IOL TECHNOLOGY

A new accommodating fluid-filled IOL has shown considerable promise in reducing the capsular bag opacification that frequently occurs after cataract surgery, according to Nick Mamalis MD, professor of ophthalmology, John A Moran Eye Centre, University of Utah, US.

“We found that when the capsular bag is maintained in an expanded and open configuration that there is little to no anterior or posterior capsule opacification formation. The results we achieved with this lens in the rabbit model are very impressive, as even the best IOLs will usually have significant PCO after six weeks,” he told a session of the XXXI Congress of the ESCRS in Amsterdam when reviewing results of a published study (Floyd AM, Werner L, Liu E, Stallings S, Ollerton A, Leishman L, Bodnar Z, Morris C, Mamalis N. Capsular bag opacification with a new accommodating intraocular lens. J Cataract Refract Surg 2013; 39:1415-1420).

Posterior capsular opacification (PCO) prevention methods have traditionally focused on design factors such as the IOL material and the utilisation of square-edge optics. Researchers have recently been exploring the potential of open and extended capsular bag models to prevent PCO and fibrosis. The FluidVision IOL (Powervision) is a hydrophobic acrylic accommodating lens with a hollow, fluid-filled optic and oversized haptics.

“The large balloon-like haptics are filled with index-matched silicone oil which flows back and forth between the haptics and the optic with accommodation, thereby changing the curvature and the power of the optic,” he said. Dr Mamalis performed bilateral phacoemulsification with IOL implantation in six rabbits, with each animal receiving both a FluidVision IOL and a control lens – a single-piece hydrophobic acrylic PCIOL (AcrySof, SA60AT, Alcon Inc.).

At six weeks, the PCO clinical score was 0.5 in the study group and 3.0 in the control group. Anterior capsule opacification was practically absent in the study group and mild in the control group. Miyake-Apple posterior view showed central PCO of zero in the study group and 3.0 in the control group, peripheral PCO of 0.66 in the study group and 3.5 in the control group, and Soemmering’s ring of 2.33 in the study group and 7.0 in the control group. Histopathology confirmed the relatively clean capsules in the study group and showed no signs of toxicity in either study or control eyes, said Dr Mamalis.

Nick Mamalis: nick.mamalis@hsc.utah.edu