title: [Advantages and disadvantages of the circumferential retinal cryocoagulation before vitrectomy in proliferative diabetic vitreoretinopathy].
abstract: BACKGROUND
  It is unclear if a circumferential cryocoagulation 4 weeks before pars plana vitrectomy is useful for reducing the risks of surgery such as retinal detachment, secondary glaucomas or rebleeding. Otherwise it seems possible that this surgery itself, done in local anaesthesia, could be an additional risk.
  
  
  METHODS
  We retrospectively evaluated the reports of all patients who underwent vitrectomy as primary surgery due to proliferative diabetic vitreoretinopathy between 1997 and 2000. Besides age and sex, all additional surgery (like phacoemulsification, endolaser coagulation, kind of tamponade etc.) and all intra- or postoperative complications were reported after a follow-up of at least 3 months. We created and compared 2 groups of patients, showing in group 1 patients who underwent vitrectomy 4 weeks after cryocoagulation and in group 2 patients undergoing vitrectomy combined with circumferential cryocoagulation.
  
  
  RESULTS
  We evaluated the reports of 226 patients (103 men, 123 women, mean age 58.6 +/- 13.0 years). Follow-up was in the mean 16.3 months. Group 1 contained 150 patients (66.4 %), group 2 76 patients (33.6 %). 63.7 % received air as endotamponade, 8.0 % C(2)F(6) gas, 7.1 % silicon oil and 21.2 % BSS, 34.1 % were operated in combination with phakoemulsification. We observed 9 postoperative retinal detachments (4.0 %), with no significant difference between the two groups (6 detachments in group 1, 2 detachments in group 2). For other surgical risks like rebleeding, rubeosis iridis, secondary glaucoma etc. we also found no statistically significant differences.
  
  
  CONCLUSIONS
  Circumferential retinal cryocoagulation is a useful preparation before pars plana vitrectomy, when done due to vitreous haemorrhage, because improved resorption lowers the vitrectomy rate. In all other cases it can be done during vitrectomy. Adjuvant circumferential cryocoagulation seems to decrease the risk of postoperative retinal detachments and rebleedings as documented in literature comparison.
authors: Augenklinik des Universitätsklinikums Giessen und Marburg, Standort Marburg. schulzes@med.uni-marburg.de
authors: S
authors: S
authors: Schulze
authors: N
authors: N
authors: Zaki
authors: P
authors: P
authors: Kroll
mesh_terms: D003131:Combined Modality Therapy; D017679:Cryotherapy / Q000379:methods*; D003930:Diabetic Retinopathy / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D014821:Vitrectomy / Q000379:methods*; D018630:Vitreoretinopathy, Proliferative / Q000628:therapy*