Background: Age-related macular degeneration (AMD) is a progressive degenerative disease
of the macula and is the leading cause of visual impairment in the elderly population worldwide.
The two advanced forms of AMD are geographic atrophy and choroidal neovascularization (CNV)
which are the major causes of visual loss in AMD patients. Clinically effective therapy for CNV is
now available but is limited by the need for repeated intravitreal injections of anti-angiogenic agents.
There is still no effective treatment for geographic atrophy. Earlier concepts on AMD therapy were
confined to local ocular therapies. However, recent evidences show that the complement system, inflammatory
response and oxidative stress level are altered in the systemic circulation of AMD patients.
Meanwhile, within regenerative medicine, stem cell therapy is effectively alleviating these systemic changes in
multiple diseases. These findings have provided new insight into the pathophysiology and subsequent potential for clinical
interventions in AMD.
Methods: This review article will first summarize the pathophysiology of AMD and then describe the systemic disorders
associated with AMD. In addition, the characteristics of mesenchymal stem cells (MSCs) in regenerative medicine and its
potential therapeutic effect for systemic disorders will also be discussed.
Results: AMD is an oxidative stress and inflammation-related disease affecting the RPE and photoreceptor cells of the
macula. It is not only a localized eye disease, but also a disease affected by the systemic status of the patient. There is
good evidence to show the influence of systemic factors in the pathogenesis, including complement system, inflammation,
oxidative stress and angiogenic factors. Since MSCs possess the paracrine effects of anti-oxidation, anti-inflammation and
immunomodulation, systemic administration of MSCs could theoretically alter the systemic influence on AMD progression.
Currently, there are 3 MSC clinical trials on AMD, which locally apply bone marrow and adipose tissue-derived
MSCs to supply neurotrophic factors to the microenvironment.
Conclusion: MSCs hold promises for treating the systemic conditions associated with AMD. The anti-inflammatory and
anti-oxidative effects of MSCs are desirable and be developed as a potential therapeutic strategy against AMD for clinical
treatment in the future.