External Limiting Membrane (ELM) is described as a barrier between which structures?

External Limiting Membrane (ELM) is described as a barrier between which structures?

• A. A barrier between the inner and outer segments of the photoreceptors
• B. The barrier between the retina and choroid
• C. The synaptic interface between photoreceptors and bipolar cells
• D. A barrier between the inner retina and vitreous

Answer: (A)

The External Limiting Membrane is a boundary formed by junctional complexes between Müller glial cells and photoreceptor inner segments, creating a barrier that separates the photoreceptor inner segments from the outer segments. This helps maintain the distinct environments and alignment of the photoreceptor compartments, contributing to retinal structural integrity. On OCT it shows up as a thin, continuous hyperreflective line just outside the outer nuclear layer, marking the limit between inner and outer photoreceptor regions. It is not the barrier between retina and choroid, nor the synaptic interface between photoreceptors and bipolar cells, nor the barrier between the inner retina and vitreous.

The External Limiting Membrane is a boundary formed by junctional complexes between Müller glial cells and photoreceptor inner segments, creating a barrier that separates the photoreceptor inner segments from the outer segments. This helps maintain the distinct environments and alignment of the photoreceptor compartments, contributing to retinal structural integrity. On OCT it shows up as a thin, continuous hyperreflective line just outside the outer nuclear layer, marking the limit between inner and outer photoreceptor regions. It is not the barrier between retina and choroid, nor the synaptic interface between photoreceptors and bipolar cells, nor the barrier between the inner retina and vitreous.