Lubatschowski H, Schumacher S, Wegener A, Fromm M, Oberheide U, Hoffmann H, Gerten G
Biomedical Optics, LZH, Hannover.
Klin Monbl Augenheilkd. 2009 Dec;226(12):984-90. doi: 10.1055/s-0028-1109941. Epub 2009 Dec 15.
Based on the Helmholtz theory for accommodation, increasing sclerosis of the lens nucleus and cortex is the main cause for the development of presbyopia. Existing therapies, however, do not reverse the stiffness of the crystalline lens and thus do not regain real accommodation ability. A new approach to restore the flexibility of the lens has been realised by utilising the non-linear interaction of ultrafast laser pulses with transparent tissue, the so-called photodisruption. This process has been used to create micro-incisions which act as gliding planes inside the crystalline lens without opening the eye globe. This treatment method, known as fs-lentotomy, enables regeneration of real dynamic accommodation. For the first time, 3D structures for gliding planes were successfully generated in experiments with human donor lenses of different ages. An average increase in anterior-posterior lens thickness of 100 mum accompanied by a decrease of equatorial lens diameter was observed as a direct consequence of fs-lentotomy. This is attributed to the increased flexibility, as the force of the capsule bag moulds the lens tissue more spherically. Moreover, in vivo experiments on rabbit eye lenses did not induce an increasing opacification (cataract) over a six-month follow-up period. However, the incisions were still detectable using Scheimpflug imaging and histopathological techniques, although the visibility of the incisions was declining. Furthermore, no side effects were observed during the wound healing process and during a six-months follow-up period. Based on these findings fs-lentotomy might have the potential to become a procedure for the reversal of presbyopia.
根据亥姆霍兹调节理论，晶状体核和皮质的硬化加剧是老花眼形成的主要原因。然而，现有的治疗方法并不能逆转晶状体的硬度，因此无法恢复真正的调节能力。通过利用超快激光脉冲与透明组织的非线性相互作用，即所谓的光破裂，实现了一种恢复晶状体柔韧性的新方法。这一过程已被用于制造微切口，这些微切口在不打开眼球的情况下充当晶状体内部的滑动平面。这种治疗方法被称为飞秒激光晶状体切开术，能够实现真正动态调节的再生。在对不同年龄的人类供体晶状体进行的实验中，首次成功生成了用于滑动平面的三维结构。飞秒激光晶状体切开术的直接结果是观察到晶状体前后厚度平均增加100微米，同时晶状体赤道直径减小。这归因于柔韧性的增加，因为囊袋的力量使晶状体组织更呈球形。此外，对兔眼晶状体的体内实验在六个月的随访期内并未导致混浊增加（白内障）。然而，尽管切口的可见性在下降，但使用Scheimpflug成像和组织病理学技术仍可检测到切口。此外，在伤口愈合过程和六个月的随访期内未观察到任何副作用。基于这些发现，飞秒激光晶状体切开术可能有潜力成为一种逆转老花眼的手术方法。
