Neuro-ophthalmic disease and optical coherence tomography: glaucoma look-alikes

Abstract

Purpose of review: The use of optical coherence tomography (OCT)-measured retinal nerve fiber layer (RNFL) thickness in neuro-ophthalmic disease has grown since its first use in glaucoma and retinal diseases. OCT-measured RNFL in nonglaucomatous optic neuropathies shows thinning, which may mimic those seen in glaucoma. This article aims to provide insight regarding the use of OCT in nonglaucomatous optic neuropathies and sheds light on common patterns of RNFL loss in different nonglaucomatous optic neuropathies.

Recent findings: RNFL thinning is most likely to occur in the temporal peripapillary quadrant than in other quadrants in nonglaucomatous optic neuropathies. The pattern of RNFL thinning in ischemic optic neuropathy and optic nerve head drusen is more likely to mimic the pattern found in glaucoma due to the superior and inferior quadrant predilection. OCT-measured RNFL thickness in Alzheimer's disease reveals thinning superiorly and inferiorly, whereas superior and temporal thinning is seen in Parkinson's disease. The thinning observed in neurodegenerative diseases is believed to be multifactorial including causes such as axonal degeneration and retrograde degeneration. However, more studies are needed to further study these changes.

Summary: OCT is a valuable tool in evaluating the peripapillary RNFL in both glaucomatous and nonglaucomatous optic neuropathies. This technology may be used for both research and clinical purposes to assess disease progression in optic neuropathies and diseases that affect the central nervous system. OCT-measured RNFL thickness remains complimentary to the clinical examination skills in the evaluation of nonglaucomatous optic neuropathies.