Morphologic characteristics and chemical composition of Christmas tree cataract.

摘要: Purpose Christmas tree cataract consists of highly refractile multicolored "needles" crisscrossing the lens fibers deep cortex. The fact that colors vary according to angle incident light, and in retroillumination only a dim outline is seen, would suggest diffractive phenomenon. This study was performed unravel ultrastructure chemical composition needles. Methods Eight lenses from donor eyes four extracapsularly extracted with were investigated by scanning transmission electron microscopy. studied energy-dispersive x-ray microanalysis Raman microspectroscopy. Results Scanning microscope examination showed needles are smooth, rectangular, plate-like elements bordered membranes amorphous material running crisscross through lens. In specimens for microscopic examination, proved be largely dissolved, but remains regular spacings approximately 5 nm. Material identical spacing density found neighboring cells bound reticular membranous network originating fiber-limiting membranes. Energy-dispersive have high sulfur content pronounced S-S, CS-SC, C-S vibrations. cytoplasm adjacent meshwork had an elevated Ca++ content. Conclusions It concluded cystine most likely candidate probably formed as result age-related aberrant breakdown crystallins induced levels.