The quality and sensitivity of lens scatter densitometry with a computerized Scheimpflug video camera

Densitometry based on Scheimpflug imaging can be used to noninvasively evaluate light scatter changes in the human lens. We have evaluated a new commercial Scheimpflug camera based on digitization of video images. The in vivo reproducibility was best (6.5%) for densitometric measurements averaged along the central section of the lens and including all areas from the anterior to the posterior surfaces. The spatial resolution was 0.2 mm. Tests performed in vitro indicated that densimetric readings of central and posterior layers of the lens prone to artifactual reductions due to loss of light anteriorly. The dependence of the human lens densitometric readings on age was assessed in 17 subjects. The results indicated that this instrument can detect a change of 13%, which is statistically significant, and that such a change can be expected over three years in normal clear lenses.