Abstract
Purpose:
To demonstrate the accommodative capabilities of a curvature changing intraocular lens.
Methods:
We previous demonstrated a concept for an accommodating IOL in which an elastic material is sandwiched between two rigid plates. One of the plates has a small aperture through which the soft material can be partially extruded when the plates are compressed. The extruded material takes on a roughly parabolic shape and consequently imparts optical power to the system. Here, we have fabricated a prototype lens consisting of a silicone gel with refractive index of 1.38 and a durometer value of 12 units on the “00” scale. The rigid portion of the IOL is fabricated from PMMA. To make the IOL increase in power in response to constriction of the ciliary muscle, the soft material needs to extrude into a higher index fluid. We evaluate a series of liquids, indexed matched to the PMMA, as well as lower index fluids in the index range of 1.44 to 1.48.
Results:
Compression of 100 microns of the silicone gel over a 3 mm aperture leads to a potential accommodative amplitude of 5.3 to 9.7 D for the fluids examined. There is concern of the fluid diffusing into the silicone gel and a membrane may be needed at this interface.
Conclusions:
he feasibility of an accommodating IOL based on curvature change of interface between a low index silicone gel and a high index fluid is demonstrated. The power change of the lens model works with the accommodation mechanism of the eye.
Keywords: 567 intraocular lens •
404 accommodation •
630 optical properties