Clinical detection of precataractous lens protein changes using dynamic light scattering.
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.
Datiles
Manuel B
MB
National Eye Institute, NIH, Bethesda, MD 20892-1860, USA. datilesm@nei.nih.gov
Ansari
Rafat R
RR
Suh
Kwang I
KI
Vitale
Susan
S
Reed
George F
GF
Zigler
J Samuel
JS
Ferris
Frederick L
FL
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*
D038201:alpha-Crystallins