[Spatial confinement of intraocular picoseconds-photodisruption effects]

Laser photodisruption is a routinely performed clinical procedure in intraocular microsurgery of post-cataract membranes, anterior synechies and iridectomies. Damage ranges of several millimeters in diameter, however, limit the use of nanosecond photodisruption close to delicate structures, e.g., in the posterior vitreous. Multiple ps-laser pulses of about 100 microJ pulse energy were used to produce disruptive effects in the anterior lens capsule in rabbit eyes in vivo. Ophthalmoscopical and morphological investigations of these effects were compared with those of minimal ns-disruptions. The direct tissue separation effects as well as the collateral damage zones are about one order of magnitude smaller if ps-laser pulses are used. Minimal sizes of disruptive effects are about 50 microns to 150 microns and 500 microns to 1000 microns for ps- and ns-pulses, respectively. The substantial improvement of spatial confinement of ps-photodisruption enables increased precision of intraocular laser microsurgery and opens up new areas of clinical application in structures like the cornea, anterior chamber angle, and crystalline lens.