Objective: To study the characteristics of the lens turbidity after long-term exposure to low intensity 635nm laser. Methods: Cluster sampling method was adopted to select 812 employees in a laser leveler workshop in a city of Guangdong Province from January 2014 to December 2018. They were divided into the control group, diffuse reflection (DR) group and direct vision (DV) group for retrospective observation and analysis of lens turbidity. The laser irradiation intensity of each group was investigated, the position and shape of lens opacity were analyzed, and the influencing factors were statistically analyzed with the repeated measurement data of dichotomy. Results: The laser irradiance and radiant exposure of DV group were between 0.72×10(-4) and 9.92×10(-4) mW/cm(2) and between 2.61×10(-2) and 1.53 J/cm(2), respectively. The subjects were mainly diagnosed with lens turbidity lesion, especially for the DV group. Most of lesions occurred in the pole and periphery of the anterior cortex. The lesions exhibited multipoint patterns with greyish white color. The turbidity rates in DV group (before work and work for 1, 2, 3 years) were 0%, 1.99% (8/402) , 4.98% (20/402) and 6.72% (27/402) , respectively, in the order of observation points. The statistical analysis of single factor effect showed that the turbidity rate was higher in DV group and higher in the second year in the DV group (P<0.01) . Multi-factor analysis of the laser effect on the lens showed that the main effect between groups, between the observation point were statistically significant (P<0.05) , but no statistical significance in the interaction between group×observation points (P>0.05) . Conclusion: Lens turbidity lesion can be caused by long-term exposure to low intensity 635 nm laser, so the product safety classification should be strictly strengthened. It is necessary to strengthen the protection of laser photochemical damage in the production process.
目的： 研究长期反复接触低强度635 nm激光致眼晶状体混浊特征。 方法： 于2019年12月，采取整群抽样方法，选取2014年1月至2018年12月广东省某市生产激光水平仪车间812人作为研究对象，根据工作中接触激光情况分成对照组（不接触激光）、激光漫反射组和激光直视组进行晶状体损伤回顾性观察分析。调查各组岗位激光辐照强度，分析各组员工晶状体混浊部位、形态，应用二分类重复测量资料进行影响因素的统计分析。 结果： 激光直视组员工岗位检出激光辐照度为0.72×10(-4)~9.92×10(-4) mW/cm(2)，照射量为2.61×10(-2)~1.53 J/cm(2)。研究对象均有晶状体混浊病变，各组均随时间增加病变增多，以激光直视组员工最多；多发生于前皮质的前极部及周边，发病形态以点状为主。激光直视组晶状体混浊率按观测点顺序（岗前及第1、2、3年）分别为0%、1.99%（8/402）、4.98%（20/402）和6.72%（27/402）。单因素分析显示，激光直视组晶状体混浊率较高，激光直视组第2年起晶状体混浊率高（P<0.01）；多因素分析显示，激光对晶状体影响的组间、观测点主效应均有统计学意义（P<0.05），分组×观测点交互作用无统计学意义（P>0.05）。 结论： 长期反复直视635 nm激光可致眼晶状体混浊病变，需严格强化产品安全分类，生产过程中需加强激光光化学作用致损伤防护。.
Keywords: Laser level instrument; Lasers; Lens turbidity lesion; Radiation.