The number of people who will become visually impaired in the U.S. is expected to be 8 million. In addition to that, another 16 million will have difficulty seeing due to refractive errors such as myopia (nearsightedness) or hyperopia (farsightedness) that can be corrected with glasses or contacts. In 2015, 3.2 million Americans had vision of 20/40 or worse, even with correction. If that isn’t enough, another 8.2 million had vision problems due to uncorrected refractive error.
Yet it’s not all gloom and doom. Research has lead to the development of anti-vascular endothelial growth or anti-VEGF drugs for macular degeneration. These drugs stop the formation of abnormal blood vessels that damage the retina in wet macular degeneration. Macular degeneration is the leading cause of blindness for Americans over the age of 65 and before these drugs came along, not much could be done for people with this condition. Now these drugs have produced good outcomes.
A study funded by the National Eye Institute (NEI) found that after five years, 50 percent of those who were treated with the anti-VEGF drugs had vision of 20/40 or better, 20 percent had 20/200 vision or worse and the rest were between those ranges. These kinds of results were unthinkable just 10 years ago. Prior to anti-VEGF drugs, the best treatment for macular degeneration was photodynamic therapy, in which a drug is injected into a vein and a laser is used to seal a leaking blood vessel. Studies of the photodynamic therapy have shown that after one year, only 15 percent of patients retain 20/40 vision.
Another study was done with two anti-VEGF drugs, Lucentis and Avastin, to treat macular degeneration to see which was more effective in treating the disease. Over 1200 people were randomly assigned one or the other drug either monthly or on an as needed basis. This and later studies showed that these drugs were equal in preserving visual acuity.
Anti-VEGF drugs aren’t just used to treat macular degeneration, however, they are also effective against diabetic retinopathy. A study was done in 2012 with those who received Lucentis. Almost 40 percent of the patients in the study received a monthly injection of 0.3 mg of the drug, and a little over 39 percent recieved a monthly injection of 0.5 mg. Both groups gained 15 letters on a standard eye chart. Another study found that Lucentis combined with laser photocoagulation treatment was more effective than laser treatment alone. In this study, one year after the Lucentis plus laser, close to 45 percent of the patients had 20/40 vision, compared with only 23 percent of the laser only group.
Yet, as great as anti-VEGF drugs are, they don’t seem to stop geographic atrophy in those who have macular degeneration. So, the next step is to find a way to treat this condition. Still, anti-VEGF drugs are another effective tool doctors can use to treat those with macular degeneration and diabetic retinopathy.
Sources:
https://nei.nih.gov/news/pressrelease/visual_impairment_cases_2050
https://nei.nih.gov/news/pressrelease/AMD_before_after_anti-VEGF_drugs
http://macula.org/anti-vegf-therapy
http://www.news-medical.net/life-sciences/Anti-VEGF-Therapies.aspx
http://www.allaboutvision.com/conditions/diabetic-treatment.htm