2020–2021 BCSC Basic and Clinical Science Course™
13 Refractive Surgery
Chapter 8: Intraocular Refractive Surgery
Multifocal Intraocular Lenses
Multifocal intraocular lenses have the ability to provide appropriate patients with functional vision at near, intermediate, and far distances in each eye. This ability is due to lens multifocality that causes light rays to be split such that different focal points are created where objects will be clearest. However, all have potential trade-offs in vision quality and adverse effects, especially at night, and careful patient selection and counseling are necessary to achieve optimal outcomes. These types of lenses and their outcomes are discussed further in Chapter 9.
Patients who are likely to be successful candidates for an MFIOL implant after lens surgery tend to be adaptable, less visually demanding, and place a high value on reduced spectacle dependence at all distances. In addition, they should have good potential vision without significant pathology anywhere along the visual axis. Specific preoperative evaluation of macular function and anatomy may be warranted to exclude patients with macular degeneration, epiretinal membrane, or other conditions leading to suboptimal retinal function. Careful attention should be paid to evaluation of the corneal endothelium, as patients with Fuchs dystrophy may not be ideal candidates for MFIOLs. Significant anterior basement membrane dystrophy or tear film abnormality from dry eye syndrome or blepharitis may also adversely affect postoperative performance of these lenses. Patients with more than 0.75 D residual astigmatism after MFIOL implantation frequently have suboptimal vision quality. If this result is expected, strategies to reduce postoperative astigmatism should be evaluated and discussed before IOL implantation. Evidence has shown that patients generally have better visual outcomes if MFIOLs are implanted bilaterally.
Cionni RJ, Osher RH, Snyder ME, Nordlund ML. Visual outcome comparison of unilateral versus bilateral implantation of apodized diffractive multifocal intraocular lenses after cataract extraction: prospective 6-month study. J Cataract Refract Surg. 2009;35(6): 1033–1039.
Excerpted from BCSC 2020-2021 series: Section 13 - Refractive Surgery. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.