Williams Geraint P, George Benjamin L, Wong Yoke R, Yam Gary H F, Ang Marcus, Tay Shian C, Mehta Jodhbir S
Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore.
Corneal and External Eye Disease Service, Singapore National Eye Centre, Singapore, Singapore.
Invest Ophthalmol Vis Sci. 2017 Sep 1;58(11):4490-4498. doi: 10.1167/iovs.17-22227.
To determine the effects of the Ziemer LDV Z8 liquid interface femtosecond laser platform during capsulotomy under different energy settings in the presence of corneal edema.
Cadaveric porcine eyes (n = 36) employed at less than 6 and greater than 24 post enucleation hours to simulate clear/edematous corneas, underwent capsulotomy with the Ziemer LDV Z8 femtosecond laser (5-mm diameter, energy 90%, 130%, or 150%). Lens capsules were removed for evaluation by scanning electron microscopy and rupture strengths determined by the single column universal testing system. Following ethical approval, 23 patients had lens capsules removed during routine cataract surgery following manual or Z8 capsulotomy and subjected to TUNEL assay.
There was no difference in edge morphology or rupture strength (120, 113, and 118 mN at increasing energy, P = 0.42) in the clear cornea. Only 50% of capsulotomies succeeded at 90% energy in an edematous cornea, improving with increased energy (75% completion at 130%, 100% at 150%). Rupture strength in edematous corneas was not significantly different at 112, 133, and 114 mN for 90%, 130%, and 150%, respectively (P = 0.3). In human samples, increased TUNEL-positive cells were seen at 130% energy, but not at 150% (0.0 manual vs. 0.2 [90%] vs. 2.1 [130%] vs. 0.6 [150%], P < 0.05).
Because of the low energy delivered by a femtosecond nanojoule platform, even incremental increases in energy appeared to have minimal effect on lens capsule morphology and strength and negligible influence on cell death. Furthermore, increasing energy appeared to enhance consistency and the ability to complete a capsulotomy in an edematous cornea.
确定在角膜水肿情况下，Ziemer LDV Z8液体界面飞秒激光平台在不同能量设置下行晶状体囊切开术的效果。
采用摘除眼球后6小时内及24小时后的猪尸体眼（n = 36）来模拟透明/水肿角膜，使用Ziemer LDV Z8飞秒激光行晶状体囊切开术（直径5毫米，能量分别为90%、130%或150%）。取出晶状体囊膜，通过扫描电子显微镜进行评估，并使用单柱通用测试系统测定破裂强度。经伦理批准后，23例患者在常规白内障手术中，于手动或Z8晶状体囊切开术后取出晶状体囊膜，并进行TUNEL检测。
在透明角膜中，边缘形态或破裂强度（能量增加时分别为120、113和118毫牛，P = 0.42）无差异。在水肿角膜中，90%能量时只有50%的晶状体囊切开术成功，随着能量增加成功率提高（130%时完成率为75%，150%时为100%）。水肿角膜中，90%、130%和150%能量时的破裂强度分别为112、133和114毫牛，差异无统计学意义（P = 0.3）。在人体样本中，130%能量时可见TUNEL阳性细胞增加，但150%能量时未见（手动为0.0，90%为0.2，130%为2.1，150%为0.6，P < 0.05）。
由于飞秒纳焦平台传递的能量较低，即使能量逐步增加，对晶状体囊膜形态和强度的影响似乎也极小，对细胞死亡的影响可忽略不计。此外，增加能量似乎可提高水肿角膜中晶状体囊切开术的一致性和完成能力。
