ENLIGHTENMENT |
DISEASE SPOTLIGHT
treatable with current technology and understanding of the advancement of the disease.
Clinical signs and symptoms AMD has two detectable stages, early and late stage, or it can also be differentiated in another way: exudative or neovascular (wet) AMD and geographic (dry) AMD. The majority of treatments are directed at the wet stage.¹ Seen in older populations, the disease’s development in a patient is dependent on a number of factors. The three main risk factors for AMD are age, genetic predisposition and consumption of nicotine.² AMD is primarily found in patients over the age of 65. According to Wong et al., “Age-related macular degeneration accounts for 8.7% of all blindness worldwide and is the most common cause of blindness in developed countries.” Developed countries have less instances of preventable blindness among young people; however, as populations in developing countries age, the occurrence of AMD increases.³
Spotlight on Age-related Macular Degeneration by Jillian Webster
As optometrists are often the first to catch sight-threatening disease, in each issue of COOKIE, we’ll shine a spotlight on one ophthalmic condition. In this issue we take a look at age-related macular degeneration, including the clinical signs and symptoms and treatment options.
A
ge-related macular degeneration (AMD) has been increasing in prevalence as the world’s population gets older. It’s directly attributable to vision loss and poses significant pressure on public health. AMD is recognized as a multifactorial disease, with the complement system under heated discussion recently.¹
The factors that contribute to the development of AMD are still being tested and doctors are improving theories with each clinical trial — for example, there is evidence that AMD is brought on by certain genetic and lifestyle factors. Though there are a number of trials and theories regarding treatment, many AMD cases are not
Diagnosing AMD can be difficult. The early stages of AMD are asymptomatic, especially if the fovea, a tiny pit in the retina that provides clear vision, is not yet affected. In general, AMD is characterized by a gradual loss of central vision due to photoreceptor cell degeneration in the macula. The patient should be asked if they are experiencing metamorphopsia, or distorted vision, as this could imply macular disease. Once a patient begins to experience distorted vision, for example, a normally straight line such as a window pane or street line appears askew — it is necessary for the individual to undergo ophthalmological analysis. In AMD, the natural function of the retinal pigment epithelium (RPE) is disturbed. The RPE is a single layer of mature or post-mitotic cells that regulates how the retina receives nutrients. It is likely that the aging of the REP is strongly correlated with the development of AMD.4 AMD is characterized by the accumulation of retinal waste products called drusen underneath the RPE. Drusen is a sign
| May 2021
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