Element concentrations and cataract: an experimental animal model

The determination of inorganic ions in cataractous human lenses has been th e subject of several investigations; nevertheless, few studies have been co ncerned with trace element contents in lenses, and data are sometimes contr adictory. An animal experimental model of induced cataract is here proposed with the aim of evaluating the changes of Ca, Na, K, Cu and Zn concentrati ons. The cataract was produced by an Nd: YAG Laser treatment of the right e ye of sexteen male rabbits. The determination of the elements was performed by atomic absorption spectrometry (both flame and flameless methods) after an acid digestion of samples. Compared with the results obtained in left l enses used as a control (Ca 14.4 +/-5.7 mg/kg d.w.; Na 1.3 +/-0.5 g/kg d.w. ; K 9.9 +/-1.1 g/kg d.w.; Cu 0.24 +/-0.09 mg/kg d.w.; Zn 24.8 +/-2.3 mg/kg d.w.), the mean concentration values of opaque lenses showed some significa nt changes for Ca, Na, and Cu (Ca 123.7 +/- 106.6 mg/kg d.w.; Na 4.5 +/-4.3 g/kg d.w; CU 0.43 +/-0.21 mg/kg d.w.). Potassium showed a tendency to decr ease, and zinc to increase. Positive correlations were found between calciu m and sodium both in controls (r= 0.73, p <0.001) and in treated lenses (r= 0.87, p < 0.0001). An inverse correlation between Ca and K confirmed the t endency of potassium to decrease.