Roider J, Brinkmann R, Wirbelauer C, Laqua H, Birngruber R
Department of Ophthalmology, University of Regensburg, Germany.
Arch Ophthalmol. 1999 Aug;117(8):1028-34. doi: 10.1001/archopht.117.8.1028.
To investigate whether photocoagulation of the retinal pigment epithelium is possible with sparing of the photoreceptors.
Mild laser effects of a neodymium:yttrium-lithium-fluoride (Nd:YLF) laser (527 nm) were applied to 17 patients. To establish the necessary energy, test exposures were performed to the lower macula (laser variables: 1.7 microseconds, 100 and 500 pulses applied in a train at 500 Hz, 20-130 microJ, 160 microm). Of 179 test lesions, 73 were followed up at various time intervals up to 1 year by performing microperimetry directly on top of the laser lesions.
All of the test lesions were at the threshold of retinal pigment epithelial disruption, and none of the laser effects were visible by ophthalmoscopy during photocoagulation; they were detectable only by fluorescein angiography. After exposure with 500 pulses, retinal defects were detected in up to 73% of the patients (100 microJ) after the first day. Most of these defects were no longer detectable after 3 months. After exposure with 100 pulses, no defects could be detected with 70 and 100 microJ after 1 day. The absence of microscotomas in the follow-up period suggests that retinal damage was minimal or, if it occurred, was functionally repaired.
By choosing proper energy and number of pulses, it is possible to produce retinal pigment epithelial effects with no subsequent retinal damage detectable by microperimetry.
研究在保留光感受器的情况下对视网膜色素上皮进行光凝是否可行。
对17例患者应用钕：钇锂氟化物（Nd:YLF）激光（527nm）产生轻微激光效应。为确定所需能量，对黄斑下部进行测试曝光（激光参数：1.7微秒，以500Hz频率连续施加100和500个脉冲，20 - 130微焦，160微米）。在179个测试光斑中，73个通过直接在激光光斑上方进行微视野检查，在长达1年的不同时间间隔进行随访。
所有测试光斑均处于视网膜色素上皮破坏阈值，光凝过程中通过检眼镜检查均未见激光效应；仅通过荧光素血管造影可检测到。在施加500个脉冲曝光后，高达73%的患者（100微焦）在第一天后检测到视网膜缺损。这些缺损大多数在3个月后不再可检测到。在施加100个脉冲曝光后，在1天后用70和100微焦未检测到缺损。随访期间无微暗点表明视网膜损伤最小，或者即使发生损伤，也在功能上得到了修复。
通过选择合适的能量和脉冲数，可以产生视网膜色素上皮效应，且后续通过微视野检查未检测到视网膜损伤。
