Age-related macular degeneration (AMD) is the leading cause of irreversible visual impairment in patients over the age of 60 years. AMD and cardiovascular disease are both age-related illnesses; given the similarity between the pathogenesis of atherosclerosis and AMD-related drusen, there have been numerous studies that have implicated a possible role of modifiable cardiovascular risk factors in the pathophysiology of AMD.
It is speculated that the hemodynamic abnormalities associated with high blood pressure lead to reduced choroidal blood flow, causing a disturbance in vascular homeostasis and ischemia, leading to activation of the renin-angiotensin system and contributing to AMD.
Diabetes mellitus is known to be a major risk factor for cardiovascular disease and also requires ophthalmic care due to the risk of diabetic retinopathy. Considering that vascular endothelial growth factor plays a role in the pathophysiology of both diabetic retinopathy and AMD, studies have been conducted to examine the association between diabetes and AMD. Similar to other risk factors, hyperglycemia is implicated in the pathogenesis of AMD due to oxidative stress that results from homeostatic disturbance of the retina and induction of the inflammatory cascade.
Associations between cardiovascular disease and AMD have been studied extensively. Some modifiable cardiovascular disease risk factors such as exercise and body mass index have been found to be associated with AMD in a similar trend as they are with cardiovascular disease; however, the data for such relationships is limited.
Age and smoking are the most consistently proven cardiovascular disease risk factors found to be associated with AMD, with findings for the other factors often being contradictory or difficult to interpret. To date, smoking has been identified as the single most important modifiable risk factor for late-stage AMD, and ophthalmologists and other physicians are encouraged to emphasize the importance of smoking cessation in attempting to reduce the risk of visual loss and blindness from this disease. Patients are encouraged to realize the importance of smoking cessation.
While it is challenging to predict whether patients with cardiovascular disease later develop AMD based on current literature, the available data raises awareness of the possible association between two very common conditions in the current aging patient population, thus influencing ophthalmic practice. A healthy lifestyle plays a crucial role and impacts the metabolic risk factors such as diabetes and hypertension on not only on their overall health, but also their ocular health and vision.
Adapted from article by Saumya M Shah, BS, and Sophie J Bakri, MD