Artificial accommodating intraocular lens powered by an ion polymer-metal composite actuator

Abstract

The current method of controlling the focus of an accommodating intraocular lens is based on ciliary muscle contraction and cannot be used in older patients with presbyopia. We aimed to develop a dynamically accommodating intraocular lens powered by a membrane-shaped ion polymer metal composite actuator that is thin enough to be inserted in the eye. This study addresses two key problems identified in our previous accommodating intraocular lens prototype: the lack of repeatability due to the use of swine lenses instead of artificial lenses and the occurrence of a sixth order aberration. Thus, we present a new accommodating intraocular lens design and a method to transfer energy to actuators. To accommodate lens deformation and depth of focus, we used a membrane-shaped ion polymer metal composite actuator, thin enough to be inserted in the eye, and used an artificial silicone lens. To prevent the sixth order aberration, we included a ring between the ion polymer metal composite actuator and the lens. Different voltage patterns were applied to the IPMC actuator and changes in focus were observed. We were able to obtain repeatability and prevent the sixth order aberration. The dioptric power changed to ±0.23 D when ±1.5 V was used; however, at >1.5 V, a large accommodating range occurred, in addition to astigmatic vision. Thus, we have developed a novel prototype that is completely artificial, allowing reproducible and repeatable results. Visual accommodative demands were successfully met; however, although astigmatic vision was lessened, it was not completely eradicated.

New insights in presbyopia: impact of correction strategies

“…Early hinged and dual optic designs failed, largely due to fibrosis within the capsule as well as challenges in sizing to effectively couple with the natural changes in the capsule dimensions driven by the ciliary muscle97; newer designs have focused on shape changing optics 98–100. Soft polymers to replace the hardened crystalline lens are still being worked on101 and with lenses powered by a membrane-shaped ion polymer metal composite actuator,102 but this would need connection to an external battery and a method to detect ciliary muscle stimulation. However, human testing of these designs has, as yet, not been reported.…”