Laser-Induced Bulk Damage of Various Types of Silica Glasses at 266 nm

et al. 2008

SPIE Proceedings

We report the use of an ultraviolet (UV) laser and optical fibre arrangement capable of precise and controllable tissue ablation. The 5 th (213nm) and 4 th (266nm) harmonics of a Nd:YAG laser were launched into optical fibres using a hollow glass taper to concentrate the beam. Standard and modified silica/silica optical fibres were used, all commercially available. The available energy and fluence, as a function of optical fibre length, were evaluated and maximised. Single 5ns pulses were used to ablate both fresh porcine retina and in vivo rat trabecular meshwork. Fluences of 0.4 to 4.0 J/cm 2 of 266nm and 0.2 to 1.0 J/cm 2 of 213nm were used respectively. Thus demonstrating the potential use of this system for intraocular surgical applications.

Section: Syetem Performancementioning

confidence: 71%

Tissue ablation via optical fibre delivery of UV laser radiation

et al. 2008

SPIE Proceedings

Laser-fiber system for ablation of intraocular tissue using the fourth harmonic of a pulsed Nd:YAG laser

Cringle

et al. 2007

Appl. Opt.

We report on a method for delivering high fluence pulsed 266 nm laser radiation to the target tissue via an optical fiber. The fourth harmonic of a Nd:YAG laser was concentrated using a hollow glass taper and launched into an optical fiber. Fluences of up to 2 J/cm(2) were routinely output at the tapered optical fiber tip. The maximum fluence generated before failure of the optical fiber was between 3.5 and 8 J/cm(2). Ablation of ocular tissue was demonstrated using fluences of 1.0 and 0.4 J/cm(2). The delivery system has the potential for use in intraocular surgical procedures.

Development of a fiber-optic laser delivery system capable of delivering 213 and 266 nm pulsed Nd:YAG laser radiation for tissue ablation in a fluid environment

et al. 2011

Appl. Opt.

Ultraviolet (UV) lasers have the capability to precisely remove tissue via ablation; however, due to strong absorption of the applicable portion the UV spectrum, their surgical use is currently limited to extraocular applications at the air/tissue boundary. Here we report the development and characterization of a fiber-optic laser delivery system capable of outputting high-fluence UV laser pulses to internal tissue surfaces. The system has been developed with a view to intraocular surgical applications and has been demonstrated to ablate ocular tissue at the fluid/tissue boundary. The fifth (213 nm) and fourth(266 nm) harmonics of a Nd:YAG laser were launched into optical fibers using a hollow glass taper to concentrate the beam. Standard and modified silica/silica optical fibers were used, all commercially available. The available energy and fluence as a function of optical fiber length was evaluated and maximized. The maximum fluence available to ablate tissue was affected by the wavelength dependence of the fiber transmission; this maximum fluence was greater for 266 nm pulses (8.4 J/cm2) than for 213 nm pulses (1.4 J/cm2). The type of silica/silica optical fiber used did not affect the transmission efficiency of 266 nm pulses, but transmission of 213 nm pulses was significantly greater through modified silica/silica optical fiber. The optical fiber transmission efficiency of 213 nm pulses decreased as a function of number of pulses transmitted, whereas the transmission efficiency of 266 nm radiation was unchanged. Single pulses have been used to ablate fresh porcine ocular tissue. In summary, we report a method for delivering the fifth (213 nm) and fourth (266 nm) harmonics of a Nd:YAG laser to the surface of immersed tissue, the reliability and stability of the system has been characterized, and proof of concept via tissue ablation of porcine ocular tissue demonstrates the potential for the intraocular surgical application of this technique.