Influence of angle Kappa on the optimal intraocular orientation of asymmetric multifocal intraocular lenses

  1. Sergio Bonaque 1
  2. Matt T. Jaskulski 2
  3. David Carmona Ballester 3
  4. Alicia Cristina Pareja Ríos 4
  5. J.M. Trujillo Sevilla 1
  1. 1 Wooptix S.L. San Cristobal de La Laguna, Santa Cruz de Tenerife, Spain
  2. 2 Universidad de Murcia

    Universidad de Murcia

    Murcia, España


  3. 3 Universidad de La Laguna

    Universidad de La Laguna

    San Cristobal de La Laguna, España


  4. 4 Hospital Universitario de Canarias

    Hospital Universitario de Canarias

    San Cristóbal de La Laguna, España


Journal of Optometry: peer-reviewed Journal of the Spanish General Council of Optometry

ISSN: 1888-4296

Year of publication: 2021

Volume: 14

Issue: 1

Pages: 78-85

Type: Article

DOI: 10.1016/J.OPTOM.2020.07.004 DIALNET GOOGLE SCHOLAR lock_openOpen access editor

More publications in: Journal of Optometry: peer-reviewed Journal of the Spanish General Council of Optometry


Purpose to evaluate the effects of kappa angle and intraocular orientation on the theoretical performance of asymmetric multifocal intraocular lenses (MIOL). Methods For a total of 21 corneal aberrations, a computational analysis simulated the implantation of a computationally designed MIOL. An image quality parameter (IQ) (visually modulated transfer function metric) was calculated for a 5.0-mm pupil and for three conditions: distance, intermediate, and near vision. The procedure was repeated for each eye after a rotation of the MIOL with respect to the cornea from 0º to 360º in 5º steps. Kappa angles from 0 to 900 microns, in 150 microns steps, combined with two two variants of MIOL centration were tested: in the corneal apex or in the center of the entrance pupil. A p-value ≤ 0.05 was considered significant. Results There were statistically significant differences of the IQ depending of the intraocular orientation of the MIOL. If kappa angle was increased, there was a statistically significant decrease of the IQ. The IQ maintained stable when the optimal intraocular orientation was re-calculated for each kappa angle. In general, the inter-variability of the results between subjects was very high. There were no strong evidences supporting that there exists a preferable centration point. Conclusions Our results suggest that kappa angle theoretically affects significantly the performance of asymmetric MIOL implantation. However, its negative effect can be compensated if a customized intraocular orientation is calculated taking into account the presence of the kappa angle.