Ophthalmic surgeons have been implanting multifocal lenses for several years, not only in cataract surgery, but also to offset the accommodation lost as a consequence of age. With the newest generation of lenses, more than 80% of refractive and cataract patients can now enjoy life without glasses.

The degree of patient satisfaction after multifocal lens implantation does, however, depend on whether exact emmetropy is obtained postoperatively; in up to 15% of cases, it is necessary to perform an additional refractive surgery procedure for the remaining ametropy in order to achieve this. Specifically, the bioptics approach is required and the procedure of choice is LASIK.

Figure 1

Earlier this year, I was able to overcome higher-grade preoperative astigmatism in a single procedure by implanting the new toric diffractive multifocal lens Acri.LISA Toric 466 TD (Acri.Tec, Germany) (Figure 1).

This lens model, which is made of hydrophilic acrylate with a hydrophobic surface, is a biconvex diffractive multifocal lens, with a diffractive aspheric back surface and an aspheric toric front surface.

The IOL can be implanted through a 1.5 mm incision and it does not induce any further astigmatism surgically, which is very advantageous for successful toric and refractive surgery. The new diffractive design also enables optimal optical imaging quality without diffused light.

Another requirement, which must be fulfilled particularly by a toric IOL model, is good postoperative rotational stability. Reiter et al.¹ showed no significant lens rotation (>4°) in 98% of cases six months postoperatively for the Acri.Smart 46, which is the basic model of the toric IOL. Meanwhile, Wehner² found neither rotation nor decentration with the same IOL model after 12 to 19 months.

The case study

A 44-year-old woman came to us desiring a LASIK procedure. She suffered myopia and astigmatism, and the early stages of presbyopia were also evident. We rejected a refractive procedure because of the keratoconus internus in her right eye. Distance vision preoperative in the right eye was -1.75-4.75/158° = 20/30 BCVA and in the left -4.54.0/4°= 20/40 BCVA.

Figure 2

We implanted the toric, diffractive multifocal lens in the right eye on 30 July 2007 and then in the left eye on 1 August 2007. Using a preoperative 0° marking on the split lamp with the Gerten marker and selection of a distinctive episcleral vessel in the corresponding axis, the precise axis was adjusted intraoperatively, using an individual monitor foil (Figure 2). For this, there are two markings on the IOL in the steepest meridian. It is helpful to check, and adjust if necessary, the axis position again after tonising the bulbus.

Figure 3

Four weeks postoperatively, there was a stable axis position in the right eye at 73° and in the left eye at 91° (Figure 3). The patient's distance vision in the right and left eye was 20/30 UCVA and binocularly it was 20/25 UCVA. Near vision was 20/25 UCVA right and left at a distance of 40 cm and binocularly it was 20/20 UCVA.