title: Use of optical coherence tomography to predict visual outcome in parachiasmal meningioma.
abstract: OBJECTIVE
  The authors investigated the value of retinal nerve fiber layer (RNFL) thickness in predicting visual outcome after surgery for parachiasmal meningioma.
  
  
  METHODS
  Forty-nine eyes of 25 patients who underwent craniotomy and resection of a parachiasmal meningioma were analyzed retrospectively. Visual parameters including visual field (VF) (recorded as the mean deviation [MD]), visual acuity (VA), and RNFL thickness (via optical coherence tomography) were measured before and 1 week, 6 months, and 1 year after surgery. Postoperative visual outcome was compared among the patients with a thin or normal RNFL. A separate analysis of data pertaining to 22 eyes of 13 patients with severe VF defects (MD ≤ -10 dB) was performed to compare visual outcome for those with a thin or normal RNFL.
  
  
  RESULTS
  Of the 23 eyes that showed VF improvement, 22 (95.7%) had normal RNFL thickness. The positive predictive value of normal RNFL thickness for VF improvement was 78.6%. The VF of patients with normal RNFL thickness improved in 6 months and continued improving 1 year after surgery (MD -5.9 dB before surgery, -5.5 dB 1 week after surgery, -2.8 dB 6 months after surgery [p < 0.01], and -1.1 dB 1 year after surgery [p < 0.01]). In contrast, those with a thin preoperative RNFL showed deterioration at first and then slower, worse visual recovery after surgery (MD -18.1 dB before surgery, -22.4 dB 1 week after surgery, -21.2 dB 6 months after surgery, and -19.1 dB 1 year after surgery). VA also showed significant progress 6 months after surgery in patients with normal RNFL thickness (0.6 before surgery, 0.7 one week after surgery, 0.9 six months after surgery [p = 0.025], and 0.9 one year after surgery [p = 0.050]) compared to those with a thin RNFL (0.3 before surgery, 0.2 one week after surgery, 0.3 six months after surgery, and 0.4 one year after surgery). Preoperative differences in VF MD and VA were noted between the 2 groups (p < 0.01). Even patients with severe VF defects and normal RNFL thickness improved by 11.1 dB by 1 year after surgery compared with patients with a thin RNFL (-0.01 dB) (p < 0.01). Patients with normal RNFL thickness also did better in VA improvement (from 0.7 to 1.1) than those with a thin RNFL (from 0.2 to 0.3), but these results were not statistically significant.
  
  
  CONCLUSIONS
  RNFL thickness measured by optical coherence tomography has significant value as a prognostic factor of postoperative visual recovery for parachiasmal meningioma. Patients with normal RNFL thickness before surgery are more likely to have visual improvement after surgery than patients with a thin RNFL.
authors.affiliation: Departments of 1 Neurosurgery and.|Brain Tumor Center, and.
authors.forename: Hun Ho
authors.initials: HH
authors.lastname: Park
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Min Chul
authors.initials: MC
authors.lastname: Oh
authors.affiliation: Departments of 1 Neurosurgery and.|Brain Tumor Center, and.|Brain Research Institute, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Eui Hyun
authors.initials: EH
authors.lastname: Kim
authors.affiliation: Ophthalmology.
authors.forename: Chan Yun
authors.initials: CY
authors.lastname: Kim
authors.affiliation: Departments of 1 Neurosurgery and.|Brain Tumor Center, and.|Brain Research Institute, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Sun Ho
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Departments of 1 Neurosurgery and.|Brain Tumor Center, and.|Brain Research Institute, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Kyu-Sung
authors.initials: KS
authors.lastname: Lee
authors.affiliation: Departments of 1 Neurosurgery and.|Brain Tumor Center, and.|Brain Research Institute, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Jong Hee
authors.initials: JH
authors.lastname: Chang
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000473:pathology / Q000601:surgery*; D008579:Meningioma / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009897:Optic Chiasm / Q000473:pathology*; D011237:Predictive Value of Tests; D020127:Recovery of Function; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D014786:Vision Disorders / Q000209:etiology / Q000473:pathology / Q000601:surgery*
keywords: MD = mean deviation; OCT = optical coherence tomography; RGC = retinal ganglion cell; RNFL = retinal nerve fiber layer; SAP = standard automated perimetry; TSA = transsphenoidal approach; VA = visual acuity; VF = visual field; diagnostic and operative techniques; optical coherence tomography; parachiasmal meningioma; retinal nerve fiber layer; visual acuity; visual field