Ocular risk factors for visually consequential AMD

• Visually consequential AMD in one eye: Visually consequential AMD in one eye is a major risk factor for developing visually consequential AMD in the fellow (i.e. the other) eye.
• Soft drusen: Soft drusen refer to yellow/white deposits visible in the macular area, and which are known to represent risk for visually consequential AMD. Of note, hard drusen (which have distinct edges) are not representative of risk for visually consequential AMD.
• Pigmentary changes at the macula: Hyper- and hypo- pigmentary changes at the macula are known to represent significant risk for visually consequential AMD; hyper-pigmentary changes refer to areas of pigment clumping, whereas hypo-pigmentary changes refer to areas of depigmentation, within the macula.
• Macular pigment: There is a growing body of evidence that macular pigment (which is entirely of dietary origin) may play a role in the prevention, or delay in the onset or progression, of visually consequential AMD. Recent research has shown that people at increased risk of developing visually consequential AMD have low levels of this pigment even before the disease occurs.
• Hypermetropia: Hypermetropia (i.e. long-sightedness) is a suggested risk factor for visually consequential AMD.
• Iris colour: Light iris colour is a suggested risk factor for visually consequential AMD.
• Prior cataract surgery: There is some, albeit conflicting, evidence that prior cataract surgery is associated with increased risk of visually consequential AMD.

Non-ocular risk factors for visually consequential AMD
There are many non-ocular risk factors for visually consequential AMD. There is a growing consensus with regards to the significance of each of these non-ocular risk factors with respect to their contribution to risk for visually consequential AMD.

• Family history of visually consequential AMD: Family history of visually consequential AMD is one of the most important and established risk factors for this condition.  In fact, having a first degree relative (i.e. parent/brother/sister) with visually consequential AMD is believed to increase your risk of developing visually consequential AMD threefold when compared to an individual without such a confirmed family history of disease. 
• Cigarette smoking: Cigarette smoking is one of the most important and established risk factors for visually consequential AMD. The current evidence is broadly consistent across a range of study designs. Indeed, the risk of developing visually consequential AMD is two to three times greater among current smokers when compared with people who never smoked cigarettes.  
• Diet: Current research has shown that diet is an important risk factor for visually consequential AMD. In particular, a diet containing the macular carotenoids is believed to be important in preventing the onset of visually consequential AMD (see AREDS report 22 “Higher dietary intake of lutein/zeaxanthin was independently associated with decreased likelihood of having neovascular AMD, geographic atrophy, and large or extensive intermediate drusen”).
• Antioxidant supplements: Antioxidant supplements have been shown to be beneficial in reducing the progression of non-visually consequential AMD to visually consequential AMD (i.e. preventing AMD that has not yet affected vision from developing into AMD that does affect vision – see AREDS report 9).  Also, there is a growing body of evidence that antioxidant supplements containing the macular carotenoids may be beneficial in terms of preventing or delaying the onset or progression of AMD (see LAST study).
• Ethnicity: White race is associated with increased risk of visually consequential AMD, reflected in the fact that that the prevalence of this disease is far greater in white populations when compared to non-white populations. However, the prevalence of visually consequential AMD is on the increase in non-white populations, probably due to the fact that western lifestyle habits are becoming more common worldwide (e.g. diets deficient in fruit and vegetable intake). 
• Obesity: Obesity is a putative/suggested risk factor for visually consequential AMD. In fact, there appears to be a growing body of evidence in support of the view that obesity is an important determinant for the development of visually consequential AMD.
• Sex: Female sex is a suggested risk factor for visually consequential AMD, and the link between female sex and development of visually consequential AMD is believed to be hormone-related (i.e. oestrogen-related). However, the evidence available is not conclusive, and the greater prevalence of visually consequential AMD in females may be due to the fact that females live longer.
• Cumulative exposure to visible light: Cumulative exposure to visible light is a putative/suggested risk factor for visually consequential AMD. While evidence in support of this notion is lacking, and inconsistent, the majority of studies which have investigated the relationship between cumulative exposure to visible light and risk of developing visually consequential AMD have reported significant associations.
• Cholesterol: High cholesterol is a putative/suggested risk factor for visually consequential AMD. However, the results of various studies investigating a possible link between hypercholesterolaemia and AMD are not conclusive.
• Hypertension: Hypertension (i.e. high blood pressure) is a putative/suggested risk factor for visually consequential AMD. However, the results of studies to date remain inconclusive.

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