title: Optic Nerve Sheath Fenestration: Current Preferences in Surgical Approach and Biopsy.
abstract: OBJECTIVE
  Optic nerve sheath fenestration (ONSF) has evolved since its inception in 1872. Surgical approaches include a lateral orbitotomy, a medial orbitotomy, or a superomedial lid crease. The actual fenestration can be done with slits or a window excision with biopsy. Each variation has its advantages and disadvantages. We describe the current preferences in surgical approach and biopsy for ONSF and examine the value of biopsy in patients who have undergone ONSF.
  
  
  METHODS
  Eight-question survey and retrospective, noncomparative case review.
  
  
  METHODS
  All American Society of Ophthalmic Plastic and Reconstructive Surgeons (ASOPRS) members are invited to participate in a survey and ONSFs from 1998 to 2013 at the University of Iowa Hospital and Clinics.
  
  
  METHODS
  Data from the survey was analyzed and patient records were reviewed.
  
  
  METHODS
  Preferred surgical approach, type of fenestration, and biopsy results.
  
  
  RESULTS
  Sixty-four percent of responding ASOPRS members (150/236) have not performed an ONSF in the last year. One third of that group has performed an ONSF in the last 5 years. Fifty-nine percent perform a medial; 10%, a lateral and 31%, a superomedial approach. Seventy-three percent perform a window fenestration, and about half of those surgeons send the specimen for pathologic evaluation. Anecdotally, some biopsies from surgeons who were surveyed have revealed new diagnoses. In a chart review of 90 cases of ONSF, no biopsy gave an unexpected result.
  
  
  CONCLUSIONS
  The medial approach for ONSF is most common in our respondents; however, the superomedial lid crease incision is gaining popularity for its efficiency and elegance. Three quarters of surgeons remove a window and a quarter fenestrate with slits. Optic nerve sheath biopsy has limited diagnostic value. In the absence of any evidence to suggest a diagnosis other than idiopathic intracranial hypertension, the usefulness of biopsy during fenestration is low.
authors.affiliation: *Department of Ophthalmology and Visual Sciences; †Department of Pathology; and ‡Department of Otolaryngology-Head and Neck Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, U.S.A.
authors.forename: Rachel K
authors.initials: RK
authors.lastname: Sobel
authors.forename: Nasreen A
authors.initials: NA
authors.lastname: Syed
authors.forename: Keith D
authors.initials: KD
authors.lastname: Carter
authors.forename: Richard C
authors.initials: RC
authors.lastname: Allen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D019299:Decompression, Surgical / Q000379:methods*; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures; D009885:Ophthalmology / Q000706:statistics & numerical data*; D009901:Optic Nerve Diseases / Q000175:diagnosis / Q000601:surgery*; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D011559:Pseudotumor Cerebri / Q000175:diagnosis / Q000601:surgery*; D012189:Retrospective Studies; D011795:Surveys and Questionnaires