Apparatus for visualizing the eye's tear film
First Claim
1. An ophthalmic instrument for imaging an eye'"'"'s tear film which covers the cornea, said ophthalmic instrument comprising:
- an illumination source;
means for directing along an illumination optical axis illumination to the outer surface of said tear film, wherein the aperture stop of the ophthalmic instrument is located along the illumination optical axis before the illumination reaches the tear film such that the illumination reaching the tear film is substantially independent of the shape of the tear film;
an imaging sensor;
means for directing along a collection optical axis the light reflected from the outer surface of the tear film onto said imaging sensor, whereby disruptions in the tear film are observed as localized intensity variations due to changes in image magnification resulting from corresponding thickness variations in the tear film.
5 Assignments
0 Petitions
Accused Products
Abstract
A technique for evaluating the topography of a cornea is disclosed, which utilizes a virtual image/object of a keratoscope pattern. The disclosed topography system includes a structured light source to create the keratoscope pattern or another diagnostic pattern, an optical assembly to focus the created pattern upon or behind the cornea, and for capturing the image reflected off the patient'"'"'s eye and directing the reflected image toward an imaging system for processing. Light emitted by the light source is preferably not in the visible range, to minimize discomfort to the patient. Since the topography is evaluated with a projected virtual image, there is no nose or brow shadow, thereby allowing better corneal coverage. The optical system includes an aperture stop which is preferably conjugate with a point behind the corneal surface approximating the center of a normal cornea. Thus, wide angle capture is achieved as reflected rays reaching the imaging system appear as if they originated at the center of the cornea. A pupil detection mechanism is disclosed which is performed independently of the diagnostic pattern illumination, thereby facilitating pupil detection. In an alternate embodiment, the diagnostic pattern is generated using a variable light pattern generator, which provides flexibility in selecting target images to achieve various diagnostic abilities. The disclosed topography system may be used as a visual field measuring device, a perimeter, or an instrument for visualizing abnormalities in the eye'"'"'s tear film.
-
Citations
21 Claims
-
1. An ophthalmic instrument for imaging an eye'"'"'s tear film which covers the cornea, said ophthalmic instrument comprising:
-
an illumination source;
means for directing along an illumination optical axis illumination to the outer surface of said tear film, wherein the aperture stop of the ophthalmic instrument is located along the illumination optical axis before the illumination reaches the tear film such that the illumination reaching the tear film is substantially independent of the shape of the tear film;
an imaging sensor;
means for directing along a collection optical axis the light reflected from the outer surface of the tear film onto said imaging sensor, whereby disruptions in the tear film are observed as localized intensity variations due to changes in image magnification resulting from corresponding thickness variations in the tear film. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. An ophthalmic instrument for imaging an eye'"'"'s tear film which covers the cornea, said ophthalmic instrument comprising:
-
a light source;
an imaging sensor;
an optical lens system having an aperture stop;
a beam splitter for directing along an illumination optical axis illumination through said optical lens system which focuses the illumination to a point behind the cornea, and also forms a virtual object of said aperture stop at or near the nominal center of curvature of said cornea, said optical lens system collecting along a collection optical axis light reflected from the outer surface of the tear film and passing the reflected light to said beam splitter which focuses said reflected light onto said imaging sensor, whereby disruptions in the tear film are observed as localized intensity variations due to changes in image magnification resulting from corresponding thickness variations in the tear film. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
-
Specification
-
- Resources
-
Current AssigneeVisionrx, LLC
-
Original AssigneeVisionRx, Inc.
-
InventorsMaloney, Robert K., Truax, Bruce E., Stewart, Jeffrey L.
-
Primary Examiner(s)MANUEL, GEORGE C
-
Application NumberUS09/498,803Time in Patent Office946 DaysField of Search351/200, 351/205, 351/206, 351/208, 351/211, 351/212, 351/221, 351/246, 351/247, 606/4, 606/5US Class Current351/212CPC Class CodesA61B 3/101 for examining the tear filmA61B 3/107 for determining the shape o...
