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Biomedical subjects

D J Lund

Publications and source records attributed to D J Lund.

10 recordsLinked to original sources
PubMed1989

Near infrared laser ocular bioeffects.

Thresholds for laser chorioretinal injury in the red end of the visible spectrum and the near-infrared (IR-A) spectral regions are presented. An unpredicted wavelength dependence of the injury threshold for single Q-switched pulses is demonstrated. Four lasers were used to determine thresholds at 40 wavelengths between 532 nm and 1064 nm: a ruby laser, a neodymium:YAG-pumped dye laser, an erbium:YLF laser and an alexandrite laser. Despite many careful and repeated efforts to determine a cause for the variation due to possible variations in the lasers or other aspects of the experimental technique and due to biological absorption properties of the eye, there is no complete or obvious explanation for the significant variations of threshold with small changes in wavelength. The implications of these findings for laser safety standards are presented.

Animals↗
PubMed1983

Urokinase-treatment of fresh laser irradiation-induced vitreous hemorrhage.

Using a ruby laser, we induced vitreous hemorrhage in each eye of 12 rabbits. On the following day either 25,000 Ploug units of urokinase or saline were injected into the eyes of each rabbit. Urokinase did not accelerate the absorption of blood from the vitreous but prevented the development of severe vitreous fibrosis which replaced the hemorrhage in seven of the control eyes.

Animals↗
PubMed1982

Grating visual evoked cortical potentials in the evaluation of laser bioeffects: instrumentation.

A system was designed to permit simultaneous viewing of the ocular fundus of the rhesus monkey (Macaca mulatta), the accurate placement of laser radiation on the retina, and the stimulation of the site to produce a grating visual evoked cortical potential (VECP). A fundus camera was modified to incorporate a grating whose image was projected onto the retina at specific locations. The evoked potential could thus be obtained for any rate of alternation before, during, and after the exposure of the fovea to any one of many laser sources. An example is shown of the use of this system to monitor the grating VECP before and after exposure of the animal's fundus to a 900 nm gallium arsenide laser source for 60 sec. In this case, changes were observed in the variability of the latency of components of the VECP when compared to the prelaser exposure potentials.

Animals↗
PubMed1977

Spectrophotometry of the canine bladder.

Canine bladders were subjected to spectrophotometric analysis in order to choose a laser for experimental endoscopic use. Percentages of transmission and reflection were obtained; these allowed derivation of an absorption curve throughout the wavelength range of water transparency. We conclude that the argon laser was the most appropriate system available at the present time.

Animals↗