title: Prevalence of normal tension glaucoma in obstructive sleep apnea syndrome patients.
abstract: OBJECTIVE
  To explore the prevalence of normal tension glaucoma (NTG) among patients with obstructive sleep apnea syndrome (OSAS) and to examine OSAS as a risk factor of NTG.
  
  
  METHODS
  Fifty-one consecutive white patients with OSAS were compared with 40 healthy subjects. All the study subjects underwent blood gas analysis, polysomnography, oxyhemoglobin saturation, and an ophthalmologic examination including visual field, visually evoked potential (VEP), and pattern electroretinography (PERG) and disc analysis with the Heidelberg Retina Tomograph II.
  
  
  RESULTS
  Three of 51 OSAS patients (5.9%) had NTG. No patient in the control group had OSAS or NTG. The severity of OSAS correlated with intraocular pressure, the mean deviation of the visual field, the cup/disk ratio and the mean of the retinal nerve fiber layer thickness (P<0.01 to 0.001). Apnea hypopnea index and intraocular pressure were significantly greater in OSAS patients with abnormal VEP and PERG, compared to those with normal PERG and VEP.
  
  
  CONCLUSIONS
  The present study suggests that the prevalence of NTG in our OSAS patients is higher than expected in a white population of the same age and that OSAS may be an important risk factor for NTG. Our data underline the importance of taking an accurate sleep history from patients with NTG and referring patients with sleep disturbance for polysomnography.
authors.affiliation: Unità Operativa di Fisiopatologia Respiratoria, Ospedale Luigi Sacco, Milano. fisiopatologia@hsacco.it
authors.forename: Margherita
authors.initials: M
authors.lastname: Sergi
authors.forename: Daniela Eva
authors.initials: DE
authors.lastname: Salerno
authors.forename: Maurizio
authors.initials: M
authors.lastname: Rizzi
authors.forename: Mirella
authors.initials: M
authors.lastname: Blini
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Andreoli
authors.forename: Dario
authors.initials: D
authors.lastname: Messenio
authors.forename: Marica
authors.initials: M
authors.lastname: Pecis
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Bertoni
mesh_terms: D001784:Blood Gas Analysis; D004596:Electroretinography; D005074:Evoked Potentials, Visual; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D010108:Oxyhemoglobins / Q000032:analysis; D017286:Polysomnography; D015995:Prevalence; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000175:diagnosis; D014794:Visual Fields
chemical_list: D010108:Oxyhemoglobins