THE ADVANCED PRACTICE …

Material and Design of the Akreos MICS Lens Foster Excellent Long-Term Results

A special series sponsored by Bausch + Lomb

When surgeons first implant the Akreos AO Micro Incision Lens (Akreos MICS), they tend to be quickly impressed with several attributes, in particular its transparency, nearly instant centration and corneal clarity the day after surgery. The Akreos MICS lens (model MI60L, Bausch + Lomb) has been available to U.S. surgeons for more than a year and they're finding the same material and design features that provide immediate benefits also contribute to excellent long-term performance. Their experience is mirroring that of their European colleagues, who have been using the lens since 2006.

About the Akreos MICS Lens

The Akreos MICS lens is the only IOL approved for use in the United States that can be implanted through an un-enlarged sub-2-mm incision. It's the newest addition to Bausch + Lomb's exclusive MICS Platform, which now includes all of the tools necessary for performing true microincision cataract surgery (MICS): the Stellaris phaco machine, Storz instruments, Amvisc Plus OVD, Viscoject Lens Injection System and the Akreos MICS lens.

The Akreos MICS lens is the latest addition to the Akreos family of IOLs, which have been implanted in more than 3 million eyes worldwide. The single-piece lens is made from a highly biocompatible hydrophilic acrylic material and features a spherical-aberration-free optic, innovative four-haptic design for maximizing centration and stability, and an enhanced 360° square edge and 10° angulation designed to minimize posterior capsule opacification (PCO).

More than 500,000 Akreos MICS lenses have been implanted globally to date and within 6 months of its U.S. debut, it has become the lens of choice for micro incision surgeons. Here, two U.S. surgeons discuss their long-term results with the lens and why it's their monofocal IOL of choice.

Material Makes a Difference

Anna F. Fakadej, MD, FACS, FAAO, was the first surgeon in the mid-Atlantic region to implant the Akreos MICS lens at Carolina Eye Associates, which has eight locations in North and South Carolina. "This is a remarkable lens," she says. "The material is the first important piece of the puzzle. It's a combination of polymethylmethacrylate (PMMA) and hydroxyethylmethacrylate (HEMA). The PMMA, which has been used intraocularly for decades, provides the strength and structure. The HEMA allows for compactibility and flexibility so the lens can be folded and inserted into a tight space. Yet when it expands, it's elasticity allows it to return to its original shape and structure. I think of the PMMA as the weightlifting aspect of the lens and the HEMA as the yoga aspect. The lens is easy to insert and it opens smoothly in the capsular bag." (Figures 1-3)

Figures 1-3. In this case, the Akreos MICS lens was inadvertently loaded upside down, incorrectly angling the haptics posteriorly. However, highlighting the IOL's insertion characteristics, the surgeon was able to turn over the inserter 180 degrees and complete a smooth and timely implantation. There was enough time to manipulate the lens, and it was properly placed within a few seconds.

Louis D. "Skip" Nichamin, MD, medical director of Laurel Eye Clinic and Laurel Laser & Surgery Center with locations throughout western and central Pennsylvania, also commented on the Akreos MICS lens material. "The clarity of this material is unsurpassed in my experience," he says.

"The lack of glistenings and complaints of dysphotopsia make it optically superior to other choices on the market. It's very biocompatible as well. In my experience, a more hydrophilic material tends to be more compatible with uveal structures."

Durable Stability and Quality of Vision

Dr. Fakadej credits the neutral spherical aberration of the Akreos MICS lens optic for the high rate of satisfaction among her patients. "They have sharper vision and good contrast sensitivity in variable light conditions and many retain more depth of focus compared with other lenses," she says.

The IOL's excellent centration and stability in the eye also play a role, she says. The lens has four haptics instead of two, which helps to ensure immediate centration upon injection. Furthermore, the loops are uniquely designed to bend and absorb forces in three dimensions during postoperative contraction of the capsular bag. It has been shown to have a mean decentration of just 0.11 mm at one year after implantation.¹

"The four haptics nicely fill and stretch the capsular bag," Dr. Fakadej says. "I rarely see wrinkling of the bag with this design, and there's very little lens movement over time. I've even used the lens in cases with some weakening of the zonules, where it actually seems to preserve capsular stability. For the most part, it is my lens of choice in IFIS and other small-pupil cases as well." (Figures 4 and 5)

Figures 4-5. The stability of the Akreos MICS lens in the eye makes it suitable for cases in which postoperative decentration could be a problem, as shown here with the use of a Malyugin ring.

Both Drs. Fakadej and Nichamin report low PCO rates with the Akreos MICS lens. "This lens has a very low rate of PCO if the posterior capsule is polished," Dr. Fakadej says. "When a YAG procedure is necessary, it's quite easy. The capsule doesn't seem to fibrose to the lens as it does with other IOLs, so pitting of the lens is much less. In cases where I've seen pitting, it has resolved over a few days."

Dr. Nichamin says he has seen PCO slightly earlier in eyes with the Akreos MICS lens compared with other lenses, "but certainly at an acceptable rate, and in many cases this faint haze isn't visually significant. We usually detect it long before the patient notices any change in their vision. Long-term, I think we'll find the overall incidence to be comparable to other lenses."

New Era in Cataract Surgery Well Under Way

Dr. Nichamin continues, "In my opinion, early signs of capsular fibrosis, as long as it remains at a reasonable rate, is a more than acceptable trade-off in order to have a lens with optically superior performance that I can implant through such a ‘micro’ incision. Being able to implant the Akreos MICS lens through an unenlarged 1.8-mm wound is a tremendous benefit in that I'm not inducing any measurable astigmatism.^2,3 Just as importantly, it renders a new level of intraoperative control so that I can better dictate what happens to the intraocular mileu. In a complicated case, such as IFIS, a smaller incision, even if it's incrementally smaller, is immensely important to the final outcome. These smaller incisions are easier to perform, particularly in regard to the creation of square wound architecture, which we know is crucial for wound integrity, and this will likely lead to less incisional leakage and potentially less risk for endophthalmitis.

"We're beginning to see long-term outcomes with the Akreos MICS lens. Given the time span for which I have been using the lens as well as the absolute number I have implanted, I certainly feel comfortable with its long-term performance."

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Joel Pynson, MD, director of design engineering at Bausch + Lomb, Toulouse, France, contributed information for this article.

REFERENCES

1. Amzallag T. Akreos Micro-Incision IOL: final results of a pilot clinical study at one year follow up. Free Paper. ESCRS 2006.
2. Dick HB. Bi-axial microincision versus co-axial small incision using the Stellaris Vision Enhancement system. Paper presented at the Annual Congress of the ESCRS, Barcelona, 2009.
3. Rajan M. Akreos MICS lenses-our experience. In: New dimensions in hydrophilic acrylic IOLs. Presented at the annual meeting of the ASCRS in San Francisco, CA, 2009.

This reprint of a published article is provided for educational purposes. The results described in this article are those of the author or investigator identified in the article and may differ from the product's approved labeling. Please refer to the instructions for use or other labeling provided with the product for complete details and instructions regarding the product.