Over the past decade, prolific basic science and clinical research in all areas of vision care have led to multiple advances in clinical research.
Editor's Note: Ophthalmology Times continues its observance of Ophthalmologist Appreciation Month. In this article, for insights on some of the most notable advancements in vision-care research over the past decade, Ophthalmology Times interviewed several members of the Association for Research in Vision and Ophthalmology (ARVO) Board of Trustees.
In the second article (See "Lenses, frames and low vision: Vision care has come a long way"), Ophthalmology Times focuses on the innovative changes in the areas of lenses, frames, and low vision.
Over the past decade, prolific basic science and clinical research in all areas of vision care have led to multiple significant advances in clinical management.
There is no doubt that the introduction of anti-vascular endothelial growth factor (VEGF) therapy is the most important development in the field of retinal disease during the past decade. However, progress is also being made in numerous other areas that may be expected to affect patient care positively in the future, said William F. Mieler, MD, ARVO Trustee for the retina section, and professor and vice chairman, Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago.
"Looking back to the year 2000, retinal thermal laser therapy was the only option for treating choroidal neovascularization (CNV) associated with age-related macular degeneration (AMD) and other conditions," Dr. Mieler said. "However, it was effective only for limiting disease progression and only in some patients. Subsequently, photodynamic therapy (PDT) emerged, and it was shown to be more beneficial, though far from optimal."
The FDA approval of pegaptanib sodium (Macugen, Eyetech) in 2004 launched the era of targeted anti-VEGF therapy for exudative AMD. Pegaptanib sodium received an indication for treating any AMD-related subfoveal choroidal neovascular lesion based on clinical trial evidence showing its superiority to placebo for preventing vision loss.
Treatment for exudative AMD, however, was changed dramatically by ranibizumab (Lucentis, Genentech) and off-label use of bevacizumab (Avastin, Genentech), which represented the first treatment modalities that provide clinically significant improvement in vision for a sizeable proportion of patients, Dr. Mieler said.
"As of today, treatment of CNV with these agents remains the gold standard," he added.
Research with ranibizumab is continuing, including investigations to refine treatment protocols for exudative AMD with the goal of reducing the burden of frequent intravitreal injections and to expand its indications for the management of other ocular diseases. In fact, ranibizumab was approved recently by the FDA for the treatment of macular edema secondary to retinal vascular occlusion (another leading cause of retinal disease-related vision loss), and preliminary results are promising in studies evaluating its use for the treatment of diabetic retinal disease.
Other pharmacologic agents for the treatment of AMD are in the pipeline as well, including anti-VEGF drugs that have a longer half-life than ranibizumab, as well as numerous novel molecules that target both the wet as well as the dry form of AMD. However, even in the best-case scenario, it will be years before any of these treatment modalities enter the realm of clinical practice, Dr. Mieler said.
Improvements in diagnostic imaging equipment also have had an important impact on care of patients with retinal disease, and in particular, the availability of spectral domain optical coherence tomography (SD-OCT) devices that provide much higher resolution than previous technology.
"The evolution in OCT technology has helped clinicians with disease diagnosis as well as improved our ability to monitor disease progression and response to therapy," Dr. Mieler said.
There also have been important advances in the understanding of the molecular genetics of retinal diseases, including identification of modes of inheritance and early application to disease diagnosis.
"So far, developments in molecular genetics of retinal diseases have had limited direct application to patient care, but this is an area where we can expect rapid advances and major breakthroughs in the future, not only for improving diagnosis, but also for developing better treatments," Dr. Mieler said. "By understanding the molecular basis of inherited diseases, we can look forward to applying that knowledge to design targeted therapy able to modify the course of the disease process."
For patients with retinal diseases affected by vision loss that is not amenable to improvement by pharmacologic therapy or existing surgical options, there also have been encouraging advances in research focusing on the development of retinal prostheses and retinal transplantation. A number of groups nationally and internationally are working in these areas, and considering the progress being made, there is good reason to believe that these modalities will become a viable option for providing some degree of functional vision rehabilitation, according to Dr. Mieler.
"While the impact of this research on overall patient care is less than that associated with ongoing research in the area of pharmacologic intervention and even molecular genetics, it is an exciting and important area as well," he said.