New semiconductor laser for vitreoretinal surgery.
OBJECTIVE
We investigated the potential application in vitreoretinal surgery of a CW diode laser with cutting capabilities.


METHODS
A semiconductor CW laser emitting 300 mW optical power at 1.94 microns wavelength was used to perform retinotomies and membrane cutting on rabbit eyes. The device was integrated into a dedicated controller. The laser radiation was delivered through a low attenuation fused silica optical fiber of 200 microns core size, terminating into a 20-gauge endo-ocular handpiece. Histological aspects of threshold lesions obtained on the rabbits' chorioretina were evaluated by light microscopy.


RESULTS
We obtained circular and linear full-thickness retinotomies with contact and noncontact procedures using energy of 120 mJ (240 mW x 0.5 s). Using a non-contact procedure, a larger peripheral coagulation halo around the retinotomies was observed, as compared to the contact method. The adjacent zone of thermal damage ranged from 50 to 200 microns. Lower efficacy was obtained on experimentally induced epiretinal membranes, where only superficial ablation was achieved.


CONCLUSIONS
The CW 2 microns diode laser will have a promising future in vitreoretinal surgery when a higher output irradiance is available.
Department of Ophthalmology and Visual Sciences, Scientific Institute H.S. Raffaele, University of Milan, Italy.
C
C
Azzolini
P G
PG
Gobbi
R
R
Brancato
G
G
Trabucchi
M
M
Codenotti
D000818:Animals; D006358:Hot Temperature; D053685:Laser Therapy / Q000295:instrumentation*; D007834:Lasers; D055585:Physical Phenomena; D010825:Physics; D011817:Rabbits; D012160:Retina / Q000033:anatomy & histology / Q000601:surgery*