Method of Intraoperative Refractometry of the Aphakic Eye

Abstract

Background. Correct determination of the optical power of the intraocular lens implanted in the eye for cataract treatment to achieve the planned postoperative refraction of the eye.

Objective. The aim of the research is reproduction postoperative refraction accuracy improvement during the cataract treatment by the artificial lens implantation without using preoperative biometrics of the eye.

Methods. The method of intraoperative refractometry of the aphakic eye based on the three-dimensional microphotometry of the illuminated macular microzone of the retina’s “air” image. For accurate definition of refractive parameters is proposed to use the root mean square radius values of the polar, axial and centrifugal moments that are dependent on the optical force of the virtual contact lens and defined in the distribution function of the illumination in the cross sections at the “air” image. Ametropia is determined by the minimum radii of the polar moment, and the astigmatism parameters are determined by the radii of the axial and centrifugal moments.

Results. The mathematical description of the method for intraoperative refractometry of aphakic eye for optical power determining of the intraocular lens and its hardware realization are developed. The functional diagram of the hardware and the formula for calculating the parameters of aphakic eye such as аmetropia and astigmatism based on data obtained with the help of this hardware is shown.

Conclusions. The proposed method of intraoperative refractometry is insensitive to optical obstacles caused by optical inhomogeneity of the eye and allows real-time calculations avoiding the use of traditional hardware preoperative biometrics of the eye and existing formulas for preoperative calculations of the optical power of the intraocular lens. The hardware implementation of the method allows determining the optical force of the virtual intraocular lens subjectively (with the patient participation), taking into account the planned value of postoperative refraction of the eye.