Optic nerve: a concise review of the anatomy, pathophysiology and principal acquired disorders

Abstract

The Authors review the acquired diseases of the optic nerve (o.n.) through a selection of a few main nosological categories elaborated according to recent literature and neuro-imaging developments. The proposed selection does not coincide with a classification as it includes different topics, some listed according to their aetiology, others on the clinical presentation. However, from a practical point of view, a simplified nosology should help in dealing with the complex variety of o.n. diseases and in tackling the difficulties of their differential diagnosis.

The Role of Axonal Transport in Glaucoma

“…Neurons have a particularly polarized cell morphology that makes transport even more important, with several projections, including dendrites and a long axon, which extend far from the cell body, where most cell machinery is located [ 14 , 63 ]. In particular, the axons of RGCs span a considerable length running from the retina to the superior colliculus and the lateral geniculate nucleus at the posterior part of the brain [ 64 , 65 ]. Axonal transport is an ATP-dependent process, during which cytoskeleton-associated motor proteins actively carry different types of cargos along microtubules in the axons [ 15 ].…”

The Role of Axonal Transport in Glaucoma

“…Neurons have a particularly polarized cell morphology that makes transport even more important, with several projections, including dendrites and a long axon, which extend far from the cell body, where most cell machinery is located [ 14 , 63 ]. In particular, the axons of RGCs span a considerable length running from the retina to the superior colliculus and the lateral geniculate nucleus at the posterior part of the brain [ 64 , 65 ]. Axonal transport is an ATP-dependent process, during which cytoskeleton-associated motor proteins actively carry different types of cargos along microtubules in the axons [ 15 ].…”

Associations between retinal nerve fiber layer abnormalities and optic nerve examination

“…Multiple sclerosis (MS) is the primary cause of nontraumatic disability among young adults, and visual dysfunction is a major cause of disability in MS. 1-3 Examination of the peripapillary retinal nerve fiber layer (RNFL) provides a unique opportunity to directly visualize unmyelinated CNS axons and detect evidence of CNS pathology. [4][5][6] Traditionally, physicians have used the detection of optic disc pallor and afferent pupillary defects (APD) during clinical examination as signs of optic neuropathy. 7,8 Optical coherence tomography (OCT) is a high-resolution, noninvasive imaging technique that uses near infrared light to produce images used to generate quantitative measurements of the RNFL.…”

“…[4][5][6] Traditionally, physicians have used the detection of optic disc pallor and afferent pupillary defects (APD) during clinical examination as signs of optic neuropathy. 7,8 Optical coherence tomography (OCT) is a high-resolution, noninvasive imaging technique that uses near infrared light to produce images used to generate quantitative measurements of the RNFL.…”

The Role of Axonal Transport in Glaucoma

“…Neurons have a particularly polarized cell morphology that makes transport even more important, with several projections, including dendrites and a long axon, which extend far from the cell body, where most cell machinery is located [ 14 , 63 ]. In particular, the axons of RGCs span a considerable length running from the retina to the superior colliculus and the lateral geniculate nucleus at the posterior part of the brain [ 64 , 65 ]. Axonal transport is an ATP-dependent process, during which cytoskeleton-associated motor proteins actively carry different types of cargos along microtubules in the axons [ 15 ].…”

Associations between retinal nerve fiber layer abnormalities and optic nerve examination

“…Multiple sclerosis (MS) is the primary cause of nontraumatic disability among young adults, and visual dysfunction is a major cause of disability in MS. 1-3 Examination of the peripapillary retinal nerve fiber layer (RNFL) provides a unique opportunity to directly visualize unmyelinated CNS axons and detect evidence of CNS pathology. [4][5][6] Traditionally, physicians have used the detection of optic disc pallor and afferent pupillary defects (APD) during clinical examination as signs of optic neuropathy. 7,8 Optical coherence tomography (OCT) is a high-resolution, noninvasive imaging technique that uses near infrared light to produce images used to generate quantitative measurements of the RNFL.…”

“…[4][5][6] Traditionally, physicians have used the detection of optic disc pallor and afferent pupillary defects (APD) during clinical examination as signs of optic neuropathy. 7,8 Optical coherence tomography (OCT) is a high-resolution, noninvasive imaging technique that uses near infrared light to produce images used to generate quantitative measurements of the RNFL.…”

The Role of Axonal Transport in Glaucoma

“…Neurons have a particularly polarized cell morphology that makes transport even more important, with several projections, including dendrites and a long axon, which extend far from the cell body, where most cell machinery is located [ 14 , 63 ]. In particular, the axons of RGCs span a considerable length running from the retina to the superior colliculus and the lateral geniculate nucleus at the posterior part of the brain [ 64 , 65 ]. Axonal transport is an ATP-dependent process, during which cytoskeleton-associated motor proteins actively carry different types of cargos along microtubules in the axons [ 15 ].…”

Associations between retinal nerve fiber layer abnormalities and optic nerve examination

“…Multiple sclerosis (MS) is the primary cause of nontraumatic disability among young adults, and visual dysfunction is a major cause of disability in MS. 1-3 Examination of the peripapillary retinal nerve fiber layer (RNFL) provides a unique opportunity to directly visualize unmyelinated CNS axons and detect evidence of CNS pathology. [4][5][6] Traditionally, physicians have used the detection of optic disc pallor and afferent pupillary defects (APD) during clinical examination as signs of optic neuropathy. 7,8 Optical coherence tomography (OCT) is a high-resolution, noninvasive imaging technique that uses near infrared light to produce images used to generate quantitative measurements of the RNFL.…”

“…[4][5][6] Traditionally, physicians have used the detection of optic disc pallor and afferent pupillary defects (APD) during clinical examination as signs of optic neuropathy. 7,8 Optical coherence tomography (OCT) is a high-resolution, noninvasive imaging technique that uses near infrared light to produce images used to generate quantitative measurements of the RNFL.…”