The external limiting membrane (ELM) and ellipsoid zone (EZ) can be observed exquisitely by SD-OCT. In diabetic macular edema (DME), dysfunction of mitochondria, represented by the EZ in the foveal photoreceptors results in reduced visual acuity (VA). An increase in VEGF was found to correlate with increased severity of DR, increased central subfield thickness (CST), and sequential disruption of ELM and EZ. The mechanism of ELM and EZ restoration after anti-VEGF therapy in DME has been discovered. The ELM restores first followed by EZ restoration. Thus, authors have discovered and established ELM as a novel retinal structural barrier.
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