CORNEAL SURGERY APPARATUS

• US 20100057059A1
• Filed: 11/29/2007
• Published: 03/04/2010
• Est. Priority Date: 11/29/2006
• Status: Active Grant

• Current Assignee: Nidek Company Limited
• Original Assignee: Nidek Company Limited
• Inventors: Makino, Hirokatsu
• Granted Patent: US 8,523,846 B2
• Time in Patent Office: Days
• US Class Current: 606/4
• CPC Class Codes: A61B 3/113 for determining or recording eye movement
• CPC Class Codes: A61F 2009/00846 Eyetracking
• CPC Class Codes: A61F 2009/00872 Cornea
• CPC Class Codes: A61F 9/00804 Refractive treatments
• CPC Class Codes: A61F 9/00814 Laser features or special beam parameters therefor

Abstract

A corneal surgery apparatus which comprises a laser irradiation optical system and an eye position change detection unit comprising an illumination optical system and an image pick-up camera picking up an anterior-segment image of a patient'"'"'s eye and detecting the change in eye position based on an iris pattern in the image, and is arranged such that an irradiation position tracks movement of the eye to ablate a cornea, wherein the apparatus further comprises a contrast adjustment unit extracting a pupil portion and an iris portion based on luminance information of the image, and increasing/decreasing a set value of an illumination light amount and/or a set value of a gain of the camera to increase a contrast of the pupil portion to the iris portion and/or a contrast of the iris pattern within a range that luminance at the iris portion is not saturated.

Claims

1. A corneal surgery apparatus, which comprises:

a laser irradiation optical system capable of changing an irradiation position with a laser beam emitted from a laser source on a cornea of a patient'"'"'s eye; and

an eye position change detection unit, which comprises;

an illumination optical system arranged to illuminate an anterior segment of the patient'"'"'s eye;

and

an image pick-up camera arranged to pick up an image of the anterior segment illuminated by the illumination optical system,

and is arranged to detect change in eye position including torsion of an eyeball of the patient'"'"'s eye subjected to a surgical operation based on an iris pattern in the anterior-segment image picked up with the image pick-up camera,

and is arranged such that the irradiation position with the laser beam which is applied by the laser irradiation optical system tracks movement of the patient'"'"'s eye based on a result of the detection by the eye position change detection unit, and the cornea is ablated to a desired shape by the application of the laser beam,

wherein the corneal surgery apparatus further comprises a contrast adjustment unit arranged to extract a pupil portion and an iris portion based on luminance information on the anterior-segment image picked up with the image pick-up camera, and increase and decrease at least one of a set value of an illumination light amount of the illumination optical system and a set value of a gain of the image pick-up camera so as to increase at least one of a contrast of the pupil portion with respect to the iris portion and a contrast of the iris pattern within a range such that luminance at the iris portion is not saturated.

2. The corneal surgery apparatus according to claim 1, wherein the contrast adjustment unit is arranged to extract the pupil portion and the iris portion based on the luminance information on the anterior-segment image picked up with the image pick-up camera each time at least one of the set value of the illumination light amount of the illumination optical system and the set value of the gain of the image pick-up camera is increasingly or decreasingly changed, and adjust the set value so that at least one of a difference between luminance at the extracted iris portion and luminance at the extracted pupil portion and a difference in luminance in the iris pattern is maximized or exceeds a predetermined reference value.

3. A corneal surgery apparatus, which comprises:

a laser irradiation optical system capable of changing an irradiation position with a laser beam emitted from a laser source on a cornea of a patient'"'"'s eye; and

an eye position change detection unit, which comprises;

an illumination optical system arranged to illuminate an anterior segment of the patient'"'"'s eye;

and

an image pick-up camera arranged to pick up an image of the anterior segment illuminated by the illumination optical system,

and is arranged to detect change in eye position including torsion of an eyeball of the patient'"'"'s eye subjected to a surgical operation based on an iris pattern in the anterior-segment image picked up with the image pick-up camera,

and is arranged such that the irradiation position with the laser beam which is applied by the laser irradiation optical system tracks movement of the patient'"'"'s eye based on a result of the detection by the eye position change detection unit, and the cornea is ablated to a desired shape by the application of the laser beam,

wherein the corneal surgery apparatus further comprises;

a projection optical system arranged to project a visible light beam onto the patient'"'"'s eye; and

a setting unit arranged to set an allowable range of variation of a pupil size such that the iris pattern is detectable with respect to a pupil size at the time when the iris pattern used as a reference for the change in eye position is obtained by the eye position change detection unit, and further comprises;

a display control unit comprising a display unit arranged to display the anterior-segment image picked up with the image pick-up camera, and is arranged to display a guide mark indicating the allowable range of the variation of the pupil size which is set based on a pupil center of the anterior-segment image by the setting unit in a manner of being superimposed on the anterior-segment image displayed on the display unit; and

a light-amount adjustment unit comprising an operation switch with which a light amount of the projection optical system is changed manually, or further comprises;

a light-amount adjustment unit arranged to determine whether or not the pupil size detected by the eye position detection unit goes beyond the allowable range of the variation of the pupil size set by the setting unit, and automatically adjust the light amount of the projection optical system based on a result of the determination.