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April 1989

Corneal Ablation by Nanosecond, Picosecond, and Femtosecond Lasers at 532 and 625 nm

Author Affiliations

From the Laser Research Laboratory, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston (Mr Stern and Drs Puliafito and Dobi); and the Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge (Mr Schoenlein and Dr Fujimoto). Dr Birngruber is visiting from the H. Wacker Laboratory, Augenklinik der Universität München, Munich, Federal Republic of Germany.

Arch Ophthalmol. 1989;107(4):587-592. doi:10.1001/archopht.1989.01070010601038

• We produced corneal excisions with nanosecond (ns)-, picosecond-, and femtosecond (fs)-pulsed lasers at visible wavelengths. The threshold energy for ablation was proportional to the square root of the pulse duration and varied from 2.5 microjoules (μJ) at 100 fs to 500 μJ at 8 ns. Excisions made with picosecond and femtosecond lasers were ultrastructurally superior to those made with nanosecond lasers and, at pulse energies near threshold, showed almost as little tissue damage as excisions made with excimer lasers at 193 nm. We conclude that ultra-short-pulsed lasers at visible and near-infrared wavelengths are a possible alternative to excimer lasers for corneal surgery and might have advantages over conventional ophthalmic neodymium-YAG lasers for some intraocular applications.

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