Macula Risk

Macula Risk is a prognostic DNA test intended for patients who are over 65 and have a diagnosis of early or intermediate AMD. Using the complete combination of AMD genes, and smoking history, Macula Risk identifies those most likely to progress to advanced AMD with vision loss. The patient sample is a cheek swab taken in office.
Early detection and treatment of AMD is critical for the prevention of blindness. Frequent monitoring is recommended for ‘at risk’ patients with early or intermediate AMD (drusen) to detect CNV at a treatable stage.
There are five risk levels (See Table 1) defined using Macula Risk testing. Risk levels 3, 4 and 5 represent 20% of people. They have a higher than average risk for vision loss from AMD.
Insert Table 1 here
CNV: Choroidal neovascularization
GA: Geographic atrophy
Individuals who are at increased risk (Macula Risk Level 3, 4 and 5) may benefit from:
• An increased frequency of comprehensive eye examinations
• Disease education and possibly ‘at-home’ Amsler Grid testing
• Preventative eye vitamin therapy
• Early diagnosis and treatment of ‘Wet’ AMD with effective therapies such as ranibizumab (trade name Lucentis), bevacizumab (trade name Avastin) & pegaptanib (trade name Macugen)
Genes tested in Macula Risk test
Early work demonstrated that a family of immune mediators was plentiful in drusen . CFH is an important inhibitor of this inflammatory cascade and a disease-associated polymorphism in the complement factor H (CFH) gene strongly associates with AMD . Thus an AMD pathophysiological model of chronic low grade complement activation and inflammation in the macula has been advanced Lending credibility to this has been the discovery of disease-associated genetic polymorphisms in other elements of the complement cascade including complement component 3 (C3) .
The role of retinal oxidative stress in the etiology of AMD by causing further inflammation of the macula is suggested by the enhanced rate of disease in smokers and those exposed to UV irradiation . The mitochondria are a major source of oxygen free radicals that occur as a byproduct of energy metabolism. Mitochondrial gene polymorphisms, such as that in the ND2 molecule, predicts wet AMD .
A powerful predictor of AMD is found on chromosome 10q26 at LOC 387715. An insertion/deletion polymorphism at this site reduces expression of the ARMS2 gene though destabilization of its mRNA through deletion of the polyadenylation signal (15, 16). ARMS2 protein may localize to the mitochondrial and participate in energy metabolism, thought much remains to be discovered about its function.

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