Purchase this article with an account.
Jim Schwiegerling, Nickolaos Savidis, Sean McCafferty; Curvature Changing Accommodating IOL. Invest. Ophthalmol. Vis. Sci. 2012;53(14):6331.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To demonstrate the accommodative capabilities of a curvature changing intraocular lens.
An elastic hydrogel material is sandwiched between two PMMA plates. One of the plates has a small aperture through which the hydrogel can be partially extruded when the plates are compressed. The extruded hydrogel takes on a roughly parabolic shape and consequently imparts optical power to the system. Previous versions of this technology have been demonstrated. However, these versions which are immersed in aqueous work counter to the natural accommodative mechanism of the eye. In other words, the plates are compressed resulting in increased optical power when accommodation is relaxed and a lower power is achieved when the eye is accommodated. We demonstrate a simple modification to this lens concept that allows the power change to occur in the proper direction. The hydrogel interface is immersed in a high index solution such as silicon oil. Under these conditions the extruded interface becomes a negative powered lens resulting in lower power when the accommodation is relaxed. Numerical simulations and artificial eyes are used to demonstrate this effect.
Compression of 100 microns of a hydrogel with index of refraction of 1.46 leads to a power change of 8.0 D when immersed in aqueous solution. However, again, the power change is in the wrong direction than what is desired for accommodation. When the aqueous is replaced with silcone oil with refractive index of 1.52, the same compression leads to a power change of 4.4 D. Furthermore, the direction of the power change works is correct for the eye’s natural accommodation mechanism.
The feasibility of an accommodating IOL based on curvature change of interface between a low index hydrogel and a high index fluid is demonstrated. The power change of the lens model works with the accommodation mechanism of the eye.
This PDF is available to Subscribers Only