AMD is the leading cause of blindness in developed countries, and the third-leading cause in developing countries. Globally, between 20 and 25 million people are affected by AMD, and the World Health Organization (WHO) estimates that eight million people have severe blindness as a direct result of the disease: it is projected that the number of people with some form of AMD will double between now and 2050 (1). Tools to treat AMD are limited. Wet AMD is addressed reasonably effectively with anti-VEGF therapy, lasers and even low-voltage x-ray therapy, but it accounts for only 10 percent of all AMD cases. Very little can be done today to treat the 90 percent of patients with dry AMD, beyond a recommendation to take high doses of vitamin supplements and antioxidants (2). The practical implications of the rise in AMD patient numbers are being felt everywhere. Retina clinics are massively oversubscribed, with specialists often working far longer than their allotted hours to get through the case loads, in part because intravitreal ranibizumab or aflibercept injections are time-consuming, and in many cases, need to be administered monthly.
Improved ways of treating wet AMD that involves fewer clinic visits are needed, whereas novel approaches for dry AMD are therefore a desperate requirement in the near future. To gain an insight into where research into therapies for AMD have been, and where they are going, we decided to analyze clinicaltrials.gov (Box).
Clinicaltrials.gov: its history and why it’s used
This article employs data from clinicaltrials.gov, the US National Institutes of Health’s central clinical trials registry (CTR). Launched in February 2000, it was created in order to foster greater transparency from pharmaceutical companies and clinical research organizations (CROs) against a background of allegations that some companies had been hiding any record of trials that produced poor results. It is the biggest and most well-used of all CTRs; most clinical trials, if registered, are registered there. There have been historic concerns of the quality of some of the earlier records (3), and the fact that not all trials were being registered on a CTR (4), although almost all journals should now refuse to publish results from trials not registered on one (4). Despite these notable caveats, clinicaltrials.gov is the biggest and best, and so The Ophthalmologist mined that registry to understand the historic, and potential trends.We searched clinicaltrials.gov for: (“AMD” OR “age-related macular degeneration”), and exported the entire dataset as tab-separated values, for import into and analysis within Microsoft Excel 2013. Inappropriate records (mostly related to an oncology drug, plerixafor, which has the company name AMD3100) were removed, and the full text of each record examined for additional details to be recorded into the spreadsheet.
References
- A Chopdar, U Chakravarthy, D Verma, “Age Related Macular Degeneration”, BMJ, 326, 485–488 (2003). JS Tan et al., “Dietary antioxidants and the long- term incidence of age-related macular degeneration: the Blue Mountain Eye Study”, Ophthalmology, 115, 334–341 (2008). PMID: 17664009. CD De Angelis et al., “Is this clinical trial fully registered?—A statement from the International Committee of Medical Journal Editors”, N Engl J Med., 352, 2436–2438 (2005). PMID: 12609947. International Committee of Medical Journal Editors: Uniform Requirements for Manuscripts Submitted to Biomedical Journals. www.icmje.org/urm_main.html, accessed August 26th, 2015.
