Geographic atrophy: Etiopathogenesis and current therapies

Abstract

Geographic atrophy is characterized by severe visual deficit whose etiology and pathophysiology are yet to be elucidated. As a working hypothesis, oxidative damage could trigger a chronic inflammation in Bruch's membrane-RPE-choriocapillaris complex, mostly due to complement pathway overactivation. Some individuals with mutations in the complement system and other factors have diminished capacity in the modulation of the inflammatory response, which results in cell damage and waste accumulation. This accumulation of intracellular and extracellular waste products manifests as drusen and pigmentary changes that precede the atrophy of photoreceptors, RPE, choriocapillaris with an ischemic process with decreased choroid flow. All these processes can be detected as tomographic findings and autofluorescence signals that are useful in the evaluation of patients with atrophic AMD, which helps to establish an individualized prognosis. Anti-inflammatory, antioxidant and therapies that decrease the accumulation of toxins for the preservation of the RPE cells and photoreceptors are being investigated in order to slow down the progression of this disease.

Keywords: Atrofia geográfica; Autofluorescence imaging; Autofluorescencia; Complement system proteins; Drusas; Drusen; Estrés oxidativo; Geographic atrophy; Inflamación; Inflammation; Lipofuscin; Lipofuscina; Optical coherence tomography; Oxidative stress; Proteínas del sistema del complemento; Tomografía de coherencia óptica.