NAPA -- Santen Pharmaceutical, a developer of eye-care products, announced it will relocate its U.S. operations from Napa to Emeryville this summer.

The U.S. subsidiary of Japan-based Santen Pharmaceutical Co.  said about 65 employees will be relocated to 50,000 square feet of new office space at 2100 Powell St. in the East Bay city. The move is planned for July.

Closer access to Bay Area airports, a more central location in the region, better communication with partners in Japan, greater access to talent and shortened commutes and more transportation options for employees prompted the move, according to Santen.

"In the light of further driving its R&D functions by expanding its clinical development organization, Santen Inc. decided to relocate its office," the company said in a statement.

Santen set up the U.S. clinical and business development operation in January 1993. A business-development office in Irvine will remain open, according to the company.

The loss of one of Napa Valley's second major medical technology company comes after Dey Labs in south Napa was set to shut down last year, a decision that was reversed.