title: Risk factors for a postoperative intraocular pressure spike after phacoemulsification.
abstract: BACKGROUND
  The aim of our study was to examine several potential risk factors for intraocular pressure (IOP) spikes 2 to 3 hours after phacoemulsification.
  
  
  METHODS
  50 eyes of 50 consecutive patients undergoing uncomplicated phacoemulsification under topical anesthesia were included in this prospective study. The following variables were recorded: preoperative IOP, nuclear colour, cortical lens opacity, posterior subcapsular lens opacity, patient age; and presence or absence of preexisting glaucoma.
  
  
  RESULTS
  The mean IOP at each time interval was as follows: preoperatively, 14.5 (SD 3.4) mm Hg; 2-3 hours postoperatively, 23.1 (7.0) mm Hg; and 24 hours postoperatively, 17.0 (6.0) mm Hg. The postoperative IOP was significantly higher than baseline at 2-3 hours (p<0.001) and at 24 hours (p=0.002). Overall there were 10 cases (20%) of IOP spikes 2-3 hours postoperatively. Higher mean baseline IOP was significantly associated with postoperative IOP spikes (p=0.013). Patient age, sex, operating surgeon, absolute phacoemulsification time, lens nuclear colour, cortical opacity, and posterior opacity were not significantly different between groups with or without an IOP spike (p>0.05).
  
  
  CONCLUSIONS
  Patients with high IOP at the preoperative assessment are more likely to have IOP spikes after surgery and should be scheduled at the start of the operating list. In a day-case setting with restricted opening hours, postoperative checks in those patients at risk of IOP spikes can then coincide with the time IOP reaches its peak.
authors.affiliation: Eye Department, Royal Victoria Eye & Ear Hospital, and the Department of Public Health Medicine and Epidemiology, University College Dublin, Ireland. mrpaulobrien@mac.com
authors.forename: Paul D
authors.initials: PD
authors.lastname: O'Brien
authors.forename: Su Ling
authors.initials: SL
authors.lastname: Ho
authors.forename: Patricia
authors.initials: P
authors.lastname: Fitzpatrick
authors.forename: William
authors.initials: W
authors.lastname: Power
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000772:Anesthesia, Local / Q000379:methods; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000209:etiology*; D018918:Phacoemulsification; D011183:Postoperative Complications; D011446:Prospective Studies; D012307:Risk Factors