Patent ID: 7530692
Filing Date: 2009-05-12
Classification: A61B

Abstract:
1. An ophthalmologic photographing apparatus, comprising: a light source section for emitting illumination light to illuminate a retina of an eye under measurement; an aberration measurement section for receiving a reflected light beam from the retina and measuring the aberrations of the eye under measurement; an aberration compensation section having a wavefront compensation element for compensating for the reflected light beam from the retina on the basis of the aberrations measured by the aberration measuring section so as to offset the aberrations; an illumination optical system that has a scanning mirror for scanning a part of the retina in a two-dimensional direction by the illumination light beam from the light source section and, illuminates the retina of the eye under measurement; a light-receiving optical system for receiving the reflected light beam that is illuminated through a path including the scanning mirror, reflected from the retina and compensated in aberrations by the aberration compensation section; a photodetector for receiving the light beam from the light-receiving optical system; an image forming section for forming a retinal image according to a scan position of the scanning mirror and a light-reception signal of the photodetector; and a calculation section for estimating a blood flow rate of a blood vessel on the retina, wherein the wavefront compensation element faces the scanning mirror, the scanning mirror and the wavefront compensation element are disposed at pupil-conjugated positions or at substantially pupil-conjugated positions, the scanning mirror scans the retina on a circular orbit or rotational orbit at plural times, the photodetector accumulates received light while one half of the circular orbit or rotational orbit is scanned, outputs an accumulated first light amount, accumulates received light while the other half of the circular orbit or rotational orbit is scanned and, outputs an accumulated second light amount, and the calculation section stores the first light amount in association with the time, stores the second light amount in association with the time, calculates the time difference between the peak of the first light amount and the peak of the second light amount on the basis of the time variation of the first light amount and the time variation of the second light amount, and divides the diameter of the circular orbit or the diameter of the rotational orbit by the calculated time difference to thereby estimate the blood flow rate, further wherein the calculation section shifts the waveform corresponding to the time variation of the first light amount and the waveform corresponding to the time variation of the second light amount in the time-axial direction to calculate a time shift amount at which both the waveforms are most remarkably overlapped with each other, and sets the time shift amount as the time difference between the peak of the first light amount and the peak of the second light amount.