In 2002, Chadwick was awarded National Institute of Health-National Eye Institute (NIH-NEI) Phase 1 grant EY014723 to develop field expansion eyeglasses capable of increasing the visual field, by 20 degrees, for people struck down by visual field loss, especially Hemianopia, the loss of vision in the same side in both eyes resulting from brain trauma, tumor and stroke. We know of no other ophthalmic lens laboratory to receive this honor. The resulting product, the "EP"-Horizontal or Expansion Prism lens was released to market April 1, 2005. The "EP" lens was also named for Dr. Eli Peli, MSC., OD., Senior Scientist at Schepens Eye Research Institute (SERI), an affiliate of Harvard Medical School. Dr. Peli originated the concept in 1999.
This grant strengthened our R&D base through our association with SERI in addition to the infusion of new technology into the laboratory, expanding our design and manufacturing capabilities.
The May 2008 issue of the Archives of Opthalmology reported the findings of the 2004-2005 clinical trial testing these mobility aids; the "EP"-Horizontal, or the Peli Lens™. Entitled "Community-Based Trial of a Peripheral Prism Visual Field Expansion Device for Hemianopia," the findings reported 74% of subjects continued to wear the aids at the end of the study, and 47% were still wearing them at the 12 month follow-up.
Chadwick was awarded a NIH-NEI Phase 2 grant in 2006 building on the successful completion of Phase 1. This second grant focuses primarily on increasing field expansion modestly over the Phase 1 design, but moving the field into midline view. A multi-site clinical trial is evaluating this design's usefulness for general mobility. The clinical trial started in November 2007. A secondary goal is to manufacture a complex device that could expand the visual field by more than 40 degrees by using prisms in excess of 80 diopters. This would effectively double the field expansion of the Phase 1 design.
Although the actual number of Hemianopes and Quadranopes is unknown, extrapolating data of stroke, head trauma and tumor cases indicate the number of new cases to be over one million per year in the U.S.