In the past decade, advances in cataract surgery and the reduction of the procedure’s astigmatic impact have paved a new avenue for refractive cataract surgery. With newly available multivariable IOL calculation formulas1 and improved understanding of the effective lens position2 and optics of the human cornea,3,4 we can now strive toward a predictable refractive outcome and offer patients minimal spectacle dependence after cataract surgery.
THE ART OF CUSTOMIZING IOL SELECTION
Despite these advances, not all patients are equal, not all eyes are equal, and, most important, not all lives are equal. Even when a patient is a great candidate for a specific type of IOL in terms of his or her optical system, the understanding of optical concepts and the development of new technologies will never replace the art of devising a specific a surgical plan for each patient’s lifestyle.
Presbyopia-correcting IOLs must be considered specifically from the perspective of each patient’s lifestyle. Multifocal IOLs may result in glare and halos5-7; therefore, a patient whose main symptom from cataracts are photic phenomena may be particularly sensitive to this side effect and should be thoroughly informed about this possibility. Multifocal IOLs also result in reduced contrast sensitivity compared with monofocal IOLs,8 which may be very relevant to some patients though negligible to others.
Similarly, monovision can be a great alternative for patients whose lifestyles do not require depth perception, and we have used this strategy in the past to minimize the need for spectacles. However, it could be a poor choice for those who require depth perception in their daily activities.
Different multifocal add powers can also be considered to fit diverse lifestyles. Today’s average person, whose activities occur more at long and intermediate distances than at near, will benefit from an extended depth of focus IOL or low-add multifocal IOL (+2.50 D to +2.75 D add), with the understanding that spectacles may be needed for near-distance tasks. In contrast, someone who drives only occasionally, does not frequently use a computer or tablet, and desires spectacle-free near vision may do better with a higher-add multifocal IOL (+3.00 D to +4.00 D add) and occasional spectacle wear for computer or tablet use. Further, the possibilities extend beyond the initial surgical plan, as any new refractive needs uncovered after the patient’s first-eye surgery can successfully be met by implanting a different multifocal add in the second eye.9,10
Cataract surgeons currently have many options to consider for IOL selection. This can overwhelm and confuse patients and unfortunately sometimes results in loss of trust and confidence in the surgeon. It is here where the surgeon’s expertise and knowledge becomes an essential tool for the patient to make an informed decision and where the art of medicine remains vital.
1. Gokce SE, Montes De Oca I, Cooke DL, Wang L, Koch DD, Al-Mohtaseb Z. Accuracy of 8 intraocular lens calculation formulas in relation to anterior chamber depth in patients with normal axial lengths. J Cataract Refract Surg. 2018;44(3):362-368.
2. Savini G, Hoffer KJ, Lombardo M, Serrao S, Schiano-Lomoriello D, Ducoli P. Influence of the effective lens position, as predicted by axial length and keratometry, on the near add power of multifocal intraocular lenses. J Cataract Refract Surg. 2016;42(1):44-49.
3. Rocha KM, Vabre L, Chateau N, Krueger RR. Enhanced visual acuity and image perception following correction of highly aberrated eyes using an adaptive optics visual simulator. J Refract Surg. 2010;26(1):52-56.
4. Rocha KM, Vabre L, Harms F, Chateau N, Krueger RR. Effects of Zernike wavefront aberrations on visual acuity measured using electromagnetic adaptive optics technology. J Refract Surg. 2007;23(9):953-959.
5. de Silva SR, Evans JR, Kirthi V, Ziaei M, Leyland M. Multifocal versus monofocal intraocular lenses after cataract extraction. Cochrane Database Syst Rev. 2016;12:CD003169.
6. Woodward MA, Randleman JB, Stulting RD. Dissatisfaction after multifocal intraocular lens implantation. J Cataract Refract Surg. 2009;35(6):992-997.
7. Maurino V, Allan BD, Rubin GS, et al. Quality of vision after bilateral multifocal intraocular lens implantation: a randomized trial–AT LISA 809M versus AcrySof ReSTOR SN6AD1. Ophthalmology. 2015;122(4):700-710.
8. Maxwell WA, Lane SS, Zhou F. Performance of presbyopia-correcting intraocular lenses in distance optical bench tests. J Cataract Refract Surg. 2009;35(1):166-171.
9. Hayashi K, Yoshida M, Hirata A, Yoshimura K. Short-term outcomes of combined implantation of diffractive multifocal intraocular lenses with different addition power. Acta Ophthalmol. 2015;93(4):e287-293.
10. Yang CM, Lim DH, Hwang S, Hyun J, Chung TY. Prospective study of bilateral mix-and-match implantation of diffractive multifocal intraocular lenses in Koreans. BMC Ophthalmol. 2018;18(1):73.