Ophthalmic surgical microscope

Patent metadata

Field	Value
Publication number	US-11147447-B2
Application number	US-201916526971-A
Country	US
Kind code	B2
Filing date	Jul 30, 2019
Priority date	Jul 30, 2018
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

An ophthalmic surgical microscope includes a main objective lens, through which an observation beam path passes, and a confocal optical system configured as a refractometer to determine the refraction of an eye. The optical system includes a measurement light source to generate a measurement light beam, a light detector to measure an intensity of measurement light and an optical unit to direct the measurement light beam onto the retina of the eye and to return measurement light reflected back at the retina to the light detector. The optical system includes an adaptive optical module (AOM) to modify a wavefront of the measurement beam path such that an intensity of the back-reflected measurement light changes. A spherical equivalent (SE) of the ametropia of the eye is determined based on a setting of the AOM, at which the measured intensity of the back-reflected measurement light has a maximum.

First claim

What is claimed is:

1. An ophthalmic surgical microscope, comprising:
a main objective lens through which an observation beam path passes;
a confocal optical system configured as a refractometer to determine a refraction of an eye of a patient and including:
a measurement light source to generate a measurement light beam;
a measuring module including a light detector to measure an intensity of measurement light; and
an optical unit through which a measurement beam path passes to direct the measurement light beam onto a retina of the eye of the patient and to return back-reflected measurement light reflected back at the retina to the light detector, the measurement beam path being confocal over an entire range of the measurement beam path, the optical unit including an adaptive optical module (AOM), a wavefront of the measurement beam path being modifiable by adjusting the AOM such that an intensity of the back-reflected measurement light measured by the light detector changes;

the measuring module being configured to determine a spherical equivalent of an ametropia of the eye based on a setting of the AOM, at which the intensity of the back-reflected measurement light measured by the light detector has a maximum;
the AOM including an adaptive component configured to compensate an astigmatism in the wavefront of the measurement beam path by adjusting the adaptive component; and
the measuring module being configured to determine the astigmatism of the eye and an axis position of the astigmatism from a setting of the adaptive component at which the measured intensity of the back-reflected measurement light has the maximum.

2. The ophthalmic surgical microscope as claimed in claim 1 , wherein the adaptive component is adjustable to a neutral setting, in which the adaptive component has no astigmatic power or substantially no astigmatic power.

3. The ophthalmic surgical microscope as claimed in claim 1 , wherein:
the adaptive component includes two cylindrical lenses twistable relative to one another,
a first cylindrical lens of the two cylindrical lenses has a positive refractive power and a second cylindrical lens of the two cylindrical lenses has a negative refractive power,
the positive and the negative refractive powers are equal in terms of an absolute value.

4. The ophthalmic surgical microscope as claimed in claim 1 , wherein:
the adaptive component includes a first plate and a second plate,
the first plate has a first surface contour and the second plate has a second surface contour,
the first and second surface contours are complementary to one another, and
the first and second plates are displaceable in a translational fashion, twistable together, and/or twistable relative to one another.

5. The ophthalmic surgical microscope as claimed in claim 1 , wherein the adaptive component provides an adjustable spherical refractive power to compensate the spherical equivalent of the ametropia, and an adjustable astigmatic refractive power to compensate the astigmatism.

6. The ophthalmic surgical microscope as claimed in claim 1 , wherein the adaptive component is positioned in a plane that is conjugate to the plane of a pupil of the eye when the ophthalmic surgical microscope is being operated.

7. The ophthalmic surgical microscope as claimed in claim 1 , further comprising:
an optical fiber having a free end, the free end forming an emergence end for the measurement light beam and an entrance end for the back-reflected measurement light,
wherein the measurement light source and the light detector are connected to the optical fiber, and
wherein the emergence end and the entrance end are confocal.

8. The ophthalmic surgical microscope as claimed in claim 1 , further comprising:
a collimator arranged in the measurement beam path and being zoomable;
a lock-in amplifier arranged in the measurement beam path and including a chopper wheel; and
a deflection element arranged in the measurement beam path and periodically deflecting the measurement light beam to permit measurement light to be periodically moved on the retina of the eye when the ophthalmic surgical microscope is being operated.

9. The ophthalmic surgical microscope as claimed in claim 1 , wherein:
the AOM includes an afocal telescope which is adjustable to compensate the spherical equivalent of the ametropia of the eye,
the confocal optical system includes a control unit to adjust the AOM,
the control unit is configured to:
initially adjust the AOM during a neutral setting of the adaptive component, in which the adaptive component has no, or virtually no, astigmatic power, until the intensity measured at the light detector has the maximum, and
adjust the AOM such that the intensity of the back-reflected measurement light, as measured at the light detector, has the maximum.

10. The ophthalmic surgical microscope as claimed in claim 9 , wherein:
the optical unit includes a first optical arrangement, through which the measurement beam path passes and a second optical arrangement provided downstream of the first optical arrangement as seen from the measurement light source,
the adaptive component is arranged close to a measurement light source-side focal plane of the first optical arrangement, and.
the second optical arrangement converts the measurement beam path into a parallel beam path.

11. The ophthalmic surgical microscope as claimed in claim 1 , further comprising:
a separation mirror to separate the observation beam path from the measurement beam path, and
wherein the separation mirror is arranged upstream of the main objective lens as seen from the measurement light source and the measurement beam path passes through the main objective lens.

12. The ophthalmic surgical microscope as claimed in claim 11 , wherein the measurement beam path passes through the main objective lens in an off-centered fashion relative to an optical axis of the main objective lens.

13. The ophthalmic surgical microscope as claimed in claim 1 , further comprising:
an illumination beam path to illuminate an observation area, and
wherein the illumination beam path passes through a part of the optical unit of the confocal optical system.

14. The ophthalmic surgical microscope as claimed in claim 1 , wherein the confocal optical system is additionally configured as an optical coherence tomography (OTC) system to examine the eye by optical coherence tomography.

15. The ophthalmic surgical microscope as claimed in claim 14 , wherein:
the measurement light source is an OCT light source to perform a refraction measurement,
the light detector acts as an OCT detector,
an OCT beam path passes through optical elements of the optical unit to record an OCT scan, and
the measurement beam path passes through the optical elements to perform the refraction measurement through which the OCT beam path passes to record the OCT scan.

16. The ophthalmic surgical microscope as claimed in claim 15 , further comprising:
an optical element to switch between the refraction measurement and the recording of the OCT scan, wherein:
the optical element is arranged in the measurement beam path of the refraction measurement or into the OCT beam path to record the OCT scan, or
the optical element is removed from the measurement beam path of the refraction measurement or from the OCT beam path to record the OCT scan.

17. The ophthalmic surgical microscope as claimed in claim 15 , wherein:
the optical unit of the confocal optical system includes a scanning mirror arrangement including two scanning mirrors, and
at lea

Assignees

• Zeiss Carl Meditec Ag

Inventors

• Seesselberg Markus
• Hauger Christoph
• Hoegele Artur
• Steffen Joachim

Classifications

• A61B3/102

  for optical coherence tomography [OCT] · CPC title

• A61B3/13 Primary

  Ophthalmic microscopes · CPC title

• A61B3/103 Primary

  for determining refraction, e.g. refractometers, skiascopes · CPC title