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44 EW GLAUCOMA August 2013 February 2011 Pharmaceutical focus Early lessons learned from key trials about glaucoma medical therapy T here's no denying it—from OHTS to CIGTS to AGIS, GLT, SLT, and more, this alphabet soup of multicenter, randomized clinical trials concerning glaucoma have played by Maxine Lipner EyeWorld Senior Contributing Writer an important role in defining treatment, according to Steven L. Mansberger, MD, vice chair and director of the glaucoma service, Devers Eye Institute, Portland, Ore. "They've guided us in so many things that we do in glaucoma," Dr. Mansberger said. Indeed, before most of these trials were performed there was a great deal of skepticism as to whether treating glaucoma mattered at all, said Michael Kass, MD, Bernard Becker professor and chair, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis. "A number of clinicians and scientists pointed out that we lacked the kind of gold-standard clinical proof that medical treatment was effective in either delaying or preventing the progress of the disease," Dr. Kass said. OHTS and other notes In the OHTS (Ocular Hypertension Treatment Study), the goal was to try to answer the question of whether practitioners could prevent or delay the onset of glaucoma in those with elevated intraocular pressure, Dr. Kass explained. "We wanted to know, by giving these patients eye drop therapy, can we reduce their incidence of developing glaucoma?" he said. In the trial, participants were randomized to receive medical treatment or for simple observation. "It became quite clear that medical treatment did reduce the incidence of open-angle glaucoma for both structural and functional damage," Dr. Kass said. The immediate goal of OHTS, as well as other studies such as CIGTS (Collaborative Initial Glaucoma Treatment Study) and AGIS (Advanced Glaucoma Intervention Study), was to lower pressure, according to L. Jay Katz, MD, director of the glaucoma service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia. The pressure was lowered in these trials by differing amounts. For example, in OHTS this was 20%, while in CIGTS an individualized formula for each patient was used. With CIGTS the patient's change in treatment was triggered by a change in the field primarily, noted George Spaeth, MD, Esposito research professor, Wills Eye Institute, and professor of ophthalmology, Thomas Jefferson Medical College. "It showed that if you monitor fields carefully and regulate pressure according to an algorithm for setting a particular pressure for each individual, you can be effective in preventing patients from getting worse," he said. The 20% figure for IOP reduction espoused by the OHTS trial, Dr. Mansberger pointed out, is one that