JP2009000354A5 - - Google Patents

Claims (4)

Input means for inputting at least one of a fundus image captured by a fundus imaging apparatus including an imaging optical system in which an image sensor is arranged and optical characteristics information of a subject's eye, diopter, axial length, and corneal curvature. An ophthalmologic measurement apparatus that measures an actual distance on the fundus based on the input information,
Storage means for storing a scale variable C (α) of the imaging optical system related to the diopter of the subject's eye, which is independent of optical characteristics other than the diopter of the subject's eye ;
The imaging magnification β of the fundus image of the subject's eye obtained by the fundus imaging apparatus is defined as the scale variable C (α) and the distance (object distance) d from the fundus side principal point of the subject's eye to the fundus. calculating means for calculating the actual distance on the fundus of the eye fundus image in search, based on the imaging magnification β determined based on,
With
The computing means obtains the object distance d based on an imaging relational expression related to the object distance d derived from a predetermined eyeball optical system model and optical characteristic information inputted by the input means. Ophthalmic measuring device. The ophthalmic measurement device according to claim 1.
  The scale variable is
    A plurality of types of eye models having indices on the fundus and having different diopters are photographed for each diopter by the photographing optical system, and the photographing magnification obtained from the photographed indices is used as an index of the eye model. It is a function of diopter obtained by dividing by the distance from the object side principal point of the eye model to the index determined for each diopter when it is a point,
An ophthalmologic measuring apparatus characterized by that. In the ophthalmic measurement apparatus according to claim 1 or 2,
  The relational expression of imaging with respect to the object distance d is
    Derived from an eyeball optical system model that separates lens refractive power and corneal refractive power,
    Relationship including focal distance f of subject eye with respect to total refractive power when lens refractive power and corneal refractive power are separated, and distance (image distance) s from fundus image side principal point of subject eye to fundus image A diopter, an axial length, and a corneal curvature input by the input means as variables,
  The calculation means obtains the object distance d by applying a predetermined value of the eyeball optical system model for optical characteristic information that is not input by the input means among diopter, ocular axial length, and corneal curvature.
An ophthalmologic measuring apparatus characterized by that. The ophthalmic measurement apparatus according to any one of claims 1 to 3,
  In the relational expression derived from the eyeball optical system model,
    An imaging formula of the focal length f of the subject's eye with respect to the total refractive power, the distance (image distance) s from the principal point of the fundus image of the subject's eye to the fundus image, and the object distance d;
    A relational expression between the image distance s and the diopter α,
    A relational expression between the object distance d and the axial length,
    Relational expression of focal length f when dividing corneal refractive power and crystalline lens refractive power,
    Relational expression of image side principal point when dividing lens refractive power and corneal refractive power,
    Relational expression of object side principal point when dividing lens refractive power and corneal refractive power,
  including,
An ophthalmologic measuring apparatus characterized by that.