title: Visual field defect after pars plana vitrectomy.
abstract: OBJECTIVE
  This study aimed to report the occurrence of visual field defects after pars plana vitrectomy (PPV) for the treatment of each of the following conditions: macular hole (MH), subretinal neovascular membrane (SRNVM), and epiretinal membrane proliferation (EMP). This study also aimed to speculate on the pathogenic mechanisms for the observed field defects.
  
  
  METHODS
  Noncomparative case series.
  
  
  METHODS
  The study included 48 subjects (50 eyes). Twenty-one of the 50 eyes had stage III MH, 13 eyes had SRNVM, and 16 eyes had EMP.
  
  
  METHODS
  Goldmann kinetic perimetry was performed postoperatively.
  
  
  METHODS
  Visual field defects.
  
  
  RESULTS
  Nine (18%) of the 50 eyes had visual field defects. Four (19%) of the 21 eyes with MH and 5 (38%) of the 13 eyes with SRNVM had visual field defects. Of the 16 patients who had epiretinal membrane peeling, none had a visual field defect. An air-fluid exchange had been performed in all patients found to have a postvitrectomy field defect. The difference in rate of visual field defects in eyes that had air-fluid exchange (EMP group) was statistically significant (P < 0.05, chi-square). No significant correlation was found between visual field defect and preoperative intraocular pressure, postoperative intraocular pressure, patient's age, and iatrogenic detachment of the vitreous cortex. The field defects identified were altitudinal (2 eyes), baring of the blind spot (1 eye), inferotemporal (3 eyes), inferonasal (2 eyes), and superonasal (1 eye).
  
  
  CONCLUSIONS
  Central and peripheral visual field defects may occur after PPV for the treatment of MHs or SRNVMs. Air-fluid exchange procedure was the common denominator in all of the patients found to have visual field deficit. The etiology is likely to be trauma to the optic nerve region during the air-fluid exchange procedure.
authors.affiliation: Department of Ophthalmology, Tianjin Medical University Hospital, Peoples Republic of China.
authors.forename: H
authors.initials: H
authors.lastname: Yan
authors.forename: L
authors.initials: L
authors.lastname: Dhurjon
authors.forename: D R
authors.initials: DR
authors.lastname: Chow
authors.forename: D
authors.initials: D
authors.lastname: Williams
authors.forename: J C
authors.initials: JC
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019773:Epiretinal Membrane / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015861:Retinal Neovascularization / Q000601:surgery; D012167:Retinal Perforations / Q000601:surgery; D014786:Vision Disorders / Q000209:etiology*; D058609:Visual Field Tests; D014794:Visual Fields; D014821:Vitrectomy / Q000009:adverse effects*