Method and apparatus for optical coherence tomographic fundus imaging without vignetting

Apparatus, including a fundus camera, for illuminating the fundus of an eye with a beam of radiation output from a beam scanner, the apparatus comprises:

• means for transferring radiation from the output beam of radiation, including chief rays of the output beam of radiation which emerge from a point of final deflection of the beam scanner;
• and
• means for focusing the transferred radiation so that the output beam of radiation is focused onto the fundus of the eye;
• wherein the means for transferring comprises an internal focusing lens means of the fundus camera wherein the internal focusing lens means is fixed with respect to the beam scanner so that the point of final deflection is located substantially in the back focal plane of the internal focusing lens means and wherein the internal focusing lens means is movable.

Apparatus for use in optical coherence tomography which includes a Doppler shifter, the Doppler shifter comprising:

• means for splitting a beam into a reference beam and a sample beam;
• a rotatable, refractive, light transmissive block, the block having four substantially equal length sides formed into a square;
• means for rotating the block;
• means for directing the reference beam to impinge on the block in a reference direction and means for directing the sample beam to impinge upon the block in a sample direction, the reference direction and the sample direction being disposed substantially at a 45 degree angle with respect to each other;
• and
• a first and a second reflecting means disposed behind the block to reflect the reference beam and the sample beam emerging therethrough back through the block.

Method for illuminating the fundus of an eye with a beam of radiation output from a beam scanner, the method comprises the steps of:

• transferring radiation from the output beam of radiation, including chief rays of the output beam of radiation which emerge from a point of final deflection of the beam scanner;
• and
• focusing the transferred radiation so that the output beam of radiation is focused onto the fundus of the eye;
• wherein the step of transferring comprises transferring with a movable lens which is fixed with respect to the beam scanner so that the point of final deflection is located substantially in the back focal plane of the lens.

Method for illuminating the fundus of an eye with a beam of radiation output from a beam scanner, the method comprises the steps of:

• transferring radiation from the output beam of radiation, including chief rays of the beam of radiation which emerge from a point of final deflection of the beam scanner;
• and
• focusing the transferred radiation so that the output beam of radiation is focused onto the fundus of the eye;
• wherein the step of transferring comprises transferring with a beamsplitter which is fixed with respect to the beam scanner and a movable focusing lens so that the point of final deflection is located substantially in the back focal plane of the focusing lens.