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New Instrument
May 2002

Effects of the Pulsed Electron Avalanche Knife on Retinal Tissue

Author Affiliations

From the Department of Ophthalmology, School of Medicine (Drs Palanker, Marmor, Branco, Sanislo, and Blumenkranz and Messrs Huie and Miller) and W. W. Hansen Experimental Physics Laboratory (Drs Palanker and Vankov), Stanford University, Stanford, Calif. Stanford University is the owner of a patent covering the use of the electric plasma-mediated cutter. Should the Stanford University receive royalties or other financial remuneration in the future related to the patent, Dr Palanker may receive a share in accordance with the Stanford University Institutional Patent Policy and Procedures, which include royalty-sharing provisions. Drs Palanker and Blumenkrantz are consultants to Carl Zeiss, Inc, Jena, Germany.

Arch Ophthalmol. 2002;120(5):636-640. doi:10.1001/archopht.120.5.636

Objectives  To evaluate the precision of retinal tissue dissection by the pulsed electron avalanche knife (PEAK) and to assess possible toxic effects from this device.

Methods  To demonstrate precision of cutting, bovine retina (in vitro) and rabbit retina (in vivo) were incised with the PEAK. Samples were examined by scanning electron microscopy and histologic examination (light microscopy). To evaluate possible toxic effects in rabbit eyes, 30 000 pulses were delivered into the vitreous 1 cm above the retina. Histologic examinations and electroretinography were performed at intervals up to 1 month after exposure.

Results  Cuts in postmortem bovine retina showed extremely sharp edges with no signs of thermal damage. Full-thickness cuts in living attached rabbit retina were similarly sharp and were typically less than 100 µm wide. No signs of retinal toxic effects were detected by histologic examination or electroretinography.

Conclusions  The PEAK is capable of precise cutting through retinal tissue, and there are no demonstrable retinal toxic effects from its use. The precision and tractionless nature of PEAK cutting offers advantages over mechanical tools and laser-based instrumentation. We believe this new device will prove useful in a variety of vitreoretinal surgical applications.

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