title: Clinical detection of precataractous lens protein changes using dynamic light scattering.
abstract: OBJECTIVE
  To use dynamic light scattering to clinically assess early precataractous lens protein changes.
  
  
  METHODS
  We performed a cross-sectional study in 380 eyes of 235 patients aged 7 to 86 years with Age-Related Eye Disease Study clinical nuclear lens opacity grades 0 to 3.8. A dynamic light-scattering device was used to assess alpha-crystallin, a molecular chaperone protein shown to bind other damaged lens proteins, preventing their aggregation. The outcome measure was the alpha-crystallin index, a measure of unbound alpha-crystallin in each lens. The association of the alpha-crystallin index with increasing nuclear opacity and aging was determined.
  
  
  RESULTS
  There was a significant decrease in the alpha-crystallin index associated with increasing nuclear lens opacity grades (P < .001). There were significant losses of alpha-crystallin even in clinically clear lenses associated with aging (P < .001). The standard error of measurement was 3%.
  
  
  CONCLUSIONS
  Dynamic light scattering clinically detects alpha-crystallin protein loss even in clinically clear lenses. alpha-Crystallin index measurements may be useful in identifying patients at high risk for cataracts and as an outcome variable in clinical lens studies.
  
  
  CONCLUSIONS
  The alpha-crystallin index may be a useful measure of the protective alpha-crystallin molecular chaperone reserve present in a lens, analogous to creatinine clearance in estimating renal function reserve.
authors.affiliation: National Eye Institute, NIH, Bethesda, MD 20892-1860, USA. datilesm@nei.nih.gov
authors.forename: Manuel B
authors.initials: MB
authors.lastname: Datiles
authors.forename: Rafat R
authors.initials: RR
authors.lastname: Ansari
authors.forename: Kwang I
authors.initials: KI
authors.lastname: Suh
authors.forename: Susan
authors.initials: S
authors.lastname: Vitale
authors.forename: George F
authors.initials: GF
authors.lastname: Reed
authors.forename: J Samuel
authors.initials: JS
authors.lastname: Zigler
authors.forename: Frederick L
authors.initials: FL
authors.lastname: Ferris
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology; D000818:Animals; D002386:Cataract / Q000145:classification / Q000175:diagnosis*; D002417:Cattle; D002648:Child; D003430:Cross-Sectional Studies; D006801:Humans; D007908:Lens, Crystalline / Q000737:chemistry*; D008027:Light; D008875:Middle Aged; D011446:Prospective Studies; D012542:Scattering, Radiation; D038201:alpha-Crystallins / Q000032:analysis*
chemical_list: D038201:alpha-Crystallins