title: Ischemic optic neuropathy in male veterans prescribed phosphodiesterase-5 inhibitors.
abstract: OBJECTIVE
  To determine the feasibility of a case-control study of phosphodiesterase (PDE)-5 inhibitors and nonarteritic ischemic optic neuropathy (NION).
  
  
  METHODS
  Retrospective cohort study using the National Veterans Health Administration's pharmacy and clinical databases.
  
  
  METHODS
  setting: National database. patient population: Male veterans 50 years of age and older with newly diagnosed NION or "possible" NION. interventional procedure: Dispensed prescription for a PDE-5 inhibitor. outcome measure: Incidence of NION and "possible" NION based on exposure to PDE-5 inhibitors.
  
  
  RESULTS
  The relative risk of NION among men prescribed a PDE-5 inhibitor was 1.02 (95% confidence interval [CI]: 0.92 to 1.12). The relative risk of possible NION among men prescribed a PDE-5 inhibitor was 1.34 (95% CI: 1.17 to 1.55).
  
  
  CONCLUSIONS
  The collective risk of NION and possible NION was marginally significant (relative risk [RR] 1.10 95% CI: 1.02 to 1.20). A case-control study, in which the dependent variable is NION and the effect size of the PDE-5 inhibitor is assumed small, is feasible.
authors.affiliation: University of South Florida College of Medicine, Tampa, Florida 33612, USA. cemargo@mindspring.com
authors.forename: Curtis E
authors.initials: CE
authors.lastname: Margo
authors.forename: Dustin D
authors.initials: DD
authors.lastname: French
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D016022:Case-Control Studies; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; D016208:Databases, Factual / Q000706:statistics & numerical data; D011307:Drug Prescriptions; D007172:Erectile Dysfunction / Q000188:drug therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D018917:Optic Neuropathy, Ischemic / Q000139:chemically induced* / Q000453:epidemiology; D010726:Phosphodiesterase Inhibitors / Q000009:adverse effects*; D010879:Piperazines / Q000009:adverse effects*; D011687:Purines / Q000009:adverse effects; D012189:Retrospective Studies; D012307:Risk Factors; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000009:adverse effects*; D014481:United States; D014493:United States Department of Veterans Affairs / Q000706:statistics & numerical data; D014728:Veterans
chemical_list: D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; C517381:PDE5A protein, human