ReMed Magazine | Sciences de la santé
ReMed Magazine Sciences de la Santé
Clinical assessment
There are three stages of AMD defined in part by the size and number of drusen under the retina . It is possible to have AMD in one eye only , or to have one eye with a later stage of AMD than the other . Early AMD is diagnosed by the presence of medium-sized drusen , which are about the width of an average human hair . Patients with early AMD typically do not have vision loss . Patients with Intermediate AMD typically have large drusen , pigment changes in the retina , or both . Again , these changes can only be detected during an eye exam . Intermediate AMD may cause some vision loss , but most people will not experience any symptoms . In addition to drusen , people with late AMD have vision loss from damage to the macula . There are two types of late AMD : in geographic atrophy ( also called dry AMD ), there is a gradual breakdown of the light-sensitive cells in the macula that convey visual information to the brain , and of the supporting tissue beneath the macula . These changes cause vision loss . In neovascular AMD ( also called wet AMD ), abnormal blood vessels grow underneath the retina . These vessels can leak fluid and blood , which may lead to swelling and damage of the macula . The damage may be rapid and severe , unlike the more gradual course of geographic atrophy . It is possible to have both geographic atrophy and neovascular AMD in the same eye , and either condition can appear first .
Treatment and prevention
Early AMD : currently , no treatment exists for early AMD , which in many people shows no symptoms or loss of vision . A comprehensive dilated eye exam is recommended at least once a year . The exam will determine if AMD is advancing . As for prevention , AMD occurs less often in people who exercise , avoid smoking , and eat nutritious foods including green leafy vegetables and fish . Adopting some of these habits may help keep the patients vision longer . Intermediate and late AMD : researchers at the National Eye Institute tested whether taking nutritional supplements could protect against AMD in the Age-Related Eye Disease Studies ( AREDS and AREDS2 ). They found that daily intake of certain high-dose vitamins and minerals can slow progression of the disease in people who have intermediate AMD , and those who have late AMD in one eye . The first AREDS trial showed that a combination of vitamin C , vitamin E , beta-carotene , zinc , and copper can reduce the risk of late AMD by 25 percent . The AREDS2 trial tested whether this formulation could be improved by adding lutein , zeaxanthin or omega-3 fatty acids . The AREDS2 trial found that adding lutein and zeaxanthin or omega-three fatty acids to the original AREDS formulation ( with beta-carotene ) had no overall effect on the risk of late AMD . However , the trial also found that replacing beta-carotene with a 5-to- 1 mixture of lutein and zeaxanthin may help further reduce the risk of late AMD . Moreover , while beta-carotene has been linked to an increased risk of lung cancer in current and former smokers , lutein and zeaxanthin appear to be safe regardless of smoking status . Here are the ingredients based on AREDS and AREDS2 research :
- 500 milligrams ( mg ) of vitamin C - 400 international units of vitamin E - 80 mg zinc as zinc oxide - 2 mg copper as cupric oxide - 10 mg lutein and 2 mg zeaxanthin
-Colour fundus photograph showing soft , confluent , large drusen in a patient with non neovascular ( dry ) ( AMD ). Corresponding spectral-domain optical coherence tomography ( SD-OCT ) image of the soft drusen . Auto fluorescence image of an eye with areas of confluent drusen .
-Colour fundus photographs of right and left eyes , demonstrating advanced geographic atrophy .
8 ReMed Automne 2017
In intermediate or late AMD , might benefit from taking supplements containing these ingredients . Many supplements have different ingredients , or different doses , from those tested in the AREDS trials . Therefore choosing the appropriate supplement is necessary . Some recent studies have claimed that , depending on genotype , some patients will benefit from AREDS supplements and others could be harmed . These claims are based on a portion of data from the AREDS research . The US NEI investigators have done comprehensive analyses of the complete AREDS data . Their findings to date indicate that AREDS supplements are beneficial for patients of all tested genotypes . Based on the overall data , the American Academy of Ophthalmology does not support the use of genetic testing to guide treatment for AMD .
ReMed 2017 | Numéro 2 | 5