IOL designs maintaining an open or expanded capsular bag

Sep 05, 2010

Dr Liliana Werner talks about her research at the John A. Moran Eye Centre at the University of Utah looking at the design features of IOLs that help prevent post-op capsular bag opacification.

The Concept 360 from Cornéal Laboratoires, a new disc-shaped IOL from Anew Optics, a dual-optic accommodating IOL (Synchrony), and FluidVision, a silicone oil-filled IOL are four different intraocular lens designs that maintain the capsular bag open or expanded, helping to prevent postoperative capsular bag opacification. All four have been investigated by Dr Liliana Werner and colleagues at the John A. Moran Eye Centre at the University of Utah in their studies, which were presented at The Clinical Research Symposium in Paris on the opening day of the XXVIII ESCRS Congress.

Dr Werner and colleagues employed both rabbit and human eyes obtained postmortem, in their experimental studies. Dr Werner told OTEurope: “The rabbit eye studies found that posterior capsule opacification (PCO) was significantly less in those designs that maintain an expanded capsular bag compared with standard 3-piece or single-piece lenses.”

IOL designs

The large haptic elements of the FluidVision accommodating IOL ensure the anterior and posterior capsules are kept apart. The optic and haptic interior is filled with silicone oil that is index-matched to the hydrophobic acrylic material. Once the haptic is subjected to accommodative forces the oil is pushed into the optic via fluid channels connecting the haptics to the optic. As this happens an internal actuator, driven by fluid gets pushed forward and the front optic surface is deformed and the power of the lens increases.

The Synchrony dual-optic accommodating IOL has been developed with two separate optics connected by a spring system. The posterior element of the lens has a greater surface area than the anterior aspect, which provides stabilization and centration within the capsular bag. The aqueous channels of the anterior optic, parallel to the haptic, lift the capsulorhexis edge up preventing the anterior capsule from completely touching the anterior surface of the lens. This assists with preventing anterior capsule opacification (ACO).

The Concept 360, which was designed by Dr Philippe Sourdille, is a single-piece, hydrophilic acrylic IOL that keeps the anterior capsule away from the IOL optic; the six haptic components with a 10-degree posterior optic-haptic angulation also create the same effect of a capsular tension ring preventing PCO.

Anew Optics, which recently secured funding of $952,000 of a $2 million planned equity offering, is developing a single-piece, hydrophilic acrylic monofocal lens. The optic is suspended between two complete haptic rings that are connected by a pillar of the haptic material. The anterior ring rests against the anterior capsule at some distance from the capsular equator, and the posterior ring rests against the posterior capsule also at some distance from the capsular equator.

Dr Werner said the studies' findings did support other investigations into preventing capsular bag opacification such as those by Hara et al., in the early 1990s1,2 and Menapace and Nishi et al., in 2008.3

References1. T. Hara et al. Ophthalmic Surg 1990; 21:128-133. 2. T. Hara et al. Ophthalmic Surg 1992; 23:632-635. 3. R. Menapace, O. Nishi, et al. J Cataract Refract Surg 2008; 34:1318-2138.

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