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Proceedings Paper

Improved safety of retinal photocoagulation with a shaped beam and modulated pulse
Author(s): Christopher Sramek; Jefferson Brown; Yannis M. Paulus; Hiroyuki Nomoto; Daniel Palanker
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Paper Abstract

Shorter pulse durations help confine thermal damage during retinal photocoagulation, decrease treatment time and minimize pain. However, safe therapeutic window (the ratio of threshold powers for rupture and mild coagulation) decreases with shorter exposures. A ring-shaped beam enables safer photocoagulation than conventional beams by reducing the maximum temperature in the center of the spot. Similarly, a temporal pulse modulation decreasing its power over time improves safety by maintaining constant temperature for a significant portion of the pulse. Optimization of the beam and pulse shapes was performed using a computational model. In vivo experiments were performed to verify the predicted improvement. With each of these approaches, the pulse duration can be decreased by a factor of two, from 20 ms down to 10 ms while maintaining the same therapeutic window.

Paper Details

Date Published: 2 March 2010
PDF: 10 pages
Proc. SPIE 7550, Ophthalmic Technologies XX, 75500V (2 March 2010); doi: 10.1117/12.841079
Show Author Affiliations
Christopher Sramek, Hansen Experimental Physics Lab., Stanford Univ. (United States)
Jefferson Brown, Hansen Experimental Physics Lab., Stanford Univ. (United States)
Yannis M. Paulus, Stanford Univ. (United States)
Hiroyuki Nomoto, Stanford Univ. (United States)
Daniel Palanker, Hansen Experimental Physics Lab., Stanford Univ. (United States)
Stanford Univ. (United States)

Published in SPIE Proceedings Vol. 7550:
Ophthalmic Technologies XX
Fabrice Manns; Per G. Söderberg; Arthur Ho, Editor(s)

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