Optic neuropathy

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Luke Rusowicz-Orazem, B.S.

Overview

Optic neuropathy refers to damage to the optic nerve due to any cause.

Pathophysiology

The primary change occurring in optic neuropathy is nerve cell damage. The optic nerve comprises axons that emerge from the retina of the eye and carry visual information to the primary visual nuclei, most of which is relayed to the occipital cortex of the brain to be processed into vision. Neurons from retina leave the eye at the optic disc, and go to the visual cortex via the optic nervce, optic chiasm, optic tract and optic radiations. Damage and death of these neurons leads to characteristic features of optic neuropathy.

Causes

Common Causes

Causes by Organ System

Cardiovascular	Acute hypotension , Allergic vasculitis, Arteriosclerosis, Buerger disease, Carotid occlusive disease, Cavernous hemangiomas, Central retinal artery occlusion, Central retinal vein occlusion, Cholesterol granuloma, Hypertension, Optic nerve vascular lesions, Polyarteritis nodosa, Postviral vasculitis, Takayasu disease, Temporal arteritis, Vascular occlusions of the optic nerve, Vasculitis
Chemical/Poisoning	Bee stings, Lead poisoning, Methanol, Methyl alcohol consumption
Dental	No underlying causes
Dermatologic	Dermoid cysts, Orbital cellulitis
Drug Side Effect	Ak-chlor, Cetina, Chloramphenicol, Clorafen, Diochloram, Ethambutol, Isoniazid, Oprelvekin, Paraxin, Pentamycetin, Quemicetina, Quinine, Sopamycetin, Streptomycin, Thallium
Ear Nose Throat	Mucoceles, Sinusitis
Endocrine	Glucose-6-phosphate dehydrogenase deficiency , Hyperthyroidism, Thyroid opthalmopathy
Environmental	No underlying causes
Gastroenterologic	No underlying causes
Genetic	Wagener syndrome
Hematologic	Buerger disease, Cavernous hemangiomas, Cranial blood suppy disorders , Diabetes mellitus, Giant cell arteritis, Glucose-6-phosphate dehydrogenase deficiency , Pernicious anaemia, Polycythemia vera, Sickle cell disease
Iatrogenic	Postimmunization, Radiation necrosis
Infectious Disease	Borrelia burgdorferi, Brucellosis, Cat scratch fever, Conjunctival orbital cysts, Cytomegalovirus, Dermoid cysts, Herpes zoster, Hiv-1 disease, Infectious mononucleosis, Influenza, Lyme disease, Measles, Meningitis, Mumps, Onchocerciasis, Orbital abscess, Orbital cellulitis, Posterior uveitis, Postviral vasculitis, River blindness , Sinusitis, Syphillis, Treponema pallidum, Tuberculosis, Varicella, Viral encephalitis
Musculoskeletal/Orthopedic	Encephalomyelitis, Neuromyelitis optica
Neurologic	Acute disseminated encephalomyelitis , Anterior ischemic optic neuropathy, Benign multiple sclerosis , Cranial blood suppy disorders , Demyelinating disorders, Diffuse sclerosis of schilder, Encephalomyelitis, Guillain-barre syndrome, Leber’s optic neuropathy, Low tension migrane, Meningioma, Meningitis, Migraine, Multiple sclerosis, Nerve damage, Neurofibromatosis, Neuromyelitis optica, Optic nerve glioma, Optic nerve tumors, Orbital abscess, Schilder’s disease, Sudanophilic cerebral sclerosis, Viral encephalitis
Nutritional/Metabolic	Diabetes mellitus
Obstetric/Gynecologic	No underlying causes
Oncologic	Meningioma, Metastases, Optic nerve tumors, Polycythemia vera, Primary malignancies, Solid orbital tumors
Ophthalmologic	Anterior ischemic optic neuropathy, Central retinal artery occlusion, Central retinal vein occlusion, Chloroptic, Conjunctival orbital cysts, Intraocular hypertension, Leber’s optic neuropathy, Low-tension glaucoma, Ophthochlor, Optic nerve glioma, Optic nerve vascular lesions, Papillitis, Postcataract, Posterior uveitis, Thyroid opthalmopathy, Vascular occlusions of the optic nerve, Wagener syndrome
Overdose/Toxicity	Tobacco
Psychiatric	No underlying causes
Pulmonary	Churg-strauss syndrome, Sarcoidosis
Renal/Electrolyte	No underlying causes
Rheumatology/Immunology/Allergy	Churg-strauss syndrome, Diffuse sclerosis of schilder, Neurofibromatosis, Sarcoidosis, Systemic lupus erythematosus, Takayasu disease
Sexual	Hiv-1 disease, Syphillis, Treponema pallidum
Trauma	Bee stings, Head trauma
Urologic	No underlying causes
Miscellaneous	No underlying causes

Causes in Alphabetical Order

Signs and symptoms

Major symptoms are sudden or gradual loss of vision (partial or complete). There may or may not be pain on movement of the affected eye. Patients may lose some of their color vision in the affected eye, with colours appearing subtly washed out compared to the other eye.

On medical examination the head of the optic nerve can easily be visualised by an ophthalmoscope. A pale disc is characteristic of optic neuropathy. Primary and secondary optic neuropathy may have different morphological presentation. The nerve head in optic neuritis may be swollen in some patients. In many cases, only one eye is affected and patients may not be aware of the loss of color vision until the doctor asks them to close or cover the healthy eye.

Differential Diagnosis

Acute angle closure glaucoma
Anterior ischemic optic neuropathy
Branch retinal artery occlusion
Central retinal artery occlusion
Compressive optic neuropathy
Meningioma
Multiple Sclerosis
Optic Neuritis
Sarcoidosis
Sudden visual loss
Syphillis
Thyroid opthalmopathy ^[1] ^[2]

References

↑ Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:77 ISBN 1591032016
↑ Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:68 ISBN 140510368X