Scanning Ophthalmoscopes

A scanning ophthalmoscope for scanning the retina of an eye comprising:

• a source of collimated light:
• a first scanning element;
• a second scanning element;
• a scan relay device having two foci;
• wherein the source of collimated light, the first and second scanning elements and the scan relay device combine to provide a two-dimensional collimated light scan from an apparent point source;
• and
• the scanning ophthalmoscope further comprises a scan transfer device, wherein the scan transfer device has two foci and at least one vertex and the apparent point source is provided at a first focus of the scan transfer device and an eye is accommodated at a second focus of the scan transfer device, and wherein the scan transfer device transfers the two-dimensional collimated light scan from the apparent point source into the eye, and
• wherein the two foci of the scan relay device and the two foci of the scan transfer device define a first plane and the two foci and the at least one vertex of the scan transfer device define a second plane and wherein the first and second planes are substantially parallel.

A method of scanning the retina of an eye comprising the steps of:

• providing a source of collimated light, a first scanning element, a second scanning element and a scan relay device, wherein the scan relay device has two foci;
• using the source of collimated light, the first and second scanning elements and the scan relay device in combination to provide a two-dimensional collimated light scan from an apparent point source;
• providing a scan transfer device having two foci and at least one vertex;
• providing the apparent point source at a first focus of the scan transfer device and accommodating the eye at the second focus of the scan transfer device;
• using the scan transfer device to transfer the two-dimensional collimated light scan from the apparent point source to the eye, and
• wherein the two foci of the scan relay device, and the two foci of the scan transfer device define a first plane and the two foci and the at least one vertex of the scan transfer device define a second plane and the first and second planes are substantially parallel.

A scanning ophthalmoscope for scanning the retina of an eye comprising:

• a source of collimated light;
• a first scanning element:
• a second scanning element;
• a scan relay device;
• wherein the source of collimated light, the first and second scanning elements and the scan relay device combine to provide a two-dimensional collimated light scan from an apparent point source;
• and
• the scanning ophthalmoscope further comprises a scan transfer device, wherein the scan transfer device has two foci and the apparent point source is provided at a first focus of the scan transfer device and an eye is accommodated at a second focus of the Sean transfer device, and wherein the scan transfer device transfers the two-dimensional collimated light scan from the apparent point source into the eye,
• wherein the rotational axis of the second scanning element is substantially perpendicular to a line joining the two foci of the scan transfer device, and
• wherein, in the provision of the two-dimensional collimated light scan from the apparent point source, the scan relay device produces a one-dimensional collimated light scan, and the line joining the two foci of the scan transfer device is substantially perpendicular to a plane defined by the one-dimensional collimated light scan produced by the scan relay device.

A method of scanning the retina of an eye comprising the steps of:

• providing a source of collimated light, a first scanning element, a second scanning element and a scan relay device;
• using the source of collimated light, the first and second scanning elements and the scan relay device in combination to provide a two-dimensional collimated light scan from an apparent point source;
• providing a scan transfer device having two foci;
• positioning the second scanning element such that its rotational axis is substantially perpendicular to a line joining the two foci of the scan transfer device;
• providing the apparent point source at a first focus of the scan transfer device and accommodating the eye at the second focus of the scan transfer device;
• using the scan transfer device to transfer the two-dimensional collimated light scan from the apparent point source to the eye,
• wherein in the provision of the two-dimensional collimated light scan from the apparent point source, the scan relay device produces a one-dimensional collimated light scan, and the line joining the two foci of the scan transfer device is substantially perpendicular to a plane defined by the one-dimensional collimated light scan produced by the scan relay device.