Stepanov A V, Babizhaev M A, Ivanov A N, Aĭtmagambetov M T, Deev A I
Vestn Oftalmol. 1990 Jan-Feb;106(1):31-5.
Structural changes in the lens and vitreous body exposed to short-pulse Nd:YAG Q-switching laser were under study. The laser was focussed in the lens nucleus or vitreous center plane. A pulse energy was 7.1-9.3 mJ, with a total of 75-100 pulses. Cataract development was induced via the formation of cavities with the guidance spot focal plane localized in the lens nucleus plane. When the focus was in the vitreous body and the laser operated in a similar energy mode, great numbers of small cavities rapidly formed, this evidencing a shock wave propagation. Specific and structural conformational changes in the lens and vitreous protein molecules were detected by nitrate quenching of the triptophane amino acid residue fluorescence. Laser exposure was found to reduce triptophanile availability for nitrates, this evidencing protein complexes aggregation (collapse); besides, laser exposure essentially increased the amino acid residue quenching constants, which fact pointed to a decreased density of the vitreous collagen and lens crystalline negative charges (increased hydratation). These findings permit a conclusion that the shifts connected with injury to the vitreous body, with macular edema, or with detachment of the retina after exposure to Nd:YAG laser may be due to collapse of the vitreous gel liquified components.
对暴露于短脉冲钕钇铝石榴石调Q激光下的晶状体和玻璃体的结构变化进行了研究。激光聚焦在晶状体核或玻璃体中心平面。脉冲能量为7.1 - 9.3 mJ，共75 - 100个脉冲。通过在晶状体核平面定位引导光斑焦平面形成空洞来诱导白内障发展。当焦点位于玻璃体且激光以类似能量模式运行时，大量小空洞迅速形成，这证明了冲击波的传播。通过色氨酸氨基酸残基荧光的硝酸盐猝灭检测晶状体和玻璃体蛋白质分子的特定结构构象变化。发现激光照射会降低色氨酸对硝酸盐的可用性，这证明蛋白质复合物聚集（塌陷）；此外，激光照射本质上增加了氨基酸残基的猝灭常数，这一事实表明玻璃体胶原蛋白和晶状体晶体负电荷密度降低（水合作用增加）。这些发现可以得出结论，暴露于钕钇铝石榴石激光后与玻璃体损伤、黄斑水肿或视网膜脱离相关的变化可能是由于玻璃体凝胶液化成分的塌陷所致。
