Macular degeneration

Macular degeneration, also known as Age-related macular degeneration (AMD), is an eye disease which is the leading cause of severe, irreversible vision impairment in developed countries.1,2 This eye disease is caused by a disorder of the macula, a part of the retina at the back of the eye, that has a very high concentration of photoreceptor cells, which sends signals to the brain in order to interpret those signals as images.

Some studies have shown that 8.7% of the worldwide population has age-related macular degeneration, and the projected number of people with the disease is around 288 million in 2040.3 Furthermore, other studies have suggested substantial racial or ethnic differences in disease prevalence.3,4,5

REFERENCES

1 Flaxel, C. J., Adelman, R. A., Bailey, S. T., Fawzi, A., Lim, J. I., Vemulakonda, G. A., & Ying, G.-S. (2020). Age-related macular degeneration preferred practice pattern®. Ophthalmology127(1), P1–P65.

2 World report on vision. Geneva: World Health Organization; 2019. Licence: CC BY-NC-SA 3.0 IGO.

3 Wong, W. L., Su, X., Li, X., Cheung, C. M. G., Klein, R., Cheng, C.-Y., & Wong, T. Y. (2014). Global prevalence of age-related macular degeneration and disease burden projection for 2020 and 2040: a systematic review and meta-analysis. The Lancet. Global Health2(2), e106-16.

4Klein, R., Klein, B. E. K., Knudtson, M. D., Wong, T. Y., Cotch, M. F., Liu, K., … Jacobs, D. R., Jr. (2006). Prevalence of age-related macular degeneration in 4 racial/ethnic groups in the multi-ethnic study of atherosclerosis. Ophthalmology113(3), 373–380.

5 Klein, R., Chou, C.-F., Klein, B. E. K., Zhang, X., Meuer, S. M., & Saaddine, J. B. (2011). Prevalence of age-related macular degeneration in the US population. Archives of Ophthalmology129(1), 75–80.

Age-related macular degeneration. (2021). Nature Reviews. Disease Primers7(1), 32.

Zouache, M. A., Bennion, A., Hageman, J. L., Pappas, C., Richards, B. T., & Hageman, G. S. (2020). Macular retinal thickness differs markedly in age-related macular degeneration driven by risk polymorphisms on chromosomes 1 and 10. Scientific Reports10(1), 21093.

Tan, A. C. S., Pilgrim, M. G., Fearn, S., Bertazzo, S., Tsolaki, E., Morrell, A. P., … Curcio, C. A. (2018). Calcified nodules in retinal drusen are associated with disease progression in age-related macular degeneration. Science Translational Medicine10(466), eaat4544.

Colijn, J. M., Buitendijk, G. H. S., Prokofyeva, E., Alves, D., Cachulo, M. L., Khawaja, A. P., … Zwiener, I. (2017). Prevalence of age-related macular degeneration in Europe. Ophthalmology124(12), 1753–1763.

Bowes Rickman, C., Farsiu, S., Toth, C. A., & Klingeborn, M. (2013). Dry age-related macular degeneration: mechanisms, therapeutic targets, and imaging. Investigative Ophthalmology & Visual Science54(14), ORSF68-80.

Murdaugh, L. S., Wang, Z., Del Priore, L. V., Dillon, J., & Gaillard, E. R. (2010). Age-related accumulation of 3-nitrotyrosine and nitro-A2E in human Bruch’s membrane. Experimental Eye Research90(5), 564–571.

Jager, R. D., Mieler, W. F., & Miller, J. W. (2008). Age-related macular degeneration. The New England Journal of Medicine358(24), 2606–2617.

Birch, D. G., & Liang, F. Q. (2007). Age-related macular degeneration: a target for nanotechnology derived medicines. International Journal of Nanomedicine2(1), 65–77.

Margrain, T. H., Boulton, M., Marshall, J., & Sliney, D. H. (2004). Do blue light filters confer protection against age-related macular degeneration? Progress in Retinal and Eye Research23(5), 523–531.

Schraermeyer, U., & Heimann, K. (1999). Current understanding on the role of retinal pigment epithelium and its pigmentation. Pigment Cell Research12(4), 219–236.

Kielbassa, C., Roza, L., & Epe, B. (1997). Wavelength dependence of oxidative DNA damage induced by UV and visible light. Carcinogenesis18(4), 811–816.

Gaillard, E. R., Atherton, S. J., Eldred, G., & Dillon, J. (1995). Photophysical studies on human retinal lipofuscin. Photochemistry and Photobiology61(5), 448–453.

Rózanowska, M., Jarvis-Evans, J., Korytowski, W., Boulton, M. E., Burke, J. M., & Sarna, T. (1995). Blue light-induced reactivity of retinal age pigment: In vitro generation of oxygen-reactive species. The Journal of Biological Chemistry270(32), 18825–18830.

Weiter, J. J., Delori, F. C., Wing, G. L., & Fitch, K. A. (1986). Retinal pigment epithelial lipofuscin and melanin and choroidal melanin in human eyes. Investigative ophthalmology & visual science27(2), 145–152.

  • The World Family Macular Degeneration Center at OHSU Casey Eve
  • Wilmer Eye Institute – Jhons Hopkins Medicine
  • Harvard Medical School, Department of Ophthalmology
  • The University of British Columbia, Department of Ophthalmology and Virtual Sciences
  • Macular Research Group of Cardiff University
  • The New York Stem Cell Foundation
  • Scheie Eye Institute, University of Pennsylvania
  • BrightFocus Foundation

Despite the fact that are some studies in which the females seem to be more affected by the hypertrophic scars, probably reflecting the greater frequency of earlobe piercing among females1, in general, the researchers reach to the conclusion that men and women are similarly affected.2

REFERENCES

1 Udo-Affah, G. U., Eru, E. M., Idika, C. I., Uruakpa, K. C., & Njoku, C. C. (2014). The Age and Sex Incidence of Keloids/Hypertrophic Scars in Calabar Metropolis, Cross River State from 2001-2006. Age4(11).

2El Kinani, M., & Duteille, F. (2020). Scar epidemiology and consequences. Textbook on Scar Management (pp. 45–49). Cham: Springer International Publishing.

  • Approximately 8.7% of the total global blindness is attributed to AMD
  • The risk of getting AMD increase from 2% to 30% from the middle-aged people to the people over 75 years.
  • The Dry AMD makes up for about 90% of the total cases.
  • The Wet AMD is held responsible for only about 10% of the cases but it’s responsible for the highest number of legal blindness cases.
  • The disease is most common among older white people.
  • Risk factors:
    • Smoking
    • Dietary intake
    • Obesity
    • Hypertension
    • Sunlight exposure
    • Age
    • Gender
    • Race
    • Iris Colour
    • Genetics