title: [Detection of the changes of retinal nerve fiber layer thickness by GDx-VCC laser scanning polarimetry in primary open angle glaucoma patients].
abstract: OBJECTIVE
  To evaluate the changes of visual field and retinal nerve fiber layer (RNFL) thickness during 24 months follow up in primary open-angle glaucoma (POAG) patients.
  
  
  METHODS
  In this retrospective case series study, visual field and RNFL were detected by using GDx-VCC system and Octopus perimeter in 60 patients with POAG in early stage (60 eyes), 32 in moderate stage (32 eyes) and 30 in advanced stage (30 eyes). The parameters of the RNFL thickness and mean defect (MD) of the visual fields were recorded and analyzed by repeated measures analysis of variance among the same group and by one-factor analysis of variance for different stages of POAG groups at each time of follow-up.
  
  
  RESULTS
  The baseline MD of visual field in POAG was (1.93 ± 1.66) dB in early group, (5.83 ± 1.95) dB in moderate group and (14.62 ± 3.53) dB in advanced group, respectively. At 24 months, MD in POAG was significant (F = 9.47, P < 0.05) increased to (7.24 ± 2.17) dB in moderate group, but not in other two groups (F = 2.03, 1.40; P > 0.05). Compared with baseline of total average RNFL thickness in POAG at temporal-superior-nasal-inferior-temporal [TSNIT: (53.72 ± 8.07) µm, (49.73 ± 7.16) µm, and (41.42 ± 8.30) µm in each group, respectively], RNFL thickness in each group was significant (F = 21.39, 18.65, 16.63; P < 0.05) decreased (50.43 ± 7.08) µm, (45.47 ± 6.50) µm, and (37.62 ± 7.28) µm (respectively) at 24 months. The inferior RNFL was significantly (F = 30.25, P < 0.05) reduced from (61.85 ± 9.77) µm to (54.35 ± 7.47) µm in early stage group, while the superior RNFL was changed more dramatically from (55.67 ± 9.50) µm to (49.75 ± 9.54) µm in moderate stage group (F = 31.72, P < 0.05). Both baselines of MD and RNFL thickness were significantly different in each group (F = 428.99, 21.32; P < 0.05).
  
  
  CONCLUSIONS
  Our results demonstrate that GDx-VCC system is useful to evaluate the progression of POAG in early and moderate stage by detecting the change of the RNFL thickness with long term follow up.
authors.affiliation: Department of Ophthalmology, Beijing hospital, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.forename: Xiao-wei
authors.initials: XW
authors.lastname: Liu
authors.forename: Xiao-yu
authors.initials: XY
authors.lastname: Li
authors.forename: Wen-ju
authors.initials: WJ
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Dai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009900:Optic Nerve / Q000473:pathology*; D012160:Retina / Q000473:pathology; D012189:Retrospective Studies; D057109:Scanning Laser Polarimetry; D014794:Visual Fields