Laser light scattering spectroscopy of in vivo human lenses.

Laser light scattering spectroscopy measures the thermal random movement of protein as characterized by the diffusion coefficient. This technique has been used in assessing cataract formation in animals. The changes detected appear to predict the later development of lens opacities. The sensitivity and quantitative aspects of this technique offer advantages over other presently available methods of detecting cataract formation. First studies in humans indicated a significant correlation between the diffusion coefficient and age (P less than 0.05). The age adjusted mean diffusion coefficient for nondiabetics (4.60 +/- 0.29; mean +/- SEM) was significantly higher compared to diabetics without retinopathy (3.59 +/- 0.41; P = 0.0473), diabetics with background or preproliferative retinopathy (2.73 +/- 0.27; P = 0.0001), or to diabetics with preproliferative or proliferative retinopathy receiving laser photocoagulation within 1 year of measurement (3.02 +/- 0.37; P = 0.0012). Diabetics with laser treatment more than 1 year prior to measurement (3.96 +/- 0.51) did not differ significantly from nondiabetics.