title: Severe proliferative diabetic retinopathy treated with vitrectomy or panretinal photocoagulation: a monocenter randomized controlled clinical trial.
abstract: OBJECTIVE
  Visual and anatomic results of pars plana vitrectomy were compared with panretinal photocoagulation in cases of severe proliferative diabetic retinopathy.
  
  
  METHODS
  Monocenter randomized controlled clinical trial; randomization and allocation to trial group were carried out by a central computer system.
  
  
  METHODS
  We studied 180 eyes of 180 patients with severe proliferative diabetic retinopathy, half with tractional retinal detachment not involving the macula (n = 90). Some were treated by pars plana vitrectomy (n = 90) and some by panretinal photocoagulation (n = 90).
  
  
  METHODS
  Eyes were randomly divided into 2 groups. Group 1 was treated with pars plana vitrectomy, membrane and internal limited membrane peeling, panretinal photocoagulation, and focal or grid macular laser. Group 2 was treated with panretinal photocoagulation and focal or grid macular laser. Follow-up was at least 12 months.
  
  
  RESULTS
  Mean preoperative visual acuities and ophthalmic fundus characteristics were compared across groups. A year postoperation, visual acuity (the primary endpoint) in group 1 improved in 30 eyes (33%); was unchanged in 22 eyes (25%); and decreased in 38 eyes (42%). In group 2, visual acuity improved in 32 eyes (35%); was unchanged in 42 eyes (47%); and decreased in 16 eyes (18%). The percentage of improvement in the 2 groups was not statistically significant (p = 0.75), whereas the stabilized (p = 0.002) and worsened eyes (p = 0.0003) in group 1 and group 2 were significantly different.
  
  
  CONCLUSIONS
  In cases of severe proliferative diabetic retinopathy, even with tractional retinal detachment not involving macula, it is best to defer vitrectomy unless definite progression that threatens the vascular center is documented.
authors.affiliation: Department of Medicine and Surgery, Section of Ophthalmology, Santa Marta Hospital, University of Catania, Italy. t.avitabile@unict.it
authors.forename: Teresio
authors.initials: T
authors.lastname: Avitabile
authors.forename: Vincenza
authors.initials: V
authors.lastname: Bonfiglio
authors.forename: Francesco
authors.initials: F
authors.lastname: Castiglione
authors.forename: Marine
authors.initials: M
authors.lastname: Castaing
authors.forename: Fabio
authors.initials: F
authors.lastname: Contarino
authors.forename: Antonio
authors.initials: A
authors.lastname: Mistretta
mesh_terms: D000328:Adult; D000368:Aged; D003930:Diabetic Retinopathy / Q000503:physiopathology / Q000601:surgery*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007431:Intraoperative Complications; D017075:Laser Coagulation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011446:Prospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D014821:Vitrectomy / Q000379:methods*; D055815:Young Adult