Abstract: A laser scanning system adapted to produce a scanned image including a number of lines of an object. A method includes the steps of providing a reference object arranged such that the scanned image produced by the laser scanning system includes a reference image of the reference object, processing the reference image to calculate an error arising from non-repeatable displacement of the lines of the reference image, and adjusting at least one operating parameter of the laser scanning system in response to the calculated error.

Abstract: The invention provides a method of reducing jitter error in a laser scanning system (1) adapted to produce a scanned image comprising a number of lines of an object (18). The method comprising the steps of providing a reference object (22) arranged such that the scanned image produced by the laser scanning system (1) includes a reference image (24) of the reference object (22); processing the reference image (24) to calculate an error arising from non-repeatable displacement of the lines of the reference image (24); and adjusting at least one operating parameter of the laser scanning system (1) in response to the calculated error.

Abstract: An embodiment of the invention provides an apparatus and a method. An intensity gradient between first and second optical image data of an optical image produced by an optical scanning device is determined. The first optical image data is a first optical image pixel and the second optical image data is a second optical image pixel. An intensity gradient image comprising a plurality of intensity gradient image pixels is determined, each intensity gradient image pixel representing the magnitude of an intensity gradient. One or more anomalies in the optical image in dependence on the magnitude of the intensity gradient being greater than or equal to a threshold value is identified.

Abstract: An image processing apparatus uses first and second digital vascular image data to register two images. The two images may be from different imaging modes. The first and second images are processed with a two-dimensional, directional filter (500) that has the effect of producing clusters of orthogonally adjacent image data points in which the magnitude of an intensity gradient between each orthogonally adjacent image data point is less than a predetermined value. Subsequently, common clusters are identified between the first and second image data using a corner detecting algorithm (600). The directional filter produces “stepping” features, where vascular features would otherwise appear with smooth edges. These numerous features are identified by the corner detecting algorithm and can be used (1000) for registering common clusters between the first and second image data. The filter may be a rotating Gabor filter matched to vascular features in the images.

Abstract: An alignment apparatus and method is disclosed, for ensuring correct alignment of a patient's eye with respect to an ophthalmic or optometric instrument. Graphical objects are provided which represent an ideal and an actual position of the eye, and provide for easy and intuitive feedback to an eye care professional operating the instrument on the alignment position of the patient.

Abstract: A method of identifying anomalies in images produced using an imaging device (70). The method comprises receiving (10), (12) first and second pluralities of candidate anomalies, the candidate anomalies being identified in subsequent images produced with an imaging device. A constellation match (14), (16), (18), (19) is carried out between the first and second pluralities of candidate anomalies to identify a correlation therebetween, represented by a constellation match value. A plurality of constellation match values is determined with a different relative x-y shift between the first and second pluralities of candidate images. If a good correlation is found at a particular x-y shift then the candidate anomalies are common between the first and second images, which is indicative of the first and second images including anomalies.

Abstract: A method of determining a geometrical measurement of a retina of an eye, comprising obtaining a two dimensional representation of at least a portion of the retina of the eye (34), deriving a geometrical remapping which converts the two dimensional representation of the retinal portion to a three dimensional representation of the retinal portion (36), using one or more coordinates of the two dimensional representation of the retinal portion to define the geometrical measurement to be taken of the retina on the two dimensional representation (38), using the geometrical remapping to convert the or each coordinate of the two dimensional representation of the retinal portion to an equivalent coordinate of the three dimensional representation of the retinal portion (40), and using the or each equivalent coordinate of the three dimensional representation of the retinal portion to determine the geometrical measurement of the retina of the eye (42).

Abstract: A scanning laser ophthalmoscope for scanning the retina of an eye is provided comprising a light source emitting a beam of light, scan relay elements, wherein the light source and the scan relay elements provide a two-dimensional scan of the light beam which is transferred from an apparent point source at a pupillary point of the eye to the retina of the eye, and a static aberration correction element (30) which has a shape defined to provide correction of aberrations of at least some of the scan relay elements and a location within the ophthalmoscope chosen to provide correction of aberrations of at least some of the scan relay elements, which location maintains transfer of the beam of light from the apparent point source at the pupillary point of the eye to the retina of the eye. The present solution further provides an aberration correction element and a method of determining a shape of the aberration correction element.

Abstract: A method of determining a correction for distortion in eye representations of an ophthalmoscope comprising (i) constructing an optical description of a system comprising the ophthalmoscope and a model eye, (ii) passing a ray through the system onto a surface of the model eye, (iii) calculating an actual measurement of the ray at the surface, (iv) determining a horizontal scanning angle and a vertical scanning angle of the system for the ray, (v) calculating an expected measurement of the ray at the surface using the horizontal scanning angle and vertical scanning angle of the system, (vi) repeating steps (ii) to (v) for a plurality of further rays, and (vii) comparing the actual measurements of the rays at the surface with corresponding expected measurements of the rays at the surface to determine the correction for distortion in eye representations of the ophthalmoscope.

Abstract: An embodiment of the invention provides an apparatus and a method. An intensity gradient between first and second optical image data of an optical image produced by an optical scanning device is determined. The first optical image data is a first optical image pixel and the second optical image data is a second optical image pixel. An intensity gradient image comprising a plurality of intensity gradient image pixels is determined, each intensity gradient image pixel representing the magnitude of an intensity gradient. One or more anomalies in the optical image in dependence on the magnitude of the intensity gradient being greater than or equal to a threshold value is identified.

Abstract: A method of performing a retinal examination is described wherein perimetry points are selected in three dimensional imaging data of the retinal tissue. The corresponding points in register with these perimetry points are mapped to an en-face image. These corresponding points are used as stimulus locations for a micro-perimetry examination.

Abstract: Apparatus for illuminating the retina of an eye. The apparatus comprising an illumination device, a lens system, wherein the illumination device and the lens system combine to provide incident illumination from an apparent point source located within the lens system. The apparatus further comprising an illumination transfer device, wherein the illumination transfer device has two foci and the apparent point source of the lens system is provided at a first focus point of the illumination transfer device and an eye is accommodated at a second focus point of the illumination transfer device, and wherein the illumination transfer device transfers the incident illumination from the apparent point source into the eye to illuminate the retina.

Abstract: A method of identifying anomalies in images produced using an imaging device (70). The method comprises receiving (10), (12) first and second pluralities of candidate anomalies, the candidate anomalies being identified in subsequent images produced with an imaging device. A constellation match (14), (16), (18), (19) is carried out between the first and second pluralities of candidate anomalies to identify a correlation therebetween, represented by a constellation match value. A plurality of constellation match values is determined with a different relative x-y shift between the first and second pluralities of candidate images. If a good correlation is found at a particular x-y shift then the candidate anomalies are common between the first and second images, which is indicative of the first and second images including anomalies.

Abstract: The invention provides an apparatus and method for scanning, imaging and treating the retina of an eye. The apparatus (10) comprises a source of collimated light (14), a two-dimensional scanning device (16) having two axes of rotation (16a, 16b), wherein the axes of rotation (16a, 16b) are orthogonal and substantially planar, and wherein the source of collimated light (14) and the two-dimensional scanning device (16) combine to provide a two-dimensional collimated light scan from a point source (22). The apparatus (10) further comprises a scan transfer device (18), wherein the scan transfer device (18) has two foci (18a, 18b) and the point source (22) is provided at a first focus point (18a) of the scan transfer device (18) and an eye (12) is accommodated at a second focus point (18b) of the scan transfer device (18), and wherein the scan transfer device (18) transfers the two-dimensional collimated light scan from the point source (22) into the eye (12).

Abstract: The invention provides an apparatus and method for illuminating, imaging and treating the retina of an eye. The apparatus (10) comprises at least one light source (16), wherein the at least one light source (16) is adapted to provide collimated light (20) from a plurality of point sources (22), and wherein each point source (22) lies on an arc (18), and wherein the at least one light source (16) is configured to direct collimated light (20) from each point source (22) along the radius (24) of the arc (18) towards a centre point (26) of the arc (18), and wherein, in use, the apparatus (10) is arranged such that the centre point (26) of the arc (18) is substantially coincident with the pupillary point (40) of the eye (14), such that collimated light (20) is transmitted from the point source through the pupillary point (40) of the eye (14) to illuminate the retina (12).

Abstract: The invention provides an apparatus and method for illuminating, imaging and treating the retina of an eye. The apparatus (10) comprises an illuminating device (16) including a planar light source capable of producing light in a plane, such that the illuminating device (16) is capable of illuminating a circumferential line on the retina (12) and a support structure, wherein the illuminating device (16) is pivotably mountable to the support structure and is rotatable about an axis (18) which lies substantially on the plane defined by the light source, such that, in use, the illuminating device (16) may be rotated about the axis (18) to illuminate an area of the retina (12).

Abstract: A method of performing spectral OCT imaging on a target involves repeatedly scanning said target along a transverse scanning line with an object beam derived from an OCT interferometer having a narrowband source. The wavelength of the narrowband source is modulated over a range of wavelengths at a rate that is slow relative to the rate of scanning the target. The object beam returned from the target is detected to produce a set of data obtained from multiple scans along said scanning line over the entire range of wavelengths. The data is then processed to extract an OCT image (typically a B-scan) of the target containing depth information.

Abstract: A method and apparatus of producing a three-dimensional image of at least a part of the retina of an eye is provided. The method including obtaining a two-dimensional wide-field image of said part of said retina, determining a three-dimensional shape for said part of said retina and using the three-dimensional shape for said part of said retina to modify said two-dimensional image to produce a three-dimensional image of said part of said retina. The apparatus including an imaging system adapted to provide a two-dimensional wide-field image of said part of said retina, a three-dimensional shape determination module adapted to determine a three-dimensional shape for said part of said retina, and a two-dimensional image modification module adapted to modify said two-dimensional wide-field image of said part of said retina using said three-dimensional shape to produce a three-dimensional image of said part of said retina.

Abstract: An optical coherence tomography (OCT) apparatus includes an optical source, an interferometer generating an object beam and a reference beam, a transverse scanner for scanning an object with said object beam, and a processor for generating an OCT image from an OCT signal returned by said interferometer. At least the optical source, the interferometer, and the scanner are mounted on a common translation stage displaceable towards and away from said object. A dynamic focus solution is provided when the scanner and a folded object path are placed on the translation stage.

Abstract: A diagnostic method is disclosed wherein the potential preserved visual acuity in the retina of a patient is determined from the amount of tissue connecting the inner and outer plexiform layers remaining in the retina.