Accomodating Monofocal Intraocular Lenses
By fastening the IOL to the ciliary body, and making it from a material which can change focal length with shape or position, the need for glasses after cataract surgery can be reduced. This is called accommodation. Although they are called monofocal, standard IOL will exhibit slight accommodation. Several IOL have been designed to specifically exploit this concept.
The Crystalens IOL has been shown to give 90% of patients implanted had a near visual acuity of J3 or better, while only 15% of patients with a fixed focus IOL had that vision. This is a promising result, although near visual acuity is not as much of a challenge as distant visual acuity. For near visual acuity, the measurement is done at 14", while for distant visual acuity, the measurement is done at 20'. Intermediate and distance vision were improved, but not enough to do away with glasses.
The procedure costs about $4,500 per eye, compared to $1,600 for ordinary cataract surgery. This is the only FDA approved accomodating lens, but there are other technologies available.
Kellan Tetraflex KH-3500
Lenstec, an IOL maker in Florida, made another accomodating lens, comparable in price to Crystalens. It has been used in Europe and the Middle East. A study published by the British Journal of Opthamology was unenthusiastic about the product, (though less connected to the manufacturer than the above Crystalens study), particularly due to the stiffening of the lens's response at six months, while Crystalens remains flexible for at least 3 years.
SmartIOL from Medennium, Inc., in Irvine, CA, consists only of a full-sized, 9.5-mm diameter by 3.5-mm optic made of a thermodynamic, hydrophobic acrylic material
Other technologies in the works include the Sarfarazi Twin-Optic Elliptical Accommodating IOL, from Bausch and Lomb Rochester NY Quest Vision Technologies in Tiburon, CA, and reasearch from Advanced Medical Optics, Inc. Santa Ana, CA.