ISTA Pharmaceuticals Announces VITRASE(R) Spreading Agent and Adjunct Clinical Data Presentations for Fall 2005

IRVINE, Calif., Sept. 19 /PRNewswire-FirstCall/ — ISTA Pharmaceuticals, Inc. today announced its Fall 2005 schedule for presenting clinical data on its product, Vitrase(R) (Ovine Hyaluronidase), which is currently FDA approved for use as a spreading agent for hypodermoclysis and as an adjunct in subcuteanous urography. Details regarding the clinical presentations are provided below:

   Ophthalmic Anesthesia Society (OAS) 19th Annual Meeting   Chicago, Illinois — September 23-25, 2005   

Evaluation of preservative-free, highly purified hyaluronidase ovine (Vitrase(R)), 200 USP units/mL, as an adjuvant to increase the absorption and dispersion of other injected drugs prior to ocular surgery

   American College of Clinical Pharmacy (ACCP) 2005 Annual Meeting   San Francisco, CA — October 23-26, 2005    October 24, 2005  

Abstract No. 6396 — Lack of hypersensitivity reactions to hyaluronidase ovine (Vitrase(R))

October 25, 2005

Abstract No. 6423 — Retrobulbar block: the role of Vitrase(R) (hyaluronidase ovine) as an adjuvant to reduce the time required between injection of anesthetic and surgical incision

“We are very excited to announce the upcoming schedule of presentations relating to Vitrase as a spreading agent at major, clinically oriented meetings this fall,” stated Vicente Anido, Jr., Ph.D., President and Chief Executive Officer of ISTA Pharmaceuticals. “Each of these poster or podium presentations will provide further confirmation of the safety and efficacy of Vitrase, the only purified, preservative-free spreading agent and adjunct on the market. We believe that Vitrase’s demonstrable safety record is due to its purity and the fact that this product is formulated without the preservative agent thimerosal, an organomercurial which is broadly implicated in neurotoxicity and has been the subject of intense debate in the health sciences community and regulatory agencies for some time.”

Dr. Anido continued, “We have previously reported that Vitrase has shown 0% incidence of allergic hypersensitivity in over 1100 patients, which is testimony to the quality of our sourcing and manufacturing of this breakthrough product. In addition, studies of Vitrase in retrobulbar block have shown pain-free surgery for most patients, with 95% reporting no ocular pain during the procedure. The presentations scheduled this fall will provide further confirmation of these findings, and we will announce details of these data at the time of their presentation. Overall, we believe that, given the same or superior results in terms of activity and safety, physicians will use the most convenient and cost-effective product as a spreading agent, and we further believe that we have demonstrated and will continue to demonstrate that Vitrase fits this profile.”

Further, Andrew Iwach, M.D., an Associate Clinical Professor of Ophthalmology at the University of California at San Francisco, added that “Vitrase has improved the surgical experience. The speed at which Vitrase works to facilitate anesthesia makes my pre-op procedures more efficient and allows for a more efficient operating environment while helping to increase the comfort of my patients.”

ABOUT VITRASE(R)

ISTA’s Vitrase(R) is a proprietary formulation of highly purified ovine hyaluronidase. In May 2004, the FDA approved Vitrase(R) in a lyophilized 6200 USP Units multi-purpose vial for use as a spreading agent; a 200 USP Units/mL vial in sterile solution for use as a spreading agent was approved in December 2004. FDA’s approval of Vitrase for use as a spreading agent in May 2004 removed hyaluronidase from the FDA’s drug shortage list where it had been listed since 2001.

In addition to its approval for use as a spreading agent, for hypodermoclysis and as an adjunct in subcuteanous urography, Vitrase(R) has been studied for the treatment of vitreous hemorrhage. A New Drug Application, or NDA, was filed for the treatment of vitreous hemorrhage in 2002 and an approvable letter for that NDA was received in 2003. In the letter, the FDA cited issues primarily related to the sufficiency of the efficacy data submitted with the NDA. The FDA requested additional analysis of the existing data and an additional confirmatory clinical study based upon that analysis. Vitrase(R) has also been studied for the treatment of diabetic retinopathy.

ABOUT ISTA

ISTA is a specialty pharmaceutical company focused on the development and commercialization of unique and uniquely improved ophthalmic products. ISTA’s products and product candidates seek to address serious diseases and conditions of the eye such as dry eye, vitreous hemorrhage, diabetic retinopathy, hyphema, glaucoma, ocular pain and inflammation. Building on this pipeline, ISTA’s goal is to continue its growth as a specialty pharmaceutical company by acquiring complementary products, either already marketed or in late-stage development. For more information, please visit the company’s Web site at http://www.istavision.com/

Any statements contained in this press release that refers to future events or other non-historical matters are forward-looking statements. ISTA disclaims any intent or obligation to update any forward- looking statements. Such statements are based on ISTA’s expectations as of the date of this press release and are subject to risks and uncertainties that could cause actual results to differ materially. Important factors that could cause actual results to differ from current expectations include, among others such risks and uncertainties as detailed from time to time in ISTA’s public filings with the U.S. Securities and Exchange Commission, including but not limited to ISTA’s Annual Report on Form 10-K for the year ended December 31, 2004 and ISTA’s Quarterly Reports on Form 10-Q for the periods ended March 31, 2005 and June 30, 2005.

ISTA Pharmaceuticals, Inc.

CONTACT: Vince Anido, +1-949-788-5311, vanido@istavision.com, or LaurenSilvernail, +1-949-788-5302, lsilvernail@istavision.com, both of ISTAPharmaceuticals; or Justin Jackson (Media), jjackson@burnsmc.com, or LisaBurns, or Laura Siino (Investors), lsiino@burnsmc.com, +1-212-213-0006, all ofBurns McClellan for ISTA Pharmaceuticals

Web site: http://www.istavision.com/