Wet AMD: treating the cause or the effect?
Image credit: http://advaitatoons.blogspot.com/2005/11/cause-and-effect-duality-illustrated.html
By Shubhankar Kulkarni on Jul 30, 2020
In Age-related Macular Degeneration (AMD), cytosolic accumulation of nuclear-DNA (nDNA) is observed in the RPE (retinal pigment epithelium) cells. The cells subsequently become senescent and secrete higher levels of VEGF and pro-inflammatory cytokines. Although the underlying cause of the development of wet AMD is not known, it is treated with antibodies against vascular endothelial growth factor (VEGF).
From what we know, secretion of VEGF seems to be an effect rather than the cause of AMD. Moreover, the role of VEGF and other pro-inflammatory cytokines is to signal the body's defense and repair mechanisms and recruit them to the sight of the damage (in this case, the RPE cells). Therefore, using antibodies against VEGF to treat AMD seems akin to treating fever by creating a cold ambient environment. Increase in body temperature during fever is an effect and not the cause. No doubt reducing the symptoms (effects) of fever (or even AMD) will have certain positive effects. However, is it the right way to go or is it the only way out we have until we find a concrete target?