gms | German Medical Science

Purpose: The IC-8 (AcuFocus) is a recently introduced IOL that uses a small-aperture principle to extend the depth of focus. This pinhole IOL aims to provide an excellent distance vision that one expects of monofocal lenses. The purpose of this study was to evaluate the image quality of the IC-8 and compare it with a diffractive EDoF and a monofocal IOL.

Methods: An optical-bench setup was used to study image-quality metrics of the pinhole IOL, a diffractive EDoF (Symfony, J&J), and a standard monofocal (SA60AT, Alcon) lens. A -0.75D refraction target was simulated for the IC-8 and plano for the other IOLs. The IOLs’ modulation transfer function (MTF) was measured, and the MTF area was calculated to compare the lens performance at a range of defocus values. IOLs’ tolerance to misalignment was assessed up to 0.75 mm of decentration.

Results: The MTF analysis showed one extended focus area centered at -0.75D, but the Symfony demonstrated two peaks at zero and 1.75D, with the minimum occurring at (approx.) 1D. Despite the myopic target, the pinhole lens had a comparable MTF as the monofocal lens at the far focus, and a higher MTF area than the diffractive IOL by 24%. At the intermediate range (1.75D), the Symfony and the pinhole lens performed similarly and were superior to the SA60AT in terms of defocus tolerance. The optical quality of the monofocal lens virtually did not change with decentration, but it affected the performance of the two EDoF IOLs.

Conclusion: We demonstrated that the small-aperture lens provides an EDoF effect that is comparable to that of the Symfony and has a similar image quality as the monofocal lens at distance. A myopic target of -0.75D increases the range of intermediate and near focus in patients with the pinhole IOL.