What is AMD?
Age-related Macular Degeneration (AMD) is a devastating retinal degenerative disease that affects the macula, the part of the eye that provides sharp, central vision. Those who suffer from this progressive disease are unable to drive, read or recognize faces. In AMD, vision loss is the result of the death or dysfunction of retinal pigment epithelial cells (RPE) that provide nutrients and support to the light sensing photoreceptor cells in the eye.
There are two forms of AMD: wet and dry. In the wet form of macular degeneration (known as choroidal neovascularization or CNV), abnormal blood vessels grow under the macula and retina. Fluid from leakage of these blood vessels accumulates and cause vision loss or distorted vision. In dry AMD (non-neovascular form) small yellow deposits form beneath the retina, which can ultimately lead to geographic atrophy (GA) or the advanced form of dry AMD. Dry AMD is the most prevalent form of macular degeneration and can be stable for many years without vision loss. Patients diagnosed with GA have severe loss of vision and a tangible impact on quality of life. To date, there is no cure or known treatment options for GA.
Who is at Risk?
In general the global burden of AMD remains substantial as a result of the aging population. Globally, the projected prevalence of AMD in 2020 is 196 million, increasing to 288 million in 2040. The main risk factors for AMD are age and race. Among Americans of European decent, the prevalence of AMD is projected to rise to nearly 5.44 million by 2050 according to reports from the National Eye Institute. A significant increase in the rate of AMD amongst minority populations has also been observed. Most notably, a six-fold rise of AMD has been reported in persons of Hispanic decent.
Other risk factors for AMD include positive family history, smoking, hypertension, high cholesterol and obesity.
How is AMD Diagnosed?
Pay attention to the signs of early disease including distorted vision and your risk factors for developing AMD. Please make an appointment to see your eye care specialist at least once a year if you are over 40 years of age, if you are at risk as a result of ocular and medical history, family history, age, or race and especially if you are noticing vision loss. Your ophthalmologist or optometrist will conduct a comprehensive eye exam, which will include dilated eye exams, visual acuity, and optical coherence tomography (OCT). Following a thorough assessment, your physician will work closely with you to determine the best course of action.
Are There Treatments for AMD?
In general there is no known cure for AMD. However, for the wet form of AMD, drug treatment options include anti-VEGF (vascular endothelial growth factor) therapies. Such therapies reduce the level of VEGF, a protein known to stimulate abnormal blood vessel growth in the retina and macula. These drugs are administered as injections directly into the eye.
Thus far there is no FDA approved treatment available for dry AMD. USC vision researchers, Dr. Mark Humayun and David Hinton, funded by the California Institute for Regenerative Medicine, have recently developed a novel stem cell-based therapy for the treatment of advanced dry AMD. The treatment consists of a patch of RPE cells derived from stem cells that is grown onto a polymer scaffold and implanted behind the diseased portion of the eye. A clinical trial is currently underway to evaluate this potential treatment at USC and is led by Assistant Professor of Clinical Ophthalmology, Dr. Amir Kashani. Enrollment in the phase I/IIa clinical trial is ongoing for this stem cell-based treatment.
To learn more, please visit: https://clinicaltrials.gov/ct2/show/NCT02590692?term=subretinal+implant+AMD +dry&rank=1.
- Wong WL, Su X, Li X, et al. Global Prevalence of Age-Related Macular Degeneration and Disease Burden Projection for 2020 and 2040: A Systematic Review and Meta-Analysis. Lancet Glob Heal. 2014;2(2):106-116. doi:10.1016/S2214-109X(13)70145-1.
- Congdon N, O’Colmain B, Klaver CC, et al; Eye Diseases Prevalence Research Group. Causes and Prevalence of Visual Impairment Among Adults in the United States. Arch Ophthalmol. 2004;122(4):477-485.
- Varma R, Fraser-Bell S, Tan S, Klein R, Azen SP; Los Angeles Latino Eye Study Group. Prevalence of Age-Related Macular Degeneration in Latinos: The Los Angeles Latino Eye Study. Ophthalmology. 2004;111(7):1288-1297.