Multifocal IOLs with apodized diffractive central zone and refractive periphery: optical performance and clinical outcomes

The apodized diffractive multifocal intraocular lens is one of the intraocular lens types currently available for the correction of presbyopia. The design of apodized diffractive multifocal intraocular lenses improves on the visual outcomes obtained with the full optic diffractive and refractive intraocular lenses. In addition to the visual improvements, apodized diffractive multifocal intraocular lenses, using a combination of diffractive and refractive technologies and gradually decreasing diffractive steps from the center to the periphery of the intraocular lens, reduce or eliminate the visual phenomena produced mainly in night conditions when the pupil size increases. J Emmetropia 2014; 5: 155-166 Submitted: 01/21/2014 Revised: 03/17/2014 Accepted: 04/24/2014 1Vallmedic Vision Andorra. 2School of Health Sciences. La Salle University, Bogotá, Colombia. Financial disclosure: The author has no proprietary or commercial interest in the medical supplies discussed in this manuscript. Acknowledgements: To Manuel Alejandro Amaya Alcaraz and Ane Murueta-Goyena Larrañaga for their collaboration in the review of this manuscript. Corresponding Author: Javier Tomás-Juan Department of Visual Science. Vallmedic Vision Andorra. Avinguda Nacions Unides 17. AD700 Escaldes-Ergordany, Andorra E-mail: [email protected] Nowadays, diffractive multifocal intraocular lenses (IOLs) are considered a good alternative for the correction of presbyopia1. The working principle of the full optic diffractive multifocal IOLs is based on the creation of two focal points, by using diffraction orders (order 0 and order 1)1. The power corresponding to the 0-order diffraction is used to image distant objects, whereas the power corresponding to the 1-order is used for near vision1. In diffractive multifocal IOLs, the image is divided into two focal points, one for distant vision and the other one for near vision, so one of the images will always be sharp whereas the other one will be barely perceived or blurred. The blurred image is usually said to be located in the blur circle2. Nevertheless, full optic diffractive multifocal IOLs have the disadvantage that the image formed by one of the foci in the retina will have the defocused image from the other focus superimposed along the optical axis. This can cause side effects, such as glares and halos, mainly in mesopic and scotopic conditions when the pupil diameter is increased1,3-14. Furthermore, due to the design of the diffractive multifocal IOLs, patients who have been implanted may have lower contrast sensitivity (CS) values3,4,6,11-16, mainly due to forward dispersion and the higher-order aberrations (HOA)2,17. It is very important to consider the visual effects of the multifocal diffractive IOLs, such as night vision disturbances18, and dissuade people with nighttime visual needs, for example, professional drivers, from undergoing this surgery13. To reduce the visual effects mainly produced in night vision with full optic diffractive multifocal IOLs, IOLs combining refractive technology with diffractive technology have been introduced2,13,19.