ANALYSIS OF WAVEFRONT DATA OBTAINED WITH A PYRAMIDAL SENSOR IN PSEUDOPHAKIC EYES IMPLANTED WITH DIFFRACTIVE INTRAOCULAR LENSES

Recent developments in high resolution wavefront sensing might allow to bypass the limitations imposed by Hartmann-Shack devices to measure the wavefront of patients implanted with a diffractive intra ocular lens (IOL). The purpose of this work was to investigate the clinical validity of using wavefront measurements obtained with the recently available high-resolution aberrometer Osiris-T (CSO, Italy), to assess the optical quality of eyes implanted with a diffractive IOL design.

Clinsborges, Porto, Portugal and Physics Center of Minho and Porto Universities (CF-UM-UP) - University of Minho, Braga, Portugal.

Individual biometric data was collected and used to create models of twelve pseudophakic eyes implanted with a trifocal and an EDOF diffractive IOL. Their synthetic wavefronts were calculated by raytracing with near-infrared light with the same wavelength used by the aberrometer (0.85μm) and scaled to 0.55μm to compensate for the wavelength dependence of the diffractive IOL. Differences between through-focus image quality pre and post scaling were compared with the reference data, obtained with a 0.55μm wavelength. Through-focus simulated visual acuity (sVA) curves calculated from the wavefront data measured with the Osiris-T were compared to clinical VA curves and to sVA theoretical expected values calculated from raytracing in the customized eye models.

Image quality calculated from wavefront data obtained by raytracing at 0.85μm wavelength without scaling the phase to 0.55μm resulted in significantly different through-focus curves compared to the reference values. After scaling the phase, the defocus curves calculated from the wavefronts measured with the Osiris-T still do not match the shape and the depth-of-field of the clinical defocus curves or the theoretical sVA expected values.

Correcting for the longitudinal chromatic aberration of the eye when measuring the wavefront of eyes implanted with diffractive IOLs under near-infrared light only accounts for the best focus shift but not for the IOL wavelength dependence. The lateral resolution of the Osiris-T does not seem to be enough to sample the slopes of wavefronts from pseudophakic eyes implanted with diffractive IOLs to a clinical acceptable level.