US Patent 5,322,859
United States Patent and Trademark Office
University of Iowa Research Foundation (Oakdale, IA, US)
Use of sigma agonists as ophthlamic drugs for lowering intraocular pressure.
Schoenwald, Ronald D. and Barfknecht, Charles F. Antiglaucoma drug composition and method. US Patent 5,322,859 filed February 08, 1993 and issued June 21, 1994. https://ir.uiowa.edu/patents/120