Determination of Water Content in Bovine Lenses Using Near-Infrared Spectroscopy

Abstract

Near-infrared spectral data of bovine nuclear lens tissue was collected in the 3,500- to 6,500-cm^––1 frequency range. The intensity ratios of the water peak at 5,194 cm^––1 to characteristic protein peaks at 4,862, 4,599, and 4,368 cm^––1 were determined for the nucleus of bovine lens samples. The water and protein mass percentages were determined by using a calibration curve established by spectra obtained from aqueous solutions with various concentrations of bovine serum albumin. The bovine fetal nucleus was found to contain 61.2 ± 1.6, 61.2 ± 1.9, and 58.4 ± 1.9 water using the ratio of the water peak intensity to each of the three characteristic protein peaks within each spectrum. These results are consistent with other analytical techniques, thus showing the accuracy of this technique for obtaining chemical information on lens tissue.

Evidence for Distinct Cholesterol Domains in Fiber Cell Membranes from Cataractous Human Lenses

“…One possible explanation of this phenomenon is that optimum structural organization in the lens is achieved at a lower water content. The average water content of the human lens is ϳ65% (57), and maintenance of proper hydration levels is crucial for optimal refractive power and lens function (58). At 52% RH, the water space between the sample membrane bilayers would be diminished, perhaps imitating the minimized extracellular spaces between the tightly juxtaposed cells of the ocular lens.…”