Iridotomy and capsulotomy on porcine eyes with ultrashort laser pulses in the picosecond regime

Abstract

The laser systems currently used in ophthalmology either have some pulse length dependent side effects or are very expensive due to their complexity. Therefore, a newly developed approach using picosecond laser sources is investigated. These lasers combine the advantages of the low price of currently used short-pulse laser sources with the cold material ablation possibilities of high-end femtosecond sources. The surgeries intended are laser iridotomy, capsulotomy/post-cataract treatment and selective laser-trabeculoplasty (SLT). They are demonstrated on post mortem porcine eyes. The result is a more precise, less frayed tissue ablation with picosecond pulses in comparison to nanosecond pulses. The pulse energy could be reduced to (50 20) µJ per pulse instead of 1mJ to 10mJ per pulse, which is currently applied. The study of shock waves and cavitation bubbles revealed a huge difference in pressure between picosecond pulses (0:25MPa at 50 µJ) and nanosecond pulses (37MPa at 5 mJ). Therefore, the risk of collateral damage leading to potential additional clinical patterns and adverse effects could be significantly reduced.

Ophthalmic surgeries on post mortem porcine eyes with picosecond ultrashort laser pulses

“…Moreover, a typical jet formation (3) can be seen left of the bubble. The laser was irradiated from the left ( 42 , 43 ).…”

“…Moreover, a typical jet formation (3) can be seen left of the bubble. The laser was irradiated from the left (42,43). The longer the pulse width and the higher the pulse energy, the higher the temperature change.…”

Passively Q-switched sub-100 ps Yb3+:YAG/Cr4+:YAG microchip laser: experimental results and numerical analysis

“…Experiments with 12 ps pulses of much lower energy (about 30 µJ to 50 µJ) at 1064 nm show promising results due to the lower energy and heat input. 1 Since such systems usually consist of a mode-locked oscillator and a regenerative amplifier, they are not suitable for the reasons already mentioned. An alternative approach is to use passively Q-switched microchip lasers.…”