Abstract
Purpose: :
Although mice have become an increasingly important model for ophthalmologic research, their lens transmission properties have not been examined in detail. In this study, we measured the lens attenuation spectra from albino and pigmented mice from 350nm to 1050nm and compared them with three other species: rat, porcine, and human.
Methods: :
Pigmented C57BL/6 and albino balb/c mice (eight in each group) of 3–5 month old were used in the study. Transmission spectra of extracted lenses were measured using an integrating sphere equipped with a spectrometer. The thickness and diameter of each lens were also measured from calibrated digital pictures. The attenuation coefficients were calculated based on Beer–Lambertian law. Attenuation spectra were also measured for lenses of 7–week–old Sprague–Dawley rats, 4–month–old domestic pigs, and human subjects.
Results: :
The albino mouse has very similar attenuation spectra as rat. Albino mice show systematically smaller attenuation coefficients than black mice. The porcine lenses have smaller attenuation in the visible wavelengths, but larger attenuation in the UV region than the rodent lenses. The attenuation coefficients of human lenses are significantly larger than the other species in the whole bandwidth. As the wavelength increases, the attenuation coefficient decreases for all the four species from 350nm to 700nm. The attenuation coefficient increases after 700nm and forms a peak at about 920nm. Although the measured lens attenuation spectra have significant variations among the four species, they all can be well fitted with a composite equation consisting terms from chromophore absorption and scattering in the ultraviolet to visible bandwidth (350nm∼700nm). In the near infrared region (700nm∼1050nm), water absorption has to be included to explain the measurements.
Conclusions: :
We have measured the thickness independent attenuation spectra of mouse crystalline lens and compared them with those of rat, pig and human. The derived analytic fitting equations facilitate the usage of these results in relevant vision studies.
Keywords: crystalline lens • optical properties