title: Lens Position Parameters as Predictors of Intraocular Pressure Reduction After Cataract Surgery in Nonglaucomatous Patients With Open Angles.
abstract: OBJECTIVE
  To evaluate the relationship between lens position parameters and intraocular pressure (IOP) reduction after cataract surgery in nonglaucomatous eyes with open angles.
  
  
  METHODS
  The main outcome of the prospective study was percentage of IOP change, which was calculated using the preoperative IOP and the IOP 4 months after cataract surgery in nonglaucomatous eyes with open angles. Lens position (LP), defined as anterior chamber depth (ACD) + 1/2 lens thickness (LT), was assessed preoperatively using parameters from optical biometry. Preoperative IOP, central corneal thickness, ACD, LT, axial length (AXL), and the ratio of preoperative IOP to ACD (PD ratio) were also evaluated as potential predictors of percentage of IOP change. The predictive values of the parameters we found to be associated with the primary outcome were compared.
  
  
  RESULTS
  Four months after cataract surgery, the average IOP reduction was 2.03 ± 2.42 mm Hg, a 12.74% reduction from the preoperative mean of 14.5 ± 3.05 mm Hg. Lens position was correlated with IOP reduction percentage after adjusting for confounders (P = 0.002). Higher preoperative IOP, shallower ACD, shorter AXL, and thicker LT were significantly associated with percentage of IOP decrease. Although not statistically significant, LP was a better predictor of percentage of IOP change compared to PD ratio, preoperative IOP, and ACD.
  
  
  CONCLUSIONS
  The percentage of IOP reduction after cataract surgery in nonglaucomatous eyes with open angles is greater in more anteriorly positioned lenses. Lens position, which is convenient to compute by basic ocular biometric data, is an accessible predictor with considerable predictive value for postoperative IOP change.
authors.affiliation: Department of Ophthalmology University of California-San Francisco, San Francisco, California, United States 2Department of Ophthalmology, Taipei Medical University, Shuang Ho Hospital, New Taipei City, Taiwan.
authors.forename: Chi-Hsin
authors.initials: CH
authors.lastname: Hsu
authors.affiliation: Department of Ophthalmology University of California-San Francisco, San Francisco, California, United States.
authors.forename: Caitlin L
authors.initials: CL
authors.lastname: Kakigi
authors.affiliation: Department of Ophthalmology University of California-San Francisco, San Francisco, California, United States.
authors.forename: Shuai-Chun
authors.initials: SC
authors.lastname: Lin
authors.affiliation: Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan 4Department of Medical Research, Taipei Medical University, Shuang Ho Hospital, New Taipei City, Taiwan.
authors.forename: Yuan-Hung
authors.initials: YH
authors.lastname: Wang
authors.affiliation: Department of Epidemiology and Biostatistics, University of California-San Francisco, San Francisco, California, United States.
authors.forename: Travis
authors.initials: T
authors.lastname: Porco
authors.affiliation: Department of Ophthalmology University of California-San Francisco, San Francisco, California, United States.
authors.forename: Shan C
authors.initials: SC
authors.lastname: Lin