Age-Related Macular Degeneration

Introduction

Age-related degeneration leads to the progressive lesion of the macula, which is the central and especially important part of the eye retina. This process appears to be the major cause of vision loss among people aged over 65, according to the Centers for Disease Control and Prevention (as cited in Age-Related Macular Degeneration: What You Should Know 1). The macula consists of light-sensing cells, which are damaged by age-related macular degeneration (AMD) (Lee et al. 5). As a result, the center of vision becomes less sensitive to the light, and consequently, darker and distorted. Therefore, this disease presents a pressing concern and requires further exploration. This way, the purpose of this paper is to describe the current understanding of this disease and its progression, cover the imaging technologies applied for AMD exploration, review the treatment, risk, and genetic factors.

Diseases Progression

Today, scientists distinguish two types of AMD, which are dry and wet ones. The dry form implies thinning of the macular tissue during the cells disappearing (Age-Related Macular Degeneration: What You Should Know 1). Both eyes can incur a disease of this type at the same time. The wet form is a more severe condition, and as stated in ‘Age-Related Macular Degeneration: What You Should Know’, “About 10 to 20 percent of cases progress within five years to wet AMD” (1). This type is followed by blood vessels appearing behind the macula and pouring fluid into it, which leads to irreversible blindness.

The progression of the disease is thoroughly explored by researchers. As blindness, caused by AMD, is impossible to cure, scientists are interested in finding some solutions for slowing the progression. One of the most comprehensive studies is ‘Five-Year Progression of Unilateral Age-Related Macular Degeneration to Bilateral Involvement: The Three Continent AMD Consortium Report’, conducted by a group of professionals (Joachim et al.). The results demonstrate that during five years, “about 19–28% of unilateral any AMD cases progressed to bilateral, and 27–68% of unilateral late AMD cases progressed to bilateral in our three population-based cohorts” (Joachim et al. 1188). Apart from the age factor, the authors highlight the significant impact of genetic predisposition. In addition, the smoking habit also contributes to the rapid development of the disease. The aforementioned aspects cause the lesion of the second eye too.

Imaging Technologies Used to Understand the Disease

Imaging technologies are an integral part of establishing a diagnosis properly. Furthermore, this tool provides a comprehensive understanding of AMD pathophysiology, which helps elaborate treatment options. Imaging also allows to monitor and evaluate the current health condition, treatment response, and further progression of AMD. This method reveals abnormalities followed by the disease, such as lipofuscin, drusen deposits, subretinal fluid, RPE atrophy, and choroidal neovascularization. Applying this type of examination is highly likely to supply a patient with a precise prognosis.

Disease Treatment

As has been mentioned above, the disease’s consequences are irreversible. However, it is possible to minimize the negative effect to a large extent and slow the progression (Age-Related Macular Degeneration: What You Should Know 1). Sticking to a healthy lifestyle may be useful in the fight against the negative impacts of AMD on a patient’s health. Efrem Castillo, UnitedHealthcare chief medical officer, claims that “incorporating healthy lifestyle choices like quitting smoking; eating leafy, green vegetables and maintaining a good blood pressure and cholesterol level can help” (Age-Related Macular Degeneration: What You Should Know 1). Furthermore, completing dilated eye examinations and vision tests and monitoring the health condition appears to be beneficial for slowing the sight decline.

Despite the fact that AMD’s negative impact is unpreventable, there are some medical options of treatment, which can be successful to some extent. In the case of the wet form, such medicines as ranibizumab, bevacizumab, and aflibercept are leveraged in order to avoid splashing from new vessels. These injections should be repeated in 1 or 2 months on a regular basis, as they are helpful for preventing total blindness. Apart from that, some patients manage to recover their eyesight to the level of being able to read.

Another treatment method is photodynamic therapy, which implies an injection of a particular substance. It contributes to increasing the sensitiveness of blood vessels of the eye retina for laser irradiance. After that, new anomalous vessels are destroyed by a laser beam. In case vessels are situated near the macular, they can be removed before the process damages the eye retina. It is also worthy of note that during the wet type of AMD, surgeries are conducted rarely.

Applying metformin for recovering from AMD consequences presents a topic of multiple discussions. According to NewsRx editors, “The commonly prescribed antidiabetic drug, metformin, is associated with decreased risk of several ocular diseases, but no work has investigated the effect of metformin use on the development of AMD” (Eye Diseases and Conditions 1). A considerable number of explorations have been conducted in order to reveal the impact of this drug. One of them was held by the researchers from the Department of Ophthalmology via medical recording from patients aged over 55 and were delivered medical services at a University of Florida health clinic. The researcher’s highlight that “patients who had taken metformin had decreased odds of developing AMD, suggesting that metformin may have a therapeutic role in AMD development or progression in those who are at risk” (Eye Diseases and Conditions 1). By contrast, other medications used in the study were not as beneficial as metformin.

However, it is worthy of note that the studies are not comprehensive, and various doubts are expressed regarding the protective effect of this drug for people in the risk group. Applying metformin and its impact is not covered sufficiently, and this issue requires further exploration (Eye Diseases and Conditions 1). For this reason, the options mentioned above for slowing the progression are used, and, occasionally, the treatment appears to be surprisingly fruitful.

Risk and Genetic Factors

Although the reasons for the disease appearing are not discovered, as it has been outlined earlier, certain genetic and risk factors exist, which tend to cause the severe form of AMD. Genetic disposition to this disease can be determined by two genetic markers. ARMS2 (G205T) and CFH (C1204T) present approximately 70% of the risk of AMD development (Pham et al. 358). In addition, older patients, especially those aged over 65, are more likely to have such a diagnose as compared to the middle-aged group of people. In addition, various illnesses in the cardiovascular system, for instance, atherosclerosis, and elevated blood pressure, increase the risks of AMD. An unhealthy diet, especially whether there is a lack of omega 3 fatty acid, is among this list too.

Smoking is also associated with AMD and can have a considerable effect on disease progression. Rim et al. have conducted a study ‘A Nationwide Cohort Study of Cigarette Smoking and Risk of Neovascular Age-Related Macular Degeneration in East Asian Men’ on this topic (1367). Although it regards the Korean population, the results are appropriate for other people too. Scientist has proved that cigarette smoking presents a strong risk for AMD. Moreover, they state that “the risk of neovascular AMD among past/ current smokers was 50% higher than that among never smokers with the risk more pronounced among current than past smokers” (Rim et al. 1367). This way, the duration of sticking to this habit, as well as the daily cigarette consumption, has a significant impact on the possibility of AMD developing.

Apart from increasing the risks, the aforementioned factors also decline the progression. People, who match these characteristics, are highly likely to change from the dry to wet form rapidly. Moreover, the treatment appears to be less effective for them (Rim et al. 1370). They tend to lose their sight faster than other patients. In addition, the progression is difficult to slow for these people. However, the consequences of AMD are unpreventable, its harm can be minimized. For this reason, it is worth avoiding the risk factors to supply some chances for recovering.

Conclusion

Age-related macular degeneration leads to irreversible loss of sight, as it damaged the eye retina considerably. These days, scientists distinguish two types of disease. They are the dry and wet forms, and the latter implies the more severe stage. In order to determine the diagnosis correctly, imaging technologies are essential, as they allow to demonstrate the comprehensive picture of the disease progression and supply a patient with a prognosis. Although AMD cannot be cured in the majority of cases, some medical treatment is elaborated on slowing the development. In some cases, these options appear to be successful to some extent. However, it is crucial to avoid risk factors, which are an insufficient diet and smoking, for minimizing the negative effect of the disease.

Works Cited

“Age-Related Macular Degeneration: What You Should Know”. ProQuest, 2018, Web.

“Eye Diseases and Conditions – Age-Related Macular Degeneration; New Age-Related Macular Degeneration Data have been Reported by Researchers at Department of Ophthalmology (the Common Antidiabetic Drug Metformin Reduces Odds of Developing Age-Related Macular Degeneration).” ProQuest, Apr. 22 2019. Web.

Joachim, Nichole, et al. “Five-Year Progression of Unilateral Age-Related Macular Degeneration to Bilateral Involvement: The Three Continent AMD Consortium Report.” British Journal of Ophthalmology, vol. 101, no. 9, 2017, pp. 1185-1192.

Lee, Seong Eun, et al. “Characteristics of the Inner Retinal Layer in the Fellow Eyes of Patients with Unilateral Exudative Age-Related Macular Degeneration.” PLoS One, vol. 15, no. 9, 2020.

Pham, Thuan Quoc, et al. “Relation of Age-Related Macular Degeneration and Cognitive Impairment in an Older Population.” Gerontology, vol. 52, no. 6, 2006, pp. 353-358.

Rim, Tyler Hyungtaek, et al. “A Nationwide Cohort Study of Cigarette Smoking and Risk of Neovascular Age-Related Macular Degeneration in East Asian Men.” British Journal of Ophthalmology, vol. 101, no. 10, 2017, pp. 1367-1373.