Optical-Quality Assessment Of Multizonal-Refractive And Diffractive-Trifocal Intraocular Lenses For Presbyopia Correction

The literature indicates that multizonal-refractive intraocular lenses (IOLs) can increase the postoperative visual range of pseudophakic patients; however, it has yet to be evaluated whether this approach could be an alternative to diffractive-trifocal technology. This study compared the optical performance of a multizonal-refractive presbyopia-correcting model and a conventional trifocal across the functional defocus range.

David J. Apple Center for Vision Research, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany

The optical quality and simulated visual acuity (VA) of 570 Precizon Presbyopic NVA (OPHTEC BV) and AcrySof IQ PanOptix (Alcon) were compared. The Precizon features a refractive design consisting of alternating optical zones that converge the incident light into two principal foci and a transitional zone for intermediate vision. By contrast, the PanOptix applies a diffractive (non-apodized) profile to achieve trifocality. Simulated VA was derived from the modulation transfer function. Chromatic aberration effects were also studied.

 The diffractive and the multizonal-refractive IOLs yielded comparable VA at far focus (0.00 logMAR). All curves showed a reduction in visual acuity with the increase in negative defocus. At -1.0 D, refractive IOL's simulated VA dropped by 0.05 logMAR, but for the diffractive lens, it was one line (0.11 logMAR). The multizonal lens's VA prediction at the secondary peak was 0.03 logMAR - minimally better than 0.06 logMAR of the diffractive lens at -2.5 D.

The multizonal-refractive lens does not fall short of the established trifocal IOL and can be used to extend the visual range of pseudophakic patients. Although the multizonal-refractive lens has lower material dispersion, the diffractive model corrects chromatism beyond the far focus.