Determination of the state and content of water in normal avian, fish, porcine, bovine, and human lenses as studied by differential scanning calorimetry.

Differential scanning calorimetry was used to measure the relative amounts of 'bulk' and 'bound' water in normal avian, bovine, fish, human, and porcine lenses. The amounts of bound water (mg bound water/mg lens dry weight) found in avian and porcine lenses were statistically different from each other in addition to being statistically different from fish, human, and bovine lenses. There were no significant differences in the mean values between human, fish, and bovine lenses. Avian lenses had the highest amount of bound water, while fish lenses had the lowest bound water content. Significant differences in total water content (mg total water/mg lens dry weight) were observed between all of the lenses, with the exception of bovine and human lenses which were not statistically different. Fish lenses had the lowest amount of total water, and avian lenses had the highest total water content. There were significant differences in bulk water content (mg bulk water/mg lens dry weight) between all of the lenses. Avian lenses had the highest bulk water content, and fish lenses had the lowest bulk water content.