title: Optic nerve sheath decompression for visual loss in intracranial hypertension: report from a tertiary care center in South India.
abstract: OBJECTIVE
  Severe visual loss is the only serious complication of intracranial hypertension secondary to idiopathic intracranial hypertension (IIH) and some cases of cerebral venous thrombosis (CVT). Optic nerve sheath decompression (ONSD) has been shown to improve or stabilize visual function in patients with IIH, while its role in CVT is yet to be established. We report our experience with optic nerve sheath decompression for visual loss in IIH and CVT.
  
  
  METHODS
  In this prospective noncomparative, interventional study, 41 eyes of 21 patients with IIH and CVT and visual loss underwent ONSD. The main outcome measures included best-corrected visual acuity (BCVA), visual fields, pupillary light reflex, optic nerve sheath diameter on B-scan and resolution of papilledema which were evaluated preoperatively and at follow-up at four days, two weeks, one month, three months and final follow-up. In 7/41 eyes with absent light perception preoperatively, the functional outcome was analyzed separately.
  
  
  RESULTS
  Following ONSD BCVA and visual fields stabilized or improved in 32/34 (94%) eyes. Statistically significant improvement in BCVA, visual fields and pupillary light reflex occurred over the three month follow-up period. Surgical success was indicated by reduction in optic nerve diameter and papilledema resolution occurred in all patients. The outcome in the IIH and CVT groups was comparable. Four eyes with absent light perception showed marginal improvement in visual acuity. Four eyes had transient benign complications.
  
  
  CONCLUSIONS
  Optic nerve sheath decompression is an effective and safe procedure to improve or stabilize vision in patients with visual loss caused by IIH and CVT.
authors.affiliation: Department of Ophthalmology, St Johns Medical College Hospital, Bangalore - 560 034, India. suneetha_lobo@rediffmail.com
authors.forename: Suneetha
authors.initials: S
authors.lastname: Nithyanandam
authors.forename: George J
authors.initials: GJ
authors.lastname: Manayath
authors.forename: Ravindra R
authors.initials: RR
authors.lastname: Battu
mesh_terms: D000293:Adolescent; D000328:Adult; D001766:Blindness / Q000209:etiology / Q000534:rehabilitation*; D019299:Decompression, Surgical / Q000379:methods*; D005260:Female; D006801:Humans; D007427:Intracranial Pressure; D008297:Male; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures; D009900:Optic Nerve / Q000601:surgery*; D011446:Prospective Studies; D011559:Pseudotumor Cerebri / Q000150:complications / Q000601:surgery*; D012851:Sinus Thrombosis, Intracranial / Q000150:complications / Q000601:surgery; D014792:Visual Acuity; D014794:Visual Fields; D055815:Young Adult