title: Positive End-Expiratory Pressure as a Risk Factor for Severe Positive Vitreous Pressure During Combined Penetrating Keratoplasty and Cataract Extraction.
abstract: OBJECTIVE
  To report the potential risk of severe positive vitreous pressure during combined penetrating keratoplasty, cataract extraction, and intraocular lens implantation (triple procedure), using positive end-expiratory pressure (PEEP) during general endotracheal anesthesia.
  
  
  METHODS
  This is a case report of a 32-year-old man and a 48-year-old man who underwent penetrating keratoplasty, extracapsular lens extraction, and intraocular lens implantation during which severe positive posterior pressure was encountered during the open-sky lens extraction.
  
  
  RESULTS
  In both cases, severe posterior vitreous pressure against an intact posterior capsule hindered intraocular lens implantation during the triple procedure. Despite exhaustive search for the cause of posterior pressure, no other risk factors were found other than the use of PEEP.
  
  
  CONCLUSIONS
  During open-sky procedures, PEEP may be a risk factor for severe positive posterior vitreous pressure. Given the rising use of PEEP, surgeons should be aware and cautious of this potential complication.
authors.affiliation: *Cole Eye Institute, Cleveland Clinic, Cleveland, OH; and †Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD.
authors.forename: Angelique
authors.initials: A
authors.lastname: Pillar
authors.forename: Bennie H
authors.initials: BH
authors.lastname: Jeng
authors.forename: Wuqaas M
authors.initials: WM
authors.lastname: Munir
mesh_terms: D000328:Adult; D002387:Cataract Extraction; D006801:Humans; D007429:Intraocular Pressure; D015948:Keratoplasty, Penetrating; D019654:Lens Implantation, Intraocular; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000209:etiology*; D011175:Positive-Pressure Respiration / Q000009:adverse effects*; D012307:Risk Factors; D014792:Visual Acuity; D014822:Vitreous Body / Q000473:pathology*