SalutarisMD is currently conducting a prospective, single-arm, open-label, safety, usability and tolerability trial of Strontium 90 (Sr90) beta radiation episcleral brachytherapy in subjects receiving anti-VEGF therapy for the treatment of neovascular Age-related Macular Degeneration (nAMD) lesions.
Wet-AMD – Facts and information
Age-Related Macular Degeneration (AMD) is the primary cause of vision loss in developed countries for individuals 65 and older and it accounts for 8.7% of vision loss worldwide.2,3 AMD affects more than 10 million Americans, which is more than glaucoma and cataracts combined.1
Macular degeneration occurs with the breakdown of the Macula, a portion of the back of the eye located in the center of the Retina. Details of incoming images are centrally focused by the Macula before being sent to the brain for processing. Progressive deterioration of the macula causes the center of images to appear blurry or wavy, with potential for complete loss of central vision.1
The projected number of individuals worldwide with AMD for 2020 is 196 million and is suspected to increase to 288 million in 2040.2
There are two types of Macular Degeneration, differing in their mechanism of causing macular deterioration.
“Dry” AMD affects 85%-90% of people with AMD while “Wet” AMD makes up the remaining 10-15%. Although much less prevalent, 80% of vision loss by AMD is by wet AMD.1
Dry AMD occurs with the thinning and drying out of the Macula, a result of the formation of yellow deposits called Drusen.1 Almost all individuals over 50 have developed at least a small amount of this deposit in one or both eyes, but only large deposits put individuals at risk for developing AMD.1,5
“Wet” AMD occurs with the growth of abnormal blood vessels under the retina and macula. Leakage or bleeding from these blood vessels causes the macula to lift up from the retina, bulging out rather than lying flat.1,5 This abnormal position results in deterioration of central vision which can be quick and severe.
Stages of AMD are classified by severity of symptoms. AMD is usually found during eye exams, as symptoms are not always noticeable. 1
- Early Stage: Most do not experience vision loss.
- Intermediate Stage: Some vision loss may occur but there may also be no noticeable symptoms. Imaging to look for changes in retinal pigment or appearance of large deposits categorize patients into this stage.
- Late Stage: Individuals experience noticeable loss of central vision.
Exact causes of AMD are not fully understood, but many different risk factors have been identified. 1,5
Risk increases with factors of:
- Age, as AMD is most likely to occur in those 55 and older
- Sunlight exposure
When risk factors are present and one eye has wet AMD, the five-year risk of developing wet AMD in the second eye is 87%, whereas if no risk factors are present, the risk is 7%.1
- American Macular Degeneration Foundation. Available at: https://www.macular.org/what-macular-degeneration. Accessed June 27th, 2018.
- Wong, W. L., Su, X., Li, X., Cheung, C. M. G., Klein, R., Cheng, C. Y., & Wong, T. Y. (2014). Global prevalence of age-related macular degeneration and disease burden projection for 2020 and 2040: a systematic review and meta-analysis. The Lancet Global Health, 2(2), e106-e116.https://www.thelancet.com/journals/langlo/article/PIIS2214-109X(13)70145-1/fulltext
- Klein, R., Peto, T., Bird, A., & Vannewkirk, M. R. (2004). The epidemiology of age-related macular degeneration. American journal of ophthalmology, 137(3), 486-495. https://www.ajo.com/article/s0002-9394(03)01509-5/abstract?code=ajopht-site
- Storey, P., Hark, L., & Haller, J. A. (2014). Age-related macular degeneration: an overview. In Handbook of Nutrition, Diet and the Eye (pp. 11-20). https://www.sciencedirect.com/science/book/9780124017177
- Carter, M. Age-related Macular Degeneration : Prevalence, Risk Factors and Clinical Management. New York : Nova Science Publishers, Inc, 2015. (Eye and Vision Research Developments). ISBN: 9781634833295. https://books.google.com/books/about/Age_Related_Macular_Degeneration.html?id=40LhsgEACAAJ