Mixing and matching IOLs the way to go

Mixing and matching diffractive and refractive multifocal lenses increases overall visual performance by enhancing range of vision, according to Angel López Castro of the Laservisión Clínica Oftalmológica in Madrid, Spain.

Implanting two different intraocular lenses (IOLs) in eyes of the same patient is not a new technique. However it is only now, with the advent of the new generation of multifocal IOLs, that this method is gaining popularity amongst cataract and refractive surgeons.

The idea first came to life when it was hypothesised that the combination of the advantages of two multifocal IOL technologies would allow surgeons to fully meet patient's needs, in terms of near, intermediate and distance vision under different light conditions.

While refractive multifocal lenses are proven to provide good intermediate vision, excellent distance vision and 100% light transmission, diffractive lenses offer excellent near vision, very good distance vision, whilst its actions are fully independent of pupil size. According to researchers, the processing of two different types of images is completely accepted by the patient and the brain.

At an AMO symposium, Castro presented his results from a study in which he implanted the diffractive Tecnis multifocal (AMO) and the refractive ReZoom multifocal lens (AMO) in the eyes of patients.

In the first group, 36 patients were bilaterally implanted with other multifocal lenses and received laser vision correction touch-up where necessary. Castro collected one-year follow-up data from this group. Meanwhile, 31 patients were implanted with the Tecnis MF and the ReZoom MF, without LASIK touch up, and followed for three months.

When assessing near visual acuity at follow-up, Castro found 85% of the mix and match patients could read J3 or better in mesopic conditions, in comparison to 70% of the bilateral other MIOL group. Furthermore, analysis of intermediate visual acuity with distance correction found 60% of mix and match patients could read J3 or better in photopic conditions, versus 20% in the bilateral diffractive group. Far visual acuity with distance correction was excellent in both groups.

Castro also performed a patient satisfaction survey and found that the majority of patients in both groups would choose the implanted lens again (other multifocal IOL = 82.4%, mix & match = 88.5%).

84.6% of mix and match patients admitted to never having to wear glasses, while the remaining 15.4% only had to wear glasses occasionally for either intermediate or near vision. In comparison, 81.8% of bilateral other MIOL patients did not wear glasses at one year postoperatively, while of the remaining 18.2% (half of whom required glasses constantly), glasses were required solely for intermediate vision correction.

With regards to the incidence of photic phenomena, 36% of bilateral other MIOL patients experienced severe glare, halos and difficulties in night vision, in comparison to the vast majority of mix and match patients (69% to 100%), who experienced either no or moderate photic phenomena.

Castro concluded by supporting the use of the mix and match technique in practice because it offers better near vision in dim light conditions, better intermediate vision, improved quality of vision overall and greater spectacle independence, when compared with implantation of just one type of multifocal IOL.

"The mix and match technique allows patients to fulfil all lifestyle expectations," he enthused.

Ophthalmology Times Europe reporting from the XXIV Congress of the ESCRS, London, 9-13 September, 2006.