title: The effect of cataract surgery on diurnal intraocular pressure fluctuation.
abstract: OBJECTIVE
  We examined prospectively the effects of cataract surgery on diurnal intraocular pressure (IOP) fluctuation in patients without glaucoma.
  
  
  METHODS
  We evaluated 42 eyes from 42 patients without glaucoma that underwent clear corneal phacoemulsification and intraocular lens implantation by the same surgeon without complications. The diurnal IOP was measured using a Goldmann applanation tonometer the day before surgery and at least 4 weeks after surgery. The diurnal IOP was measured from 9 AM to 11 PM every 2 hours by the same clinician.
  
  
  RESULTS
  The mean age of the 14 men and 28 women was 69.7+/-7.6 (SD) years. The mean preoperative IOP was 12.2+/-2.5 mm Hg. Postoperatively, the mean IOP was 10.7+/-2.1 mm Hg. The maximum IOP was significantly decreased from the mean preoperative level of 13.7+/-2.7 mm Hg to 12.3+/-2.7 mm Hg at follow-up. The minimum IOP was also significantly decreased from 10.9+/-2.7 mm Hg to 9.7+/-2.1 mm Hg. Cataract surgery reduced IOP significantly at all measurement time points (P<0.05). However, there was no significant difference in the range of IOP before (2.8+/-1.3 mm Hg) and after (2.7+/-1.5 mm Hg) surgery (P=0.498).
  
  
  CONCLUSIONS
  We found a significant decrease in IOP after cataract surgery in nonglaucoma patients. However, change of diurnal IOP fluctuation after surgery was not statistically different. These results can be used as baseline data for diurnal IOP fluctuation studies in glaucoma patients after cataract surgery.
authors.affiliation: Department of Ophthalmology, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, 108 Pyeong-Dong, Jongno-Gu, Seoul, South Korea.
authors.forename: Kwan Soo
authors.initials: KS
authors.lastname: Kim
authors.forename: Joon Mo
authors.initials: JM
authors.lastname: Kim
authors.forename: Ki Ho
authors.initials: KH
authors.lastname: Park
authors.forename: Chul Young
authors.initials: CY
authors.lastname: Choi
authors.forename: Hae Ran
authors.initials: HR
authors.lastname: Chang
mesh_terms: D000368:Aged; D002387:Cataract Extraction / Q000379:methods; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D019654:Lens Implantation, Intraocular; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification; D011184:Postoperative Period; D011446:Prospective Studies