using a hot mirror.
  8. 8. The method of claim 1, wherein directing electromagnetic energy in the predetermined spectrum onto a pupil of the eye comprises directly imaging the lens capsule using ultrasonic energy, and wherein acquiring an image of the eye indicative of the saccade of the eye comprises collecting an ultrasonic image of the lens capsule.
  9. 9. The method of claim 1, wherein model fitting the lens capsule oscillation trajectory comprises using a focused mass model of the saccadic actuation force of the eye.
  10. 10. The method of claim 1, further comprising: providing different adjustment requirements to the human patient via an optical lens while acquiring the image, and Performing the model fit to the lens capsule oscillation trajectory using a nonlinear concentrated mass model; Wherein assessing the lens capsule instability condition comprises detecting ciliary muscle activity of the eye.
  11. 11. An automated system for assessing a lens capsule instability condition in an eye of a human patient, the system comprising: an energy source configured to direct electromagnetic energy in a predetermined spectrum onto or into the eye while inducing a saccade of the eye; An image capture device configured to acquire an image of the eye indicative of the saccade of the eye, and An electronic control unit ECU in communication with the energy source and the image capture device, wherein the ECU is configured to: calculating a motion profile of the lens capsule using the images, wherein the motion profile describes motion of the lens capsule; Extracting a time-normalized lens oscillation trajectory based on the motion profile, and Model fitting is performed on the time-normalized lens oscillation trajectory to evaluate the lens capsule instability condition.
  12. 12. The automated system of claim 11, wherein the electromagnetic energy is light energy, the energy source is a light source, and the image capture device is a high-speed camera, and wherein the image is a characteristic purkinje reflected image within the eye.
  13. 13. The automated system of claim 12, wherein the characteristic purkinje reflections comprise a P1 reflection having a P1 coordinate and a P4 reflection having a P4 coordinate, wherein the ECU is configured to subtract the P1 coordinate from the P4 coordinate via the ECU to correct for rotation of the eye.
  14. 14. The automated system of claim 12, wherein the characteristic purkinje reflection comprises a P1 reflection, and wherein the ECU is configured to calculate the motion profile of one of the characteristic purkinje reflections by calculating an instantaneous velocity profile, an instantaneous acceleration profile, and/or an instantaneous position profile of the P1 reflection.
  15. 15. The automated system of claim 11, further comprising a visual target, wherein the ECU is configured to transmit a dynamic gaze guidance cue to the visual target to induce the saccade.

Description

Automated assessment of human lens capsule stability Background The present disclosure relates to automated methods and systems for non-invasively diagnosing or assessing potential lens capsule stability within an eye of a human patient. A non-limiting example lens stability condition that may be effectively diagnosed in accordance with the present teachings is Zonule Insufficiency (ZI). Additionally, the solutions described herein may be customized to evaluate candidate patients of an accommodating intraocular lens (aIOL) device, for example, during a pre-operative fitting procedure, when determining an optimal cataract surgery plan, or when evaluating the accommodation potential of a patient. Similarly, other pre-operative, post-operative, diagnostic or therapeutic procedures related to lens capsule stability or general ocular health may benefit from the present teachings. The lens of the human eye comprises a lens capsule, an epithelium and supporting fibers. The lens capsule is in particular a thin transparent membrane, the outer periphery of which is firmly attached to an elastic fibrous ring, known in the art as the Zinn's membrane/zonules (zonules of Zinn), or simply zonules. The ciliary muscles within the eye contract or relax during accommodation to act together with the zonules, which have the effect of changing the shape of the lens capsule. Thus, the zonules are beneficial for normal eye function by securing the lens capsule along the optical axis while properly accommodating various forces applied to the lens by the ciliary muscles. The ZI condition described above occurs when the suspension ligament is excessively elastic or "floppy". As a result, the attachment of the lens and capsular bag to the ciliary muscle may become less secure. Thus, during cataract surgery, lens replacement, or aIOL device implantation, the risk of certain complications for patients diagnosed with a ZI condition may increase. A surgeon operating on a ZI patient may attempt to mitigate the risk of the procedure by employing a balloon support device to stabilize the capsular bag, by performing a laser-based capsulorhexis, or by taking other precautions. The size of the zonules is on the order of tens of microns. The extremely small size and fully occluded position of the zonules behind the iris prevents effective direct optical inspection of the structural integrity of the zonules. Thus, the presence of a ZI condition in a given patient is often indirectly revealed, for example, using a slit lamp examination, during which the surgeon applies a stimulus to the patient's body to initiate eye movement. For example, the clinician may tap a headrest supporting the patient's head to apply manual stimulation, or may lightly tap the patient's head side directly. Ultrasound stimulation may be used in alternative methods. The use of both methods may lead to increased anxiety in the patient, as the patient can anticipate the arrival of the stimulus. In particular, ultrasonic stimulation typically requires that the ultrasonic measurement device be in direct contact with the patient's eye. Furthermore, diagnostic results tend to be highly skill dependent and subjective. Thus, potential ZI conditions or other lens capsule instability conditions may be unexpectedly discovered, for example, during eye surgery, which may adversely affect the outcome of the surgery or require a change in the surgical plan. Disclosure of Invention Disclosed herein are methods and systems for performing automated evaluation of the structural integrity of a human eye lens capsule. The present teachings can be used to detect potential lens capsule instability conditions that may be indicative of a potential lens or lens capsule dislocation. By way of example and not limitation, the present teachings may be applied to assess zonule conditions and/or the potential of a patient for an accommodating intraocular lens or another surgical procedure. The method includes measuring and quantifying lens oscillations in accurately and reproducibly diagnosing such conditions. Embodiments of a method for assessing a lens capsule instability condition include directing electromagnetic energy in a predetermined spectrum onto a pupil of an eye via an energy source simultaneously after movement of the eye causes an eye saccade to occur therein. The method includes acquiring images of an eye indicative of saccades of the eye using an image capture device, and thereafter using the images via an Electronic Control Unit (ECU) to calculate a motion profile of the lens capsule. The method further includes extracting, via the ECU, a time-normalized lens capsule oscillation trajectory based on the curve, and then model fitting, via the ECU, the lens capsule oscillation trajectory to assess the lens capsule instability condition. An alternative embodiment of the method may include transmitting a dynamic gaze guidance cue to a visual target, wherein the visual target is disposed along