title: Surgical and visual outcome following 20-gauge vitrectomy in proliferative diabetic retinopathy over a 10-year period, evidence for change in practice.
abstract: BACKGROUND
  The study reports 10-year anatomical and visual outcome in patients who underwent pars plana vitrectomy (PPV) for complications due to proliferative diabetic retinopathy (PDR).
  
  
  METHODS
  Retrospective analysis of patients undergoing 20 G PPV from January 1999 to May 2010 for tractional retinal detachment (TRD) and non-clearing vitreous hemorrhage (NCVH) secondary to PDR recorded prospectively on an electronic patient record. The primary aim was to study anatomical success and eyes with visual acuity (VA) of ≤ 0.3 logMAR at last follow-up.
  
  
  RESULTS
  There were 346 eyes of 249 patients with mean age of 55.63 years and follow-up of 1.44 years. In all, 95.3% of eyes had a flat retina at final follow-up. Overall 136/346 (39.4%) eyes had final VA of logMAR ≤ 0.3 (Snellen 6/12) and 129 (37.3%) had logMAR ≥ 1.0 (Snellen 6/60). In all, 50/181 (27.6%) eyes with TRD and 84/165 (50.9%) with NCVH achieved final VA of ≤ 0.3 logMAR (Snellen 6/12). A total of 218 (63.1%) showed ≥ 0.3 logMAR improvement from baseline to last follow-up. Both preoperative VA and final postoperative (post-op) VA (P<0.001) improved significantly with each year from 1999 to 2010. The commonest peroperative complication was iatrogenic retinal tear formation (28.4%). This was a risk factor for the development of post-op retinal detachment, odds ratio: 3.90 (95% confidence interval: 1.91-7.97, P = 0.0002). Silicone oil was used in 5.2% of patients at the primary procedure. In all, 9.2% required removal of non clearing post vitrectomy hemorrhage.
  
  
  CONCLUSIONS
  Outcomes from vitreoretinal surgery for complications of diabetic retinopathy have improved. In addition, the visual outcome after diabetic vitrectomy steadily improved over the 10-year period, which may in part be due to the move to operate on patients with better vision.
authors.affiliation: St Thomas' Hospital, London, UK.
authors.forename: B
authors.initials: B
authors.lastname: Gupta
authors.forename: R
authors.initials: R
authors.lastname: Wong
authors.forename: S
authors.initials: S
authors.lastname: Sivaprasad
authors.forename: T H
authors.initials: TH
authors.lastname: Williamson
mesh_terms: D000328:Adult; D000368:Aged; D003930:Diabetic Retinopathy / Q000150:complications / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012160:Retina / Q000473:pathology; D012163:Retinal Detachment / Q000209:etiology / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D014821:Vitrectomy / Q000379:methods*