Device and method for ophthalmologically treating the eye using a fixation light beam
A device for ophthalmologically treating the eye has a treatment laser beam (UV) for ablating parts of the cornea ( 12 ) and a fixation light beam ( 24 ). A fixation light spot in the vicinity of the fovea ( 30 ) and the fovea are imaged by means of a camera ( 40 ). This makes it possible to check whether the patient has reliably fixated the fixation light source ( 22 ). In addition, the pupil can be recorded and both recordings can be superimposed.
1. An ophthalmological apparatus, comprising:
a laser for providing a laser beam for treating a cornea of an eye of a patient;
a fixation light source for emitting a fixation light beam at a visible wavelength, the fixation light beam provided for visual fixation by the patient;
a first camera adapted for focusing on a retinal plane of the eye to capture a first image showing a retinal area including a fovea of the eye, wherein the first camera is positioned to receive a portion of the fixation light beam reflected from the retina of the eye so that the first image includes a visible light spot generated by the fixation light beam on the retina;
a computer performing an evaluation function for determining from the first image whether the light spot is sufficiently precise on the fovea to determine if the patient properly fixates the fixation light beam with the eye;
a second camera focused on a plane of a pupil of the eye for capturing a second image showing the pupil;
wherein the computer performs a superimposing function for superimposing the first and second images to allow a determination of a positional relationship of the light spot and fovea with respect to the pupil.
2. An ophthalmological apparatus, comprising:
a laser for providing a laser beam for treating a cornea of an eye of a patient;
a fixation light source for emitting a fixation light beam at a visible wavelength, the fixation light beam provided for visual fixation by the patient;
a first camera adapted for focusing on a retinal plane of the eye to capture a first image showing a retinal area including a fovea of the eye, wherein the first camera is positioned to receive a portion of the fixation light beam reflected from the retina of the eye so that the first image includes a visible light spot generated by the fixation light beam on the retina;
a computer performing an evaluation function for determining from the first image whether the light spot is sufficiently precise on the fovea to determine if the patient properly fixates the fixation light beam with the eye;
wherein the first camera is adapted to zoom between the retinal plane and a pupil plane of the eye to selectively capture the first image and a second image showing the pupil base based on a zooming state of the first camera.
3. The apparatus according to claim 2 , wherein the computer performs a superimposing function for superimposing the first and second images to allow a determination of a positional relationship of the light spot and fovea with respect to the pupil.
4. An ophthalmological apparatus, comprising:
a laser for providing a laser beam for treating a cornea of an eye of a patient;
a fixation light source for emitting a fixation light beam at a visible wavelength, the fixation light beam provided for visual fixation by the patient;
a first camera adapted for focusing on a retinal plane of the eye to capture a first image showing a retinal area including a fovea of the eye, wherein the first camera is positioned to receive a portion of the fixation light beam reflected from the retina of the eye so that the first image includes a visible light spot generated by the fixation light beam on the retina;
a computer performing an evaluation function for determining from the first image whether the light spot is sufficiently precise on the fovea to determine if the patient properly fixates the fixation light beam with the eye and performing an image processing function for processing the first image to calculate an ablation center as a center point of the light spot and the fovea; and
a control unit for controlling the laser such as to move the laser beam across a cornea of the eye in a centered manner with respect to the calculated ablation center.
5. An ophthalmological method, comprising:
providing a laser beam for treating a cornea of an eye of a patient;
emitting a fixation light beam at a visible wavelength, the fixation light beam provided for visual fixation by the patient;
capturing, by using a first camera focused on a retinal plane of the eye, a first image showing a retinal area including a fovea of the eye, the first image including a visible light spot generated by the fixation light beam on the retina;
determining from the first image whether the light spot is sufficiently precise on the fovea to determine if the patient properly fixates the fixation light beam with the eye;
capturing, by using a second camera focused on a plane of a pupil of the eye, a second image showing the pupil; and
superimposing the first and second images to allow a determination of a positional relationship of the light spot and fovea with respect to the pupil.
6. An ophthalmological method, comprising:
providing a laser beam for treating a cornea of an eye of a patient;
emitting a fixation light beam at a visible wavelength, the fixation light beam provided for visual fixation by the patient;
capturing, by using a first camera focused on a retinal plane of the eye, a first image showing a retinal area including a fovea of the eye, the first image including a visible light spot generated by the fixation light beam on the retina;
determining from the first image whether the light spot is sufficiently precise on the fovea to determine if the patient properly fixates the fixation light beam with the eye;
zooming the first camera between the retinal plane and a pupil plane of the eye to selectively capture the first image and a second image showing the pupil based on a zooming state of the first camera.
7. The method according to claim 6 , further comprising:
superimposing the first and second images to allow a determination of a positional relationship of the light spot and fovea with respect to the pupil.
8. An ophthalmological method, comprising:
providing a laser beam for treating a cornea of an eye of a patient;
emitting a fixation light beam at a visible wavelength, the fixation light beam provided for visual fixation by the patient;
capturing, by using a first camera focused on a retinal plane of the eye, a first image showing a retinal area including a fovea of the eye, the first image including a visible light spot generated by the fixation light beam on the retina;
determining from the first image whether the light spot is sufficiently precise on the fovea to determine if the patient properly fixates the fixation light beam with the eye;
processing the first image to calculate an ablation center as a center point of the light spot and the fovea; and
controlling the laser such as to move the laser beam across a cornea of the eye in a centered manner with respect to the calculated ablation center.