title: Neurogenic vision loss: Causes and outcome. An experience from a tertiary center in Northern India.
abstract: BACKGROUND
  Vision loss can be a consequence of numerous disorders of eye and neural pathway conveying visual input to brain. A variety of conditions can affect visual pathway producing neurogenic vision loss. The presentation and course of vision loss depends on the site of involvement and underlying etiology. We conducted this unprecedented study to evaluate the characteristics and outcome of various diseases of the visual pathway.
  
  
  METHODS
  In this prospective cohort study, we evaluated 64 patients with neurogenic visual impairment. Ophthalmological causes were excluded in all of them. Their presentation, ophthalmological characteristics and investigation findings were recorded. These patients were followed up till 6 months.
  
  
  RESULTS
  Out of 69 patients evaluated, 5 were excluded as they had ophthalmological abnormalities. The remaining 64 cases (113 eyes) were enrolled. 54 cases were due to diseases of anterior visual pathway and rest 10 had cortical vision loss. The etiologic distribution is as follows: Isolated optic neuritis- 12 (19%), multiple sclerosis- 4 (6.3%), neuromyelitis optica- 5 (7.9%), tubercular meningitis- 15 (23.8%), non-arteritic ischemic optic neuropathy, ischemic optic neuropathy complicating cavernous sinus thrombosis, cryptococcal meningitis, malignant infiltration of optic nerve, Crouzon's syndrome, calvarial thickening and traumatic occipital gliosis- 1 (1.6%) case each, idiopathic intracranial hypertension, pituitary adenoma, acute disseminated encephalomyelitis, posterior reversible leukoencephalopathy- 3 (4.8%) cases each, cortical venous thrombosis 5 (7.9%), subacute scleroing panencephalitis- 4 (6.3%) cases.
  
  
  CONCLUSIONS
  The diseases of anterior visual pathway were much more common than cortical vision loss. A majority of our patients had severe impairment of vision at presentation.
authors.affiliation: Department of Neurology, King George Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Verma
authors.affiliation: Department of Neurology, King George Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Mani
authors.initials: M
authors.lastname: Gupta
authors.affiliation: Department of Neurology, King George Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Tejendra Sukdeo
authors.initials: TS
authors.lastname: Chaudhari
keywords: Cortical venous thrombosis; optic neuritis; vision loss