显微白内障手术光性视网膜损伤的F—ERG观察

目的　观察现代囊外白内障术中显微镜光照对视网膜功能的影响。方法　应用国际标准化视网膜电流图(F-ERG)记录45例45眼白内障术前及(白内障囊外摘出)术后1moF-ERG最大反应(MCR)(a、b波振幅)。按(WHO)晶状体混浊度分级采用不同术式，A组PHACO术、B组ECCE术。A组术中实际曝光于显微镜下25～40min(31.4min±4.1min)，中度光强；B组50～75min(59.8min±8.7min)，中高度光强。比较2组中使用不同显微镜光照(时间和光强)对ERG反应的影响，评价其对视网膜功能的损害。结果　白内障术后1moF-ERGa、b波振幅较术前均有不同程度的增大(0.01＜P＜0.05)；A组术后F-ERG振幅较术前明显增大(P＜0.01)；B组较术前增大，但无显著性差异(0.01＜P＜0.05)。结论　白内障术后ERG反应有不同程度的增强，提示晶状体混浊可减弱ERG反应；显微镜光照下手术时间越长、光照越强，术后1moF-ERG反应增幅越小，提示持续显微镜下手术可致视网膜光毒性损伤。

Observation of F-ERG onthe light-induced retinal damage during microscopic cataract surgery

Objective To observe the influence of microscopic lightillumination on the retinal function during the cataract extraction surgery.Methods Applying the standardized F-ERG recording technique to measure the amplitude of a-wave and b-wave of the maximal combined response(MCR) of F-ERG in 45 cases(45 eyes) of cataract patients pre-operation and post-operation. According to different lens opacity (as WHO classification) different operative methods (group A-PHACO, group B-ECCE)are used. The exposuring time under microscope light in group A was 25～40min(mean 31.4min±4.1min), the light intensity was moderate, whereas the exposuring time in group B was 50～75min(mean 59.8min±8.7min), the light intensity was moderate to high. Comparing different microscopic light illumination(time and intensity)with ERG response to evaluate its damage to the retinal function.Results The amplitudes of a-wave and b-wave one month post-operation are larger than those of pre-operation;The amplitude of F-ERG in group A post-operation is significantly larger than that of pre-operation (P＜0.01);In group B it was somewhat larger than it was post-operation(0.01＜P＜0.05).Conclusions ERG response of cataract eyes will be increased in various degrees post-operation, which suggests that lens opacity can reduce the response; The longer the operation and the exposure time spent under microscope light, the lower the F-ERG response gets 1 month post-operation. We can come to the conclusion that continuous surgery under microscopic light illumination can induce the retinal light damage.