RESUMO
Objective To study the optical imaging quality of multifocal intraocular lens (IOL) following Nd∶YAG laser damage.Methods Three hydrophobic acrylate discs used to make multifocal IOL were placed in line,and the Nd∶YAG laser was used to emit the posterior surface,mid-plane and anterior surface of the discs by gradually increasing the emitting energy to determine the damaged threshold energy of various planes.Eight multifocal IOLs were divided into 2 groups.IOL damage models were established by emitting 12 points along 12 clocks on circle of 3.0 mm in diameter in the group 1 (IOLs NO.1,2,3,4) and 6 points with 1-clock interval on circle of 1.0 mm in diameter in the group 2 (IOLs NO.5,6,7,8) with Nd∶YAG laser.The modulation transfer function (MTF),line spread function (LSF) and United States air force (USAF) test target images of the IOLs were tested under the optical aperture at 2.0,3.0 and 4.5 mm.Results The damage thresholds of laser power were not significantly different among three hydrophobic acrylate discs (Fgroup =1.100,P =0.337),and the thresholds were significantly different among different planes in the discs (Fposition =195.279,P=0.000),with the highest damage threshold in the anterior surface and the lowest damage threshold in the mid-plane of the discs(all at P＜0.01).The shifts of far focus and near focus MTF curves,LSF curves and USAF target images of the IOLs under the 2.0,3.0 and 4.5 mm optical aperture after laser damage were in coincidence with those before laser damage both in group 1 and group 2.The glare phenomenon of the USAF target image was observed at near focus under the 4.5 mm optical aperture both before and after laser damage.Conclusions Multifocal IOL is vulnerable to injury when the laser beam focuses on the midplane,and the anterior surface of IOL can tolerate certain degree of damage.In standard model eye,the MTF curves,LSF curves and USAF target images of multifocal IOL was not impacted by laser induced spots injuries under different pupil diameters.
RESUMO
<p><b>OBJECTIVE</b>To establish a HPLC-ELSD method for simultaneous determination of trillin and desgalactotigonin contents in Solanum lyratum.</p><p><b>METHOD</b>A Diamonsil C18 column (4.6 mm x 250 mm, 5 microm) was adopted, with the mobile phase consisting of acetonitrile-10 mmol x L(-1) ammonium acetate (52: 48). The temperature was 25 degrees C, the flow rate was set at 0.6 mL x min(-1), and the sample size is 20 microL. The temperature of drift tubes and gas flow rate of the detector were set at 95 degrees C and 2.3 L x min(-1), respectively.</p><p><b>RESULT</b>With in the linear ranges of 20-200 mg x L(-1) and 10-100 mg x L(-1), trillin and desgalactotigonin show a good linear relationship. The average recovery was 99.4% (RSD 0.90%) for trillin and 100.3% (RSD 1.1%) for desgalactotigonin.</p><p><b>CONCLUSION</b>The method is so accurate and easily reproducible that it is suitable for the quality control of S. lyratum medicinal materials.</p>