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Please Note: The technology listed below is not available to the public at this time. This technology is in the early stage of research and requires further development before it is ready for the marketplace. The VA is currently in the process of identifying potential companies who may be interested in licensing and/or further developing the technology through Cooperative Research and Development Agreements (CRADA). Through cooperative research initiatives such as these, it is our hope and goal that commercial products will be fully developed and made available to benefit veterans and others.
VA TECHNOLOGY OPPORTUNITY BRIEF
Synthesis of an Artificial Human Lens that can Potentially Eliminate Bifocals
(02-125)
OPPORTUNITY:
The Department of Veterans Affairs (VA) is seeking a commercial partner to further develop a technology that consists of a viscous polymer solution free of toxic monomers and other undesirable additives that can gel spontaneously within the lens capsular bag. The gel can be formulated to exhibit optical and mechanical properties similar to a youthful lens and thus has the potential to eliminate bifocals, glasses, or contact lenses.
BACKGROUND:
A cataract is a cloudy or opaque area in the normally transparent crystalline lens of the eye. Surgery is required to remove the cataract when a person is unable to see well enough to perform everyday activities. Over two million cataract surgeries are performed each year. In modern cataract extraction surgery, the cataract is removed from the lens through an opening in the lens capsule and is replaced with a permanent, clear plastic intraocular lens (IOL) implant. IOLs can be divided into two main groups: non-foldable and foldable. Non-foldable IOLs were made from a hard plastic material and could only be introduced into the eye with an incision as large as the diameter of the lens. In order to reduce eye trauma and to keep the surgical incision small, foldable lenses made of acrylic or silicone were developed. The foldable IOLs require only a very small incision and gently unfold once inside the eye. Although these standard IOLs are available in a variety of focal lengths, those lengths are fixed for any given lens. Unlike the natural lens of the eye, a standard IOL is unable to change focus. Therefore, a patient with standard IOLs loses accommodative capability after surgery and may still require the use of reading glasses. Bifocal and multifocal IOLs can eliminate the need for glasses, but they also produce contrast reduction and halos around lights. Therefore, a need exists for a material that could mimic the natural lens of the eye and eliminate the need for reading glasses after cataract surgery. A material has been developed that consists of a viscous polymer solution which can change its shape within the eye and thereby its focal length. In addition, this material could also be used to treat other refractive errors like presbyopia, the physiologic loss of accommodation in the eyes due to advancing age, which cannot be treated by current laser refractive surgery.
TECHNOLOGY OVERVIEW:
This polymer gel consists of individual chains of polymers linked by disulfide (sulfur to sulfur) chemical bonds. The gel is thoroughly washed to remove any traces of impurities and then liquefied by breaking these disulfide bonds to form a honey-like viscous solution. This polymer solution can spontaneously solidify back into a soft gel within a body cavity under normal physiological conditions, such as ambient temperature, pH, and oxygen. When injected into the eye, it has the potential to be used as an intraocular lens implant during cataract surgery. Since the solid polymer is soft, pliable and transparent, it takes the shape of the lens capsule and is capable of changing focal length within the eye. This technology could allow patients to see clearly at a range of distances, thus eliminating the need for reading glasses and lessening surgical trauma. Based upon its physical properties, the polymer may also be useful in other situations where a biocompatible gel might be required, such as vitreous substitutes and depot drug delivery, a method in which a drug is mixed with the injected gel and then slowly diffuses out of the gel and into the body.
TECHNICAL MERIT:
The polymer possesses several attributes that would make it a superior material for IOLs:
- . It is injectable.
- . It eliminates the need for post-operative reading glasses in cataract patients.
- . It reduces the level of surgical trauma experienced by cataract surgery patients.
- . It eliminates the contrast sensitivity and halos typically experienced by patients with surgically inserted bifocal and multifocal intraocular lenses.
- . It possesses a chemical similarity to natural proteins.
- . It is likely to resist degradation better than ester-based hydrogels.
- . It can be changed from a gel back into a liquid, if necessary, for easy removal and reinsertion.
IP STATUS:
Provisional patent application number 60/425,764 was filed on November 13, 2002.
A US patent application was filed on November 13, 2003 (10/706,081).
International patent application filed on September 03, 2004 (PCT/US04/028637).
CIP patent application filed to 10/706,081 (awaiting filing date & S/N).
A US non-provisional application was filed April 4, 2006 (10/574,667).
FOR MORE INFORMATION CONTACT:
Saleem Sheredos
Program Manager
Technology Transfer Program
Veterans Affairs
Office of Research & Development (12TT)
5th Floor
103 South Gay Street
Baltimore, MD 21202
202-380-5080
Fax 410.962.2141
e-mail: saleem.sheredos@va.gov