Eyeworld

from an intravenous injection site, Dr. Yanagi and his colleagues have been working on a novel drug deliv- ery system, a nanodevice based on polymeric micelles. Once at the tar- get site, the micelles take advantage of what Dr. Yanagi called the en- hanced permeability and retention (EPR) effect in injured tissue to exit the blood stream and release the therapeutic agent held within the micelle core. Dr. Yanagi and his colleagues have tested the micelles in rat mod- els of choroidal neovascularization (CNV). After injection into the rats' tails, the micelles were found to ef- fectively accumulate in the experi- mental CNV lesions. The micelles can be used to de- liver biological or pharmaceutical agents, enzymes to enhance photo- dynamic therapy, or even DNA as a non-viral vector for gene therapy. The system, said Dr. Yanagi, is already in Phase I for cancer. As the experiments he described indicate, Dr. Yanagi hopes that the system will be used to treat CNV. Editors' note: Dr. Yanagi declared no fi- nancial interests related to the research. Diet, genes, the environment, and the macula The complex interaction of diet, ge- netics, and the environment in the pathophysiology of macular degen- eration is as confusing to ophthal- mologists as it is to patients. Unfortunately, patients expect their doctors to know better. The Macular Degeneration (MD) Foundation held a symposium to try to establish what exactly doctors should tell their pa- tients. The panelists at the sympo- sium—including Johanna M. Seddon, M.D., New England Eye Center, Boston; Paul Mitchell, M.D., University of Sydney, Aus- tralia, and Westmead Hospital, Syd- ney; Anushka Patel, M.D., The George Institute and Royal Prince Alfred Hospital, Sydney; and moder- ator Paul Beaumont, M.D., director, MD Foundation—agreed that there are a few things we now know for certain: smoking increases the risk for macular degeneration; patients should exercise and maintain a nor- mal weight; they should eat more fish, fruit, green leafy vegetables rich in lutein/zeaxanthin, nuts, and extra virgin olive oil; and red meat in- creases the risk for all-cause mortal- ity, as well as death from cancer and cardiovascular disease. However, it quickly became clear that there is a lot that remains uncertain. How do we handle fats in the diet? The panelists agreed that trans-fatty acids are bad and marine omega-3 polyunsaturated fatty acid (PUFA) is good, but what about plant omega-3 PUFA and omega-6 PUFA? What about white meat? Studies say white is better than red, but these studies combined chicken with fish. What about eggs? It is notoriously difficult to study the interaction between diet, genetics, and the environment. For instance, according to Tien Yin Wong, M.D., Singapore National Eye Centre, who was unable to at- tend the symposium but passed in- formation along to Dr. Beaumont, the fact that there is a lack of nutri- tional information for populations in Asia is because every region has its specific dietary patterns; add the complex genetic heritage of popula- tions in the region, as well as the va- riety of environmental conditions and what you have is, basically, a chaotic mess. Still, Dr. Wong offered one piece of information that offers a mod- icum of hope: Chinese populations in the United States have five times higher risk for developing macular degeneration than Chinese popula- tions in China. This one fact suggests that, as Dr. Mitchell put it, it is possible to eat our way out of a genetic risk for MD. Trouble is, as one audience member noted, we don't know how to do it yet. Editors' note: None of the speakers de- clared any financial interests related to their lectures. The 2011 Holmes lecture: Strike back at glaucoma blindness The APAO describes the Holmes lec- ture as the highest award for excep- tional contributions in preventive ophthalmology, especially for the prevention of blindness in the Asia- Pacific region. The lecture honors John Holmes (1911–1989), founding secretary general of APAO. This year, the honor of deliver- ing the lecture was given to Prin RojanaPongpun, M.D., chief of the glaucoma service, and chief glau- coma consultant, Queen Sirikit Insti- tute of Child Health, Ministry of Public Health, Bangkok, Thailand. His lecture was titled, "Strike back at glaucoma blindness." In Thailand, as in many other countries in the Asia-Pacific region, it is common for a surgeon to see a patient for the first time who is al- ready in the late stages of the dis- ease, said Dr. RojanaPongpun. For glaucoma, this isn't so surprising; patients usually only experience symptoms late in the disease. The consequences of this can be devastating; trabeculectomy, which remains the "gold standard" for treating glaucoma, produces unpre- dictable results and often leads to complications directly related to the procedure, more so when it is per- formed late in the disease. Since early treatment is crucial to preserving vision—vision loss from glaucoma is permanent—popu- lation-based screening, said Dr. RojanaPongpun, would be the ideal way to go. Unfortunately, he said, there is no effective method for screening and no universal, cost-ef- fective method for monitoring the progress of treatment. There's only one strategy left: public awareness. Glaucoma detec- tion is most cost effective when it is done at the level of the doctor's clinic. If patients are educated about glaucoma, maybe they'll start hav- ing their eyes checked more regu- larly, early detection can become the norm rather than the exception, and maybe they'll comply better with treatment. Editors' note: Dr. RojanaPongpun has no financial interests related to his lecture. EW MEETING REPORTER 65

• Cover