Er:YAG laser system generating a radiation in a free-running, long-pulse mode regime with an output energy up to 610 mJ and a wavelength in a mid-infrared region (2.94 micrometer) was used for ophthalmic micro-surgery. As a delivery system a cyclic olefin polymer-coated silver hollow glass waveguide was used. The delivery system was ended either by a focusing optics (CaF₂ lens) or by a special sapphire tip, for a non-contact and contact treatment, respectively. The corneal ablation and perforation of a sclera tissue were examined for the energies from 5 mJ up to 280 mJ and from 1 to 10 pulses in the case of non-contact and contact preparation. The threshold energy for the sclera ablation was measured for the non- contact procedure to be 122 mJ (24.3 J/cm²) in the case when 1 pulse was used. For the contact preparation this threshold energy was 270 J (34.4 J/cm²) for 5 pulses used. The iris contact ablation threshold energy was measured to be 10 mJ (1.3 J/cm²) for 1 pulse. The results show the usability of the 2.94 micrometer radiation in the ophthalmic surgery.

Date Published: 7 June 2000
PDF: 6 pages
Proc. SPIE 3908, Ophthalmic Technologies X, (7 June 2000); doi: 10.1117/12.387537

Published in SPIE Proceedings Vol. 3908:
Ophthalmic Technologies X
Pascal O. Rol; Karen Margaret Joos M.D.; Fabrice Manns, Editor(s)