title: Selenium and pseudoexfoliation syndrome.
abstract: OBJECTIVE
  To investigate the levels of selenium (Se), an essential trace element, in aqueous humor, conjunctival specimens, and serum of patients with pseudoexfoliation (PEX) syndrome and control subjects; and to determine the role of Se in the development and pathogenesis of PEX syndrome.
  
  
  METHODS
  A prospective case-control study.
  
  
  METHODS
  Twenty-seven cataract patients with PEX syndrome and 20 age-matched cataract patients without PEX syndrome were enrolled in this institutional study. Patients with ophthalmic conditions other than PEX and conditions that may influence Se levels were excluded. During cataract surgeries, aqueous humor, conjunctival specimens, and serum were collected in both groups. Selenium levels of all samples were measured by using atomic absorption spectrophotometer.
  
  
  RESULTS
  The mean Se levels in aqueous humor of patients with PEX syndrome (50.96 ± 23.79 μg/L) were significantly lower than the control group (77.85 ± 19.21 μg/L) (P < .001). The mean Se levels in conjunctival specimens of patients with PEX syndrome (4.04 ± 1.44 μg/mg) were significantly lower than the control group (7.19 ± 2.00 μg/mg) (P < .001), as well. The mean Se levels in serum of patients with PEX syndrome (115.25 ± 25.20 μg/L) were lower than the control group (124.25 ± 14.40 μg/L), but this was not statistically significant (P = .325).
  
  
  CONCLUSIONS
  Reduced levels of Se in aqueous humor, conjunctival specimens, and serum of patients with PEX may support the role of impairment in antioxidant defense system in the pathogenesis of PEX syndrome.
authors.affiliation: Department of Ophthalmology, Mersin University Faculty of Medicine, Mersin, Turkey. aycayilmaz@yahoo.com
authors.forename: Ayça
authors.initials: A
authors.lastname: Yilmaz
authors.forename: Lokman
authors.initials: L
authors.lastname: Ayaz
authors.forename: Lülüfer
authors.initials: L
authors.lastname: Tamer
mesh_terms: D000368:Aged; D001082:Aqueous Humor / Q000378:metabolism*; D002386:Cataract / Q000097:blood; D003228:Conjunctiva / Q000378:metabolism*; D017889:Exfoliation Syndrome / Q000097:blood*; D006801:Humans; D011446:Prospective Studies; D012643:Selenium / Q000378:metabolism*; D013054:Spectrophotometry, Atomic; D014131:Trace Elements / Q000378:metabolism*
chemical_list: D014131:Trace Elements; D012643:Selenium