CAMKK2 and age-related macular degeneration: The cytoprotective mechanism by which artemisinin enhances the antioxidant capacity of RPE cells via the CaMKK2/AMPK/Nrf2 signalling pathway in the context of amiodarone-induced retinal injury may also provide clues for treating AMD and other retinal degenerative diseases characterized by the loss of photoreceptors or RPE cells.