title: Anterior chamber collapse following vitreoretinal surgery with gas tamponade in aphakic eyes: incidence and risk factors.
abstract: OBJECTIVE
  To report the risk factors associated with occurrence of anterior chamber collapse in aphakic eyes that underwent vitrectomy with gas tamponade.
  
  
  METHODS
  A total of 314 eyes of 314 patients who underwent vitrectomy with gas tamponade and who were aphakic or were made aphakic intraoperatively were studied prospectively. Factors such as iris and pupillary integrity, depth of anterior chamber, gonioscopic grading, behavior of the anterior chamber on the operation table during fluid-air exchange, removal of crystalline lens or intraocular lens during surgery, and type of internal tamponade were noted. The anterior chamber was assessed postoperatively in supine and sitting position and with head bent forward. Statistical methods were used to identify risk factors for development of postoperative anterior chamber collapse using SPSS soft ware.
  
  
  RESULTS
  Anterior chamber collapse occurred in 13 eyes (3.14%). Presence of preoperative shallow anterior chamber, removal of intraocular lens as a part of the procedure, occurrence of intraoperative anterior chamber collapse, and use of sulfur hexafluoride (SF6) were associated with higher risk of anterior chamber collapse postoperatively.
  
  
  CONCLUSIONS
  The identification of potential risk factors in a given eye can alert the surgeon to the possibility of development of anterior chamber collapse postoperatively.
authors.affiliation: Department of Vitreoretinal Services, Sankara, Nethralaya, Chennai, India. drlg@snmail.org
authors.forename: Lingam
authors.initials: L
authors.lastname: Gopal
authors.forename: Amit
authors.initials: A
authors.lastname: Nagpal
authors.forename: Sachin
authors.initials: S
authors.lastname: Kabra
authors.forename: Joseph
authors.initials: J
authors.lastname: Roy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000867:Anterior Chamber / Q000473:pathology*; D001036:Aphakia, Postcataract / Q000150:complications*; D002648:Child; D005260:Female; D005466:Fluorocarbons / Q000008:administration & dosage*; D006068:Gonioscopy; D006801:Humans; D015994:Incidence; D007908:Lens, Crystalline / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011187:Posture; D011446:Prospective Studies; D012163:Retinal Detachment / Q000601:surgery*; D012307:Risk Factors; D013459:Sulfur Hexafluoride / Q000008:administration & dosage*; D014821:Vitrectomy
chemical_list: D005466:Fluorocarbons; C042852:perflutren; D013459:Sulfur Hexafluoride