MULTIFOCAL IOLS

The AT LISA 809M multifocal lens provides good near and distance vision with few untoward effects in the longer term, according to a series of reports at the Annual Congress of the ESCRS in Amsterdam. Maria Sysoeva MD, presenting for Dimitrii Dementiev MD, Centro di Microchirurgia Oculare, Milan, Italy, discussed the long-term results of the AT LISA 809M (CZ Meditec) multifocal lens.

Dr Sysoeva’s study included 422 eyes of 211 patients, of whom 62 per cent were female. A single surgeon operated all patients under topical anaesthesia, using a 2.4mm incision and standard phacoemulsification. Patients were followed up for 36 months, with regular follow-up visits at one, three, six, 12, 24 and 36 months. There were no surgical complications. “Mean uncorrected distance visual acuity improved from 20/50 to 20/25, and average uncorrected near VA was 20/30,” said Dr Sysoeva.

Spectacle independence was observed in all but five cases for intermediate vision and in all but one case for near vision. However, haloes were reported in three cases, or 1.4 per cent of the eyes. Nevertheless, all patients showed high levels of satisfaction regarding both near and far vision. “For many patients, cataract surgery has become a refractive surgery procedure. Whereas the main problem after cataract surgery was aphakia in the 1960s and 1970s, astigmatism in the 1980s and spherical aberration in the 1990s, the main problem in this era is the need for spectacle correction, particularly for near,” she commented.

The AT LISA 809M lens is made of hydrophilic acrylate with hydrophobic surface properties, and has a +3.75 D near addition throughout the power range from 0.00 to +32.00 D. It was the first preloaded multifocal micro-incision IOL made available. Dr Sysoeva added that the standard AT LISA multifocal IOL exhibits good predictability in terms of refractive outcomes.

The AT LISA is also available with cylinder correction. Matteo Piovella MD, scientific director, Centro Microchirugia Ambulatoriale, Monza, Italy, presented his team’s two-year outcomes for distance and near vision after implantation of the AT LISA 909M toric IOL. Dr Piovella begun with a review of what are generally considered to be the disadvantages of the most popular multifocal IOLs. “The well-known problem of contrast sensitivity reduction is not the only potential pitfall,” said Dr Piovella. “Others include poor intermediate distance vision, light loss due to differing diffraction efficiency, along with haloes, glare and ghost images, which are particularly difficult to manage in suspicious patients.”

Dr Piovella recommended toric multifocal IOLs for corneal astigmatism above 0.75 dioptres. He then introduced the lens, which he described as “an advanced-generation, multifocal IOL preferably indicated for bilateral implantation.” His study, which treated 33 eyes of 21 patients with a mean age of approximately 62 years, had a two-year follow-up. BCDVA, postoperative mean refractive astigmatism and mean sphere equivalent, as well as binocular near visual acuity were recorded. IOL calculations took into account the surgically induced astigmatism. IOL axis alignment during surgery was performed using limbal and iris patterns. Preoperative mean corneal astigmatism was 1.78 D.

The preoperative mean total refractive astigmatism was 1.46 D. This was reduced to 0.47 at two years postoperatively, said Dr Piovella. Distance BCVA was also good, at 0.9 at two years postoperatively, while monocular near uncorrected visual acuity was 25/34, or J2. Photopic contrast sensitivity, measured using the Optec 6500, was within the normal range for lower spatial frequencies.

“What is crucial to the long-term postoperative success of a toric lens is the rotational stability of the IOL, as well as its centration. Because of their 4-haptic design, the Zeiss IOLs have been shown to have excellent rotational stability and stable centration, as shown in a study by Dr Michael Georgopoulos, MD of Austria.”

To illustrate his point, Dr Piovella showed sequential images of a lens that rotated two degrees over the course of one year postoperatively. A relatively high number of eyes, seven of 33 (21.2 per cent), underwent YAG posterior capsulotomy within one year postoperatively. “Preoperative counselling is crucial, particularly in terms of managing expectations. It doesn’t take very long, and it is quite beneficial in the long term to avoid patient dissatisfaction due to unrealistic expectations,” emphasised Dr Piovella. “Clinical outcomes indicate that the AT LISA 909M toric IOL is an effective multifocal design for the correction of corneal astigmatism, providing effective uncorrected distance and near vision.”