What are the different implantable devices available?

There are three different systems currently available for visual rehabilitation of AMD patients with implantable magnifying devices.

The IOL-VIP

The IOL-VIP system was developed by a group of eye surgeons and low ision specialists in Milan, Italy. This device consists of 2 IOLs (intraocular lenses) that are implanted inside the eye. One lens, which is highly concave (-55.00 diopters), is implanted behind the iris, while the other, which is highly convex (+50.00 diopters), is implanted in the anterior chamber (in front of the iris). This creates a telescopic effect offering 30% magnification. By displacing the two elements relative to one another, it is also possible to move the image onto an eccentric part of the retina. It can be implanted into both eyes. This is suitable for some patients, but because the magnification offered is 1.3 times (130%), only a very small number of patients with AMD are suitable for this, as this magnification is not enough to make a meaningful difference for most patients. The IOL-VIP is CE marked.

The IMT - Implantable Miniature Telescope (by Dr Isaac Lipshitz)

This implantable device for AMD consisted of a miniaturized Galilean telescope made of a glass cylinder that contains lenses and is embedded inside an IOL. The IMT creates a magnification of 2.2 times (220% Magnification) or 2.7 times (270% magnification) depending on the model used. The IMT is designed for implantation in one eye only as it creates magnification on the central visual field while totally obscuring the peripheral field on that eye so the patient uses his magnified central field of the implanted eye and the peripheral visual field of the other eye. I am informed by the manufacturer's that at present there is no plan to offer this technology outside the USA, but this position may change in time.

The LMI (Lipshitz Macular Implant)

The LMI is a telescopic IOL that is designed to magnify the image on the retina. The LMI is designed so that it is fully positioned inside the lens bag, this is the same position where lens implants are placed after cataract surgery.

The LMI contains miniature mirrors that are embedded inside it. These mirrors are configured, designed and accurately positioned in order to create a precise telescopic effect. The LMI creates 2.4 times (240%) magnification. When the LMI is implanted inside the eye the central light that is normally directed towards the macula, reaches the central mirror first and is then reflected to another peripheral mirror and finally projected towards the macular area.

The central mirror covers only a part of the pupil opening so that peripheral light rays can pass through the non-reflective surfaces of the LMI and reach the peripheral part of the retina normally. This way, the LMI incorporates a double optical system. In the centre of the retina there is a magnified image, which is projected onto the macular area. In the periphery the image is kept unchanged and unmagnified, as in a normal IOL (intraocular lens).

The central magnified vision, combined with at list part of the peripheral non- magnified vision, enables the patient to function almost normally as the orientation in space is done by the peripheral vision and is kept normal. When the patient looks at a certain object using the macula, the image is magnified and the patient can use the telescopic effect in order to read, work, etc. In order to have the magnified image focused sharply on the macular area, most patients will need new spectacles.  The LMI can be implanted in both eyes.

The LMI is not intended to cure the AMD disease but rather to help patients see and function better with the visual potential that was still left in their eyes. It is not a retinal implant. The LMI received the CE Mark in July 2009. The Company is also certified under the medical implants EN ISO 13485:2003.

Because of the limitations of the IOL-VIP and the IMT, for the majority of patients for whom an implantable magnifying system is advised, the LMI is likely to be the preferred device.

This page was last modified on Friday, June 11, 2010