title: Cryotherapy of the anterior retina and sclerotomy sites in diabetic vitrectomy to prevent recurrent vitreous hemorrhage: an ultrasound biomicroscopy study.
abstract: OBJECTIVE
  To evaluate the role of cryotherapy of the anterior retina and sclerotomy sites in the prevention of fibrovascular ingrowth (FVIG) at sclerotomy sites and postoperative recurrent vitreous hemorrhage in patients undergoing pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR).
  
  
  METHODS
  Retrospective, nonrandomized, observational case series.
  
  
  METHODS
  Eighty-one eyes in 71 patients who had undergone PPV for complications of PDR in the previous 2 years, with postoperative retinal reattachment for at least 3 months.
  
  
  METHODS
  Cases were divided into 3 groups: (1) having panretinal or supplementary endophotocoagulation; (2) having anterior peripheral retinal cryotherapy (ARC) in addition to panretinal endolaser treatment; and (3) having endophotocoagulation, ARC, and cryotherapy on the 3 sclerotomy sites added. Ultrasound biomicroscopy (UBM) examination of the 3 sclerotomy sites was performed > or =2 months after surgery. The UBM findings were separated into 4 categories: well-healed, gap, vitreous incarceration, and FVIG. History and management of recurrent vitreous hemorrhage were recorded.
  
  
  METHODS
  Ultrasound biomicroscopy findings and the percentage of recurrent vitreous hemorrhage in the 3 groups were compared to determine the effectiveness of the adjunct cryotherapy in inhibiting FVIG and preventing recurrent vitreous hemorrhage.
  
  
  RESULTS
  The recurrent vitreous hemorrhage rates in groups 1, 2, and 3 were 12 of 32 (37.5%), 3 of 26 (11.5%), and 1 of 23 (4.3%), respectively (P = 0.0004). In each group, different sclerotomy sites had similar distributions of the 4 UBM categories. Among the 3 groups, gap was found in 9.4%, 20.5%, and 52.2% of eyes, respectively (P<0.001), whereas FVIG was found in 36.5%, 15.4%, and 0% of eyes (P<0.001). Fibrovascular ingrowth was noted in 87.5% (14/16) of all eyes experiencing recurrent vitreous hemorrhage. Of those with rebleeding but no FVIG (2 eyes), 1 had vitreous lavage combined with additional cryotherapy, and 1 had no treatment. Of those with FVIG (14 eyes), 5 needed > or =2 operations.
  
  
  CONCLUSIONS
  The presence of FVIG had good correlation with the development of recurrent postoperative vitreous hemorrhage. Anterior peripheral retinal cryotherapy combined with cryotherapy of sclerotomy sites might be helpful adjunct procedures in diabetic vitrectomy for inhibition of FVIG and prevention of recurrent vitreous hemorrhage.
authors.affiliation: Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Po-Ting
authors.initials: PT
authors.lastname: Yeh
authors.forename: Chung-May
authors.initials: CM
authors.lastname: Yang
authors.forename: Chang-Hao
authors.initials: CH
authors.lastname: Yang
authors.forename: Jen-Shang
authors.initials: JS
authors.lastname: Huang
mesh_terms: D017679:Cryotherapy / Q000379:methods*; D003930:Diabetic Retinopathy / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D005355:Fibrosis / Q000000981:diagnostic imaging / Q000517:prevention & control; D006801:Humans; D017075:Laser Coagulation; D008297:Male; D033401:Microscopy, Acoustic; D008875:Middle Aged; D011183:Postoperative Complications / Q000517:prevention & control; D012160:Retina / Q000000981:diagnostic imaging / Q000601:surgery*; D012189:Retrospective Studies; D012590:Sclera / Q000000981:diagnostic imaging / Q000601:surgery*; D012599:Sclerostomy; D055502:Secondary Prevention; D014821:Vitrectomy; D014823:Vitreous Hemorrhage / Q000000981:diagnostic imaging / Q000517:prevention & control*