Coherent, Inc. Receives U.S. Approval for Use of Lasers for Late Stage Lung Cancer Treatment.

SANTA CLARA, Calif.--(BW HealthWire)--Dec. 23, 1998--Coherent, Inc. (Nasdaq:COHR) today announced the U.S. Food and Drug Administration's clearance of Photofrin(R) (porfimer sodium) for the palliative treatment of non-small cell late stage lung carcinoma. Photofrin is a photodynamic drug that utilizes Coherent's Lambda Plus(R) dye laser for activation. Photodynamic therapy (PDT) utilizes the combination of a light-activated drug and a specific wavelength of laser light to activate the drug. When the drug is activated by the laser light, a reaction is triggered that kills the host tumor cells.

Bernard Couillaud, Coherent's President and CEO said, "Photodynamic therapy presents us with an opportunity to treat large numbers of people with cancer and in the future with potential treatments in ophthalmology and autoimmune disease."

An estimated 171,500 Americans were diagnosed with lung cancer this year, the majority of which were in later stages of the disease. Approximately 20,000 to 25,000 of these patients will be candidates for this treatment. Earlier this year the FDA cleared Photofrin with the Lambda Plus for the treatment of early stage non-small cell lung carcinoma. The first clearance for this drug and laser combination was for the treatment of late stage esophageal cancer in 1995.

Photofrin is produced by QLT PhotoTherapeutics Inc. (NASDAQ:QLTIF and TSE:QLT) a world leader in the development and commercialization of proprietary pharmaceutical products for use in photodynamic therapy.

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The statements in this press release that relate to future plans, events or performance are forward-looking statements that involve risks and uncertainties, including risks associated with uncertainties related to currency adjustments, contract cancellations, manufacturing risks, competitive factors, uncertainties pertaining to customer orders, demand for products and services, development of markets for the Company's products and services and other risks identified in the Company's SEC filings. Actual results, events and performance may differ materially. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. The Company undertakes no obligation to release publicly the result of any revisions to these forward-looking statements that may be made to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events.

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Founded in 1966, Coherent, Inc. is a Standard & Poor's SmallCap 600 company and a world leader in the design and manufacture of lasers and systems for medical, scientific and commercial applications. Please direct any questions to Robert J. Quillinan, Executive Vice President and Chief Financial Officer at [phone]. For more information about Coherent, visit our Web site at http://www.cohr.com for product and financial updates. To receive a full text copy of this press release by fax, please call 877/329-2647.