Macular degeneration is a disease involving the macular portion of the retina. The macula is responsible for the clear central vision that we use in our daily activities. Patients with macular degeneration lose the ability to read, watch TV, or drive a car as the macular degeneration progresses. Most people still maintain their side vision and are able to ambulate. Telescopic glasses and other magnification devices have limited success due to the difficulty of using those systems. Patients with end-stage macular degeneration are looking for a way to improve their life with useful vision.
Telescopic Intraocular Lenses for Macular Degeneration
Recently the Implantable Miniature Telescopic (IMT) lens received FDA approval for use in cataract surgery in patients with end-stage non treatable macular degeneration. The lens is made out of polymethyl methacrylate haptics and requires a large incision in the eye in order to insert it into its proper position. The lens is stiff and the surgeon cannot fold the lens to place it through a smaller incision as with regular intraocular lenses used in normal cataract surgery.
Redesigned Telescopic Intraocular LensThe new lens is redesigned and made from silicone haptics (a loop that holds the lens in proper position in the capsular bag of the human lens after the cloudy lens material is removed). These lenses are foldable and can be inserted through a smaller incision. The LMI-Mirror Telescopic lens is designed with miniature mirrors in a Cassagrain telescopic configuration. The lens has a dual action optical system in that light going through the center of the lens is magnified by the telescopic portion of the lens and light passing through the peripheral portion of the lens is focused in a normal intraocular lens manner.
The lens is 13mm in diameter. The optical portion of the lens is 6.5mm in diameter. The lens provides a magnification of 2.5 times on the surface of the retina.
The original Implantable Miniature Telescopic lens has some issues with the difficulty of the insertion, the size of the incision, loss of endothelial cells (inside layer of cells on the underside of the cornea), and decreased peripheral vision.
The design of the new LMI-Mirror Telescopic lens is similar to regular intraocular lenses used for cataract surgery. It provides 2.5 times magnification centrally onto the retina while maintaining peripheral vision. Because of the normal side it may be implanted in both eyes instead unilaterally with the original design.
The design of the lens allows for better visualization of the retina. Fluorescein angiograms and photos can be done through the lens. Endothelial cell loss from the cornea is similar to regular cataract surgery.
Sixty percent of patients had an improvement of three lines or more in their vision.
This lens is not yet available in the United States at this time.