title: Associated morbidity of nasolacrimal duct obstruction--a large community based case-control study.
abstract: BACKGROUND
  To evaluate the prevalence and risk factors of various conditions among patients with nasolacrimal duct obstruction (NLDO).
  
  
  METHODS
  A retrospective, observational case control study of 2,615 patients diagnosed with NLDO in the Central District of Clalit Health Services HMO in Israel, from 2003 to 2012; 15,650 control patients were randomly selected from the district HMO members. Medical and socio-demographic information were extracted from patients' electronic medical records. The prevalence of various ocular and systemic conditions as risk factors for NLDO was calculated.
  
  
  RESULTS
  The average age of NLDO patients was 68.3 ± 14.9 years, 34.4 % were male. Age (p < 0.001), ischemic heart disease (OR = 1.29; CI: 1.15-1.44), glaucoma (OR = 1.17; CI: 1.01-1.36), allergic conjunctivitis (OR = 3.59; CI: 3.28-3.94), dry eye (OR = 1.43; CI: 1.31-1.58), epiphora (OR = 6.34; CI: 5.09-7.91), and allergic rhinitis (OR = 1.51; CI: 1.33-1.71) were significantly associated with NLDO. Smoking (OR = 0.86; CI: 0.77-0.96) was significantly less prevalent among NLDO patients.
  
  
  CONCLUSIONS
  The etiology of NLDO is multifactorial. The prevalence of associated demographic, systemic, and periocular conditions varies. A better understanding of the patho-physiological association between these factors and NLDO may help its prevention and treatment.
authors.affiliation: Department of Ophthalmology, Meir Medical Center, Kfar Saba, 44281, Israel, nemet.arik@gmail.com.
authors.forename: Arie Y
authors.initials: AY
authors.lastname: Nemet
authors.forename: Shlomo
authors.initials: S
authors.lastname: Vinker
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003920:Diabetes Mellitus / Q000453:epidemiology; D005128:Eye Diseases / Q000453:epidemiology; D005260:Female; D006279:Health Maintenance Organizations / Q000706:statistics & numerical data; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007557:Israel / Q000453:epidemiology; D007767:Lacrimal Duct Obstruction / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D017202:Myocardial Ischemia / Q000453:epidemiology; D009301:Nasolacrimal Duct / Q000473:pathology*; D009765:Obesity / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology