Macular degeneration

What is macular degeneration?

Macular degeneration is the result of damage or loss of cells in the macula, a small area at the centre of the retina of the eye. The most common form is age-related macular degeneration (AMD), an eye condition that slowly worsens over time, usually affecting people aged 55 or over¹. Other than older age, risk factors for age-related macular degeneration include obesity, high blood pressure, smoking, being female, and lighter skin and eye colour^2,3.

What are the symptoms of macular degeneration?

Age-related macular degeneration symptoms include progressive worsening of central vision over time. There are two forms of AMD; dry macular degeneration that is much more common (approximately 90% of cases), and wet macular degeneration⁴. In the case of dry macular degeneration, central vision may become dim or blurry, with blind spots and loss of central vision occurring at an advanced stage. Wet macular degeneration is caused by excessive leaking from blood vessels near the macula, with symptoms that include seeing straight lines as wavy or distorted, and progressive central vision loss³.

How is macular degeneration diagnosed?

Diagnosis of macular degeneration is done through a routine eye examination. The appearance of yellow spots underneath the retina (drusen) is a key sign of macular degeneration². Vision tests such as the Amsler grid may be used to assess central vision and a person’s ability to see straight lines³. Procedures such as angiography or an optical coherence tomogram (OCT) can be used to confirm a macular degeneration diagnosis.

How is macular degeneration treated?

Treatments for macular degeneration are limited. Management options such as lifestyle changes, such as eating healthily and not smoking, may help to delay progression of early AMD. Wet macular degeneration can be treated with anti-angiogenesis drugs (anti-VEGF drugs) that help to prevent blood vessel growth and leakage^3,5. Photodynamic therapy (PDT) or laser therapy may also be used to remove problematic blood vessels. Emerging treatments for macular degeneration that are under investigation include retinal gene therapy for wet AMD, and retinal stem cell therapy for dry AMD⁵.

References

1. What is macular degeneration? American Macular Degeneration Foundation. https://www.macular.org/what-macular-degeneration. Accessed 09 March 2021.
2. Heesterbeek TJ, Lorés-Motta L, Hoyng CB, Lechanteur YTE, den Hollander AI. Risk factors for progression of age-related macular degeneration. Ophthalmic Physiol Opt. 2020;40(2):140–170.
3. Pugazhendhi A, Hubbell M, Jairam P, Ambati B. Neovascular Macular Degeneration: A Review of Etiology, Risk Factors, and Recent Advances in Research and Therapy. Int J Mol Sci. 2021;22(3):1170.
4. Dry vs wet age-related macular degeneration. American Macular Degeneration Foundation. https://www.macular.org/dry-vs-wet-macular-degeneration. Accessed 09 March 2021. 
5. Ammar MJ, Hsu J, Chiang A, Ho AC, Regillo CD. Age-related macular degeneration therapy: a review. Curr Opin Ophthalmol. 2020;31(3):215–221.