Dimethyl sulfoxide cataract

Purpose. Rat lenses incubated in dimethyl sulfoxide (DMSO)-water binary mixtures of different compositions become turbid. The extent of turbidity is proportional to the mole fraction ol DMSO in the mixtures. The aim of the study was to find out to what extent do density and orientation fluctuations in refractive index contribute to the turbidity. Methods. Polarized light scattering measurements were conducted on rat lenses incubated in different DMSO-water media as a function of scattering angle. Light microscopy and scanning electron microscopy (SEM) probed the morphology of the lenses in different media. Results. While the parallel component of the scattered light intensity is directly proportional to the DMSO concentration, the perpendicular component exhibits a maximum around 0.25 DMSO mole fraction. The light scattering index, I₊/I., depicting the involvement of optical anisotropy fluctuations in cataractogenesis, also exhibits a maximum at 0.25 DMSO mole ratio. Microscopic examination shows maximum damage, in terms of fiber cell swelling, lake formation and disintegration of epithelium al 0.25 mole ratio of DMSO. SEM observation showed that at high DMSO concentrations, especially at 0.25 mole fraction, large part of the crystallins has disappeared and/or coalesced around the cytoskeletal bodies. Conclusions. The change in the organization of the components within the fiber cells disturbs the balance between intrinsic birefringence and form birefringence necessary for transparency. Thus the DMSO cataract can be described as a good model for the involvement of optical anisotropy fluctuations in opacification.