title: Changes of parafoveal retinal nerve fiber layer thickness analyzed by spectral-domain optical coherence tomography after pars plana vitrectomy.
abstract: OBJECTIVE
  To use spectral-domain optical coherence tomography to evaluate the postoperative retinal nerve fiber layer (RNFL) thickness changes in eyes undergoing vitrectomy.
  
  
  METHODS
  This is a retrospective study of 44 patients (44 eyes) who underwent monocular vitrectomy for an epiretinal membrane (19 eyes), macular hole (12 eyes), or vitreous hemorrhage (13 eyes). Quantitative analysis of the peripapillary RNFL by spectral-domain optical coherence tomography was performed before surgery and for 6 months postoperatively on both eyes.
  
  
  RESULTS
  Mean patient age was 62.72 ± 9.11 years. Mean preoperative RNFL thickness did not differ significantly between vitrectomized eyes (88.33 ± 13.23 μm) and nonvitrectomized fellow eyes (87.49 ± 13.18 μm; P > 0.05). In vitrectomized eyes, the preoperative mean RNFL thickness in the superior quadrant was significantly different from that at 6 months after surgery (P = 0.02). Vitrectomized eyes with a macular hole showed significant changes in the mean RNFL thickness in the inferior quadrant (P = 0.04).
  
  
  CONCLUSIONS
  Retinal nerve fiber layer thickness was reduced in some of the quadrants of the vitrectomized eye during the 6-month postoperative follow-up period. Spectral-domain optical coherence tomography can be clinically useful for detection of localized RNFL defects in patients who underwent vitrectomy. Future prospective studies with more patients and longer follow-up duration are required.
authors.affiliation: Department of Ophthalmology, Kyung Hee University Hospital, Kyung Hee University, Seoul, Korea.
authors.forename: Kook Young
authors.initials: KY
authors.lastname: Kim
authors.forename: Seung-Young
authors.initials: SY
authors.lastname: Yu
authors.forename: Moo Sang
authors.initials: MS
authors.lastname: Kim
authors.forename: Eung Suk
authors.initials: ES
authors.lastname: Kim
authors.forename: Hyung Woo
authors.initials: HW
authors.lastname: Kwak
mesh_terms: D000328:Adult; D000368:Aged; D002387:Cataract Extraction; D019773:Epiretinal Membrane / Q000601:surgery*; D005260:Female; D005584:Fovea Centralis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009929:Organ Size; D011184:Postoperative Period; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence; D014821:Vitrectomy