How does optical coherence tomography reveal nerve fiber layer thinning in glaucoma?

How does optical coherence tomography reveal nerve fiber layer thinning in glaucoma?

• A. Optical coherence tomography (OCT) shows peripapillary RNFL thinning and glaucomatous notching of the neuroretinal rim
• B. MRI shows optic nerve enhancement
• C. Visual fields show central scotoma
• D. Fundus shows pallor of the disc

Answer: (A)

Optical coherence tomography images the retina with light to measure the thickness of each layer, especially the retinal nerve fiber layer around the optic nerve head. In glaucoma, retinal ganglion cell axons are progressively lost, so the RNFL becomes thinner. OCT translates this thinning into quantitative RNFL thickness values and color-coded maps. A characteristic result is thinning in the peripapillary RNFL with focal, wedge-shaped loss known as glaucomatous notching of the neuroretinal rim. This combination shows up on OCT as reduced RNFL thickness and localized rim thinning, capturing the structural damage glaucoma causes. Other options describe imaging or functional findings from different tests and do not reflect how OCT specifically reveals RNFL thinning.

Optical coherence tomography images the retina with light to measure the thickness of each layer, especially the retinal nerve fiber layer around the optic nerve head. In glaucoma, retinal ganglion cell axons are progressively lost, so the RNFL becomes thinner. OCT translates this thinning into quantitative RNFL thickness values and color-coded maps. A characteristic result is thinning in the peripapillary RNFL with focal, wedge-shaped loss known as glaucomatous notching of the neuroretinal rim. This combination shows up on OCT as reduced RNFL thickness and localized rim thinning, capturing the structural damage glaucoma causes. Other options describe imaging or functional findings from different tests and do not reflect how OCT specifically reveals RNFL thinning.