Advanced Intraocular Lens Designs

Intraocular lenses (IOLs) have evolved since their introduction and spherical monofocal designs are no longer the only pseudophakic option. IOLs with a toric surface are able to correct astigmatism, but are dependent on the accuracy of placement. Haptic design is very important with toric IOLs as different designs demonstrate different post-operative rotational stability. Multifocal IOLs produce multiple focal points within the eye and so provide the capacity for simultaneous distance and near vision. Various mechanisms for creating these focal points exist, which determine how light is distributed. Accommodating IOLs use the optic shift principle in order to restore the accommodative response. Single and dual optic variations exist; however, the restoration of accommodation has been limited and variable with the current generation of these IOLs. Aspherical IOLs are designed to improve the optical quality of the image created by the IOL. Aspherical correcting IOLs are dependent on their centration and tilt. New phacoemulsification technology allows cataract removal through a sub-2mm incision, and microincisional IOLs can be implanted through these incisions, which results in minimal surgical impact on the cornea. Blue- and violet-blocking IOLs have been introduced, which might help prevent the development of age-related macular degeneration. Light-adjustable lenses are a relatively new technology and allow non-invasive post-operative adjustment of the IOL’s refractive power. This is a fast-moving area of research and development due to the high demands of clinical practice.