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Combined therapy appears effective in treating retinal vascular disease
Agents and targeted photocoagulation produce surprising benefits.
A combined treatment regimen of anti-VEGF injections and targeted retinal photocoagulation may be effective for patients with retinal vascular diseases, according to a researcher at the University of California, Los Angeles.
Steven D. Schwartz, MD, and colleagues performed a retrospective chart review of about 40 patients with diabetic retinopathy or retinal vein occlusion who were treated with anti-VEGF injections and targeted photocoagulation and were not enrolled in another study.
“We felt that a number of them did surprisingly well, both in terms of some visual gain and in terms of decreasing the necessity for repeat injections,” Dr. Schwartz told Ocular Surgery News in a telephone interview.
The patients were treated off-label with standard doses of Avastin (bevacizumab, Genentech), Lucentis (ranibizumab, Genentech) or Macugen (pegaptanib sodium, OSI Eyetech/Pfizer). Laser treatment was conducted with the PASCAL Photocoagulator (OptiMedica) and targeted toward areas of retinal ischemia.
“We had patients who had remarkable diminution of macular edema, and we had patients with remarkable regression of neovascularization at the edges of these ischemic areas,” he said.
Targeting laser treatment
Dr. Schwartz and colleagues originally wanted to know whether their use of the new wide-angle P200MA imaging device (Optos) was having an effect on the way they were treating patients. They had been using a prototype of the technology at UCLA for 2 years. The machine was introduced at the 2007 American Society of Retina Specialists annual meeting and released commercially in March.
They found that the angiograms helped them distinguish between healthy and damaged areas of the retina.
“This treatment with the angiogram allows us to discriminate between the retina, where we hypothesize that the VEGF is being made, and the areas where the retina’s still viable,” he said.
“The basic science of VEGF is that it seems to be produced, at least in retinal vascular disease, by hypoxic areas of retina, areas where there’s poor or no blood flow,” Dr. Schwartz said.
By identifying these ischemic areas and targeting them with photocoagulation, the physicians were able to “decrease VEGF production while, at the same time, sparing a lot of the destructive effects of the laser to the healthy retina,” he said.
Treatment adjustments
Dr. Schwartz said some patients responded to laser treatment of the ischemic areas only. A better response was seen in patients treated in a slightly larger area.
“We expanded the treatment to about two or three disc areas out in a disc-area wide swath along the edges of the ischemic areas, as long as it wasn’t in the macula,” he said.
“Once we treated this sort of intermediate zone adjacent to the ischemia, as well as the ischemia, we were able to get the effect with targeted retinal photocoagulation that we believe may rival the effects of panretinal [photocoagulation],” Dr. Schwartz said.
Typically, patients received the injection first, followed by laser treatment. However, Dr. Schwartz said the order of treatment and time between treatments varied among patients.
The future
The combination of anti-VEGF injections and targeted photocoagulation may be effective because existing VEGF is treated by the injection and new VEGF production is addressed by the laser, Dr. Schwartz said.
“You’re restoring a homeostasis and that’s the idea of combination therapy; it should be synergistic,” he said.
The researchers observed no adverse events that were “outside the typical spectrum that one experiences with either the laser itself or the injection itself,” Dr. Schwartz said.
However, he stressed that the review was retrospective and uncontrolled. He also noted that the patient group was heterogeneous.
“There are certain subsets of patients within these conditions that seem to respond incredibly well to just a little bit of treatment, so it’s hard to know without a control group who’s going to get better anyway,” he said.
Dr. Schwartz and other physicians are preparing for prospective clinical trials to evaluate the treatment combination. Additionally, Thomas R. Friberg, MD, was scheduled to present retrospective data at the Association for Research in Vision and Ophthalmology annual meeting.
Dr. Schwartz noted that the retrospective data remain significant because of the connection to current practice. “It’s a real world, retrospective look because this is what is happening,” he said. “People are combining therapies.”
For more information:
- Steven D. Schwartz, MD, can be reached at Jules Stein Eye Institute, University of California, Los Angeles, 100 Stein Plaza, Los Angeles, CA 90095; 310-206-7474; fax: 310-825-3350; e-mail: schwartz@jsei.ucla.edu. Dr. Schwartz is on the scientific advisory board for Optos and OptiMedica.
- Jessica Loughery is an OSN Staff Writer who covers all aspects of ophthalmology.