title: Study of ethane level in exhaled breath in patients with age-related macular degeneration: preliminary study.
abstract: OBJECTIVE
  A variety of factors have been implicated in the pathogenesis of age-related macular degeneration (ARMD), and oxidative stress plays an important role in the onset and progression of the disease. Breath ethane is now considered a specific and non-invasive test for determining and monitoring the trend of lipid peroxidation and free radical-induced damage in vivo. This test provides an index of the patients' overall oxidative stress level. We evaluated the breath ethane concentration in exhaled air in patients with advanced ARMD.
  
  
  METHODS
  In this study, we enrolled 13 patients with advanced ARMD and a control group, and a breath analysis was carried out by gas chromatography.
  
  
  RESULTS
  The mean ethane level in the ARMD patients was 0.82 ± 0.93 nmol/l (range: 0.01-2.7 nmol/l) and the mean ethane value in the control group was 0.12 ± 0.02 nmol/l (range: 0.08-0.16 nmol/l). The difference between the values of the 2 groups was statistically significant (p < 0.005). Receiver operating characteristic analysis showed an elevated area under the curve (0.831; 95% CI: 0.634-0.948), with a significance level of p < 0.0014 (area = 0.5).
  
  
  CONCLUSIONS
  These preliminary results seem to indicate that breath ethane levels are higher in most patients with ARMD. The breath ethane test could thus be a useful method for evaluating the level of oxidative stress in patients with ARMD. To our knowledge, there are no data on this type of analysis applied to ARMD.
authors.affiliation: Department of Ophthalmology, University of Perugia, Perugia, Italy. carlocagini@hotmail.com
authors.forename: C
authors.initials: C
authors.lastname: Cagini
authors.forename: A
authors.initials: A
authors.lastname: Giordanelli
authors.forename: T
authors.initials: T
authors.lastname: Fiore
authors.forename: R
authors.initials: R
authors.lastname: Giardinieri
authors.forename: B
authors.initials: B
authors.lastname: Malici
authors.forename: G E
authors.initials: GE
authors.lastname: De Medio
authors.forename: M A
authors.initials: MA
authors.lastname: Pelli
authors.forename: F
authors.initials: F
authors.lastname: De Bellis
authors.forename: E
authors.initials: E
authors.lastname: Capodicasa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests / Q000379:methods; D016022:Case-Control Studies; D002849:Chromatography, Gas; D004980:Ethane / Q000032:analysis*; D045853:Exhalation; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology; D012372:ROC Curve
chemical_list: D015415:Biomarkers; D004980:Ethane