Understanding Geographic Atrophy (GA)

Sample OCT scan showing choroidal hypertransmission

Know these symptoms of GA

Check to see if your patients are experiencing any of the signs of GA below. Patients with GA may experience one or more of these symptoms.^1,2

Straight lines that appear crooked

Hazy or blurred vision

Blurry spot in the center of vision

Dull or washed-out colors

Difficulty seeing in low light

Missing spots in vision

Risk factors for the development of GA

Genetics

Family history³
(genetic predisposition)

Physiology

Age³

Obesity³

Certain dyslipidemias³

Cardiovascular disease/hypertension³

Lifestyle/Environment

History of smoking³
Diet³

Clinical Findings from Imaging

GA in fellow eye⁴
Increased drusen volume⁵

From age 50,
the prevalence of GA
quadruples every 10 years⁶

GA and AMD

GA is the advanced form of dry age-related macular degeneration (AMD).⁴

Click on the tabs below to learn more.

Few medium-sized drusen

Medium-sized drusen >63 µm and ≤125 µm
No pigmentary abnormalities

Drusen grow larger with disease progression

Large drusen >125 µm and/or pigmentary abnormalities
Can lead to GA, nAMD, or both GA and nAMD

Hypertransmission seen in GA

GA^4,9-15

Atrophy of photoreceptors and the loss of RPE can lead to increased reflectivity below Bruch’s membrane and resulting hypertransmission
Even if visual acuity or BCVA is relatively unchanged, functional vision continues to decline as lesions progress
Patients with GA can also naturally develop nAMD and vice versa. Up to 29% of patients with GA develop nAMD in about 2 years (N=12,309)*

The overall prevalence of GA and nAMD is similar, with nearly 1 million of each diagnosed in the US^17,18§

*Respective analysis of the Intelligent Research in Sight (IRIS) Registry database (n=3607/12,309) in patients with GA in the study eye and nAMD in the fellow eye.¹⁵

†Retrospective cohort analysis (N=91) to assess growth of GA in patients with nAMD treated with anti-VEGF therapy.¹⁶

‡GA in patients with prior wet AMD might have some different disease characteristics.

§Prevalence of GA and nAMD in the US are ~973,000 and ~1.2 million respectively.¹⁸

BCVA=best-corrected visual acuity; nAMD=neovascular age-related macular degeneration; RPE=retinal pigment epithelium; VEGF=vascular endothelial growth factor.

Complement overactivation is strongly associated with GA progression^19,20

c3 cascade

3 cascade

When C3, the central protein in the complement cascade, is overactivated, negative effects are unleashed downstream. Increased levels of complement activity has been found in GA lesions and surrounding areas including photoreceptors.^22,24

See how GA may impact your patients

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Int J Mol Sci. 2021;22(3):1296. doi:10.3390/ijms22031296. 10. Chakravarthy U, Bailey CC, Scanlon PH, et al. Progression from early/intermediate to advanced forms of age-related macular degeneration in a large UK cohort: rates and risk factors. Ophthalmol Retina. 2020;4(7):662-672. doi:10.1016/j.oret.2020.01.012. 11. Boyer DS, Schmidt-Erfurth U, van Lookeren Campagne M, Henry EC, Brittain C. The pathophysiology of geographic atrophy secondary to age-related macular degeneration and the complement pathway as a therapeutic target. Retina. 2017;37(5):819-835. doi:10.1097/iae.0000000000001392. 12. Sunness JS, Margalit E, Srikumaran D, et al. The long-term natural history of geographic atrophy from age-related macular degeneration: enlargement of atrophy and implications for interventional clinical trials. Ophthalmology. 2007;114(2):271-277. doi:10.1016/j.ophtha.2006.09.016. 13. Kimel M, Leidy NK, Tschosik E, et al. 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