Krause M, Steeb D, Foth H J, Weindler J, Ruprecht K W
Department of Ophthalmology and Eye Hospital Homburg, University of Saarland, Germany.
Invest Ophthalmol Vis Sci. 1999 May;40(6):1025-32.
Using a noncontact erbium (Er):yttrium--aluminium--garnet (YAG) laser, ablation of vitreous was compared to distilled water in vitro.
The porcine vitreous body and distilled water were ablated in vitro at different pulse lengths and pulse energies. Selected pulse energies were 25, 35, 45, 75, and 100 mJ (pulse rate: 1 Hz; laser beam diameter at the surface of the sample: 2 mm). Pulse lengths were at 140 +/- 3 microsec, 190 +/- 4 microsec, and 240 +/- 5 microsec. The loss of weight in vitreous tissue and distilled water was measured using precision scales and corrected for evaporation, respectively. The Mann-Whitney U test was used to assess the significance of differences in ablation rates of water and vitreous. P < 0.05 was considered statistically significant.
Reproducible and constant ablation rates were found in both vitreous and distilled water in each of 10 consecutive series of 50 laser pulses at constant laser parameters. Ablation rates per pulse (microg/microsec) of vitreous tissue were as follows: 3.0 microg to 45.8 microg (140 microsec), 10.4 microg to 53.8 microg (190 microsec), and 17.9 microg to 24.2 microg (240 microsec). The ablation rates exhibited a linear correlation with increasing pulse energies and also with decreasing pulse lengths. Considering the pulse lengths of 190 microsec and 240 microsec with all pulse energies tested, the ablation rates of distilled water were significantly higher (P < 0.05) than ablation of vitreous tissue. The ablation rates at a pulse length of 140 microsec were not significantly different. The differences per pulse were as follows: 0.5 microg to 2.1 microg (140 microsec), 1.9 microg to 6.0 microg (190 microsec), and 3.5 microg to 8.7 microg (240 microsec).
Vitreous ablation is possible using Er:YAG laser. The ablation characteristics of vitreous have proved to be similar but not equal to that of water.
使用非接触式铒（Er）：钇铝石榴石（YAG）激光，在体外比较玻璃体的消融与蒸馏水的消融情况。
在体外以不同的脉冲长度和脉冲能量对猪玻璃体和蒸馏水进行消融。选定的脉冲能量为25、35、45、75和100 mJ（脉冲频率：1 Hz；样品表面的激光束直径：2 mm）。脉冲长度为140±3微秒、190±4微秒和240±5微秒。分别使用精密天平测量玻璃体组织和蒸馏水中的重量损失，并对蒸发进行校正。采用曼-惠特尼U检验评估水和玻璃体消融率差异的显著性。P<0.05被认为具有统计学显著性。
在恒定激光参数下，对玻璃体和蒸馏水分别进行连续10组、每组50次激光脉冲的消融，均发现可重复且恒定的消融率。玻璃体组织的每脉冲消融率（微克/微秒）如下：3.0微克至45.8微克（140微秒）、10.4微克至53.8微克（190微秒）和17.9微克至24.2微克（240微秒）。消融率与增加的脉冲能量以及减小的脉冲长度呈线性相关。考虑到所有测试脉冲能量下190微秒和240微秒的脉冲长度，蒸馏水的消融率显著高于玻璃体组织的消融率（P<0.05）。140微秒脉冲长度时的消融率无显著差异。每脉冲差异如下：0.5微克至2.1微克（140微秒）、1.9微克至6.0微克（190微秒）和3.5微克至8.7微克（240微秒）。
使用Er:YAG激光可以进行玻璃体消融。已证明玻璃体的消融特性与水相似但不相同。
