Which two retinal structures commonly appear white on OCT due to high reflectivity?

Which two retinal structures commonly appear white on OCT due to high reflectivity?

• A. Retinal nerve fiber layer and retinal pigment epithelium
• B. Inner nuclear layer and photoreceptor inner segments
• C. Retinal nerve fiber layer and inner plexiform layer
• D. Photoreceptor outer segments and Bruch's membrane

Answer: (A)

On OCT, brightness reflects how strongly a tissue backscatters light. The most reflective, and thus brightest, retinal layers tend to stand out as white. The retinal nerve fiber layer is highly reflective because it’s made of densely packed, tightly aligned nerve fibers that backscatter light efficiently. The retinal pigment epithelium is also very reflective due to its dense pigmentation and cellular structure, which create a strong optical boundary with Bruch’s membrane. Together, these two layers commonly appear as bright white bands on OCT. Other layers shown in the options are generally less reflective. The inner nuclear layer and inner plexiform layer have subtler backscatter, so they don’t appear as bright. The photoreceptor inner segments are moderately reflective, but not as consistently bright as the RNFL and RPE. Bruch’s membrane is a thin boundary that can be seen as a bright line in some images, but it isn’t typically as conspicuously bright as the RNFL and RPE.

On OCT, brightness reflects how strongly a tissue backscatters light. The most reflective, and thus brightest, retinal layers tend to stand out as white. The retinal nerve fiber layer is highly reflective because it’s made of densely packed, tightly aligned nerve fibers that backscatter light efficiently. The retinal pigment epithelium is also very reflective due to its dense pigmentation and cellular structure, which create a strong optical boundary with Bruch’s membrane. Together, these two layers commonly appear as bright white bands on OCT.

Other layers shown in the options are generally less reflective. The inner nuclear layer and inner plexiform layer have subtler backscatter, so they don’t appear as bright. The photoreceptor inner segments are moderately reflective, but not as consistently bright as the RNFL and RPE. Bruch’s membrane is a thin boundary that can be seen as a bright line in some images, but it isn’t typically as conspicuously bright as the RNFL and RPE.