title: High-frequency ultrasound biomicroscopy of the anterior segment morphometry before and immediately after pars plana vitrectomy.
abstract: OBJECTIVE
  To characterize short-term changes induced by pars plana vitrectomy on anterior segment depth and lens thickness by means of high-frequency ultrasound biomicroscopy.
  
  
  METHODS
  We undertook a prospective case series study on consecutive patients referred for pars plana vitrectomy as the sole procedure in our institution between 2005 and 2007. Twenty-eight eyes of 28 patients undergoing pars plana vitrectomy were studied by ultrasound biomicroscopy. Neither silicone oil nor scleral buckle was used for any of the procedures. Anterior chamber depth and lens thickness were compared before and immediately after surgery, and their results were compared to the postoperative intraocular pressure measurements.
  
  
  RESULTS
  There was a significant decrease in anterior chamber depth in the study eyes of patients who had undergone gas tamponade (p<0.0001) but not in those who had not undergone gas tamponade. No differences were found between the preoperative and the postoperative lens thickness measurements in any of the patients, nor was there any correlation between anterior chamber depth and increased intraocular pressure.
  
  
  CONCLUSIONS
  Uncomplicated pars plana vitrectomy with gas tamponade can induce short-term changes in anterior chamber depth as measured by morphometry. Surgeons may need to reconsider using gas tamponade at the end of surgery in surgical candidates with shallow anterior chambers.
authors.affiliation: Department of Ophthalmology, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Meira
authors.initials: M
authors.lastname: Neudorfer
authors.forename: Nir
authors.initials: N
authors.lastname: Oren
authors.forename: Adiel
authors.initials: A
authors.lastname: Barak
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000867:Anterior Chamber / Q000473:pathology*; D002924:Ciliary Body / Q000000981:diagnostic imaging*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D007908:Lens, Crystalline / Q000000981:diagnostic imaging*; D008297:Male; D033401:Microscopy, Acoustic; D008875:Middle Aged; D011184:Postoperative Period; D057234:Preoperative Period; D011446:Prospective Studies; D012164:Retinal Diseases / Q000601:surgery*; D014821:Vitrectomy