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Corneal electrodes useful for clinical electroretinography require topical anesthesia, interfere with vision, can abrade, and are not well accepted by most children and many adults. A low mass conductive thread, corneal (DTL) electrode is described and comparatively tested against the Burian-Allen electrode. The DTL electrode was found to have few of the(More)
The visual acuities (i.e., visual thresholds for pattern detection) of four dogs under neuromuscular block were measured using visually evoked cortical potentials (VECP) and/or pattern-evoked retinal potentials (PERR). Stimuli were phase-reversing square-wave gratings with a mean luminance of 86 cd/m2 and 70% contrast. The mean of the VECP thresholds of two(More)
Chronically implanted intraocular electrodes were used to stimulate visual cortical responses to current passage through the retina. Electrical current threshold for the light-adapted cat retina lies in the region of 30 to 100 X 10(-6) amps. for the conditions used. Dark adaptation caused a large threshold increase. Retinal excitability also decreased when(More)
Hereditary blindness in Rhode Island Red chickens was analyzed at various post-hatching stages by light microscopy and electrophysiological recordings. At the time of hatching the retina of affected chicks appeared morphologically normal and identical to that of control, non-affected chicks. Whereas the electroretinographic (ERG) response to light stimulus(More)
PURPOSE The goal of our study was the evaluation of a practical method for the recording of flash electroretinograms (ERGs) in sedated, standing horses with the DTL microfiber electrode. METHODS The horses were sedated intravenously with detomidine hydrochloride (0.015 mg/kg). The pupil was dilated and the auriculopalpebral nerve was blocked. The ERGs(More)
The late positive potential of the mammalian electroretinogram has been called the 'PI' or the 'c-wave' potential. It is unusual among retinal potentials because its peak implicit time increases in response to increasing stimulus intensity and because it cannot be demonstrated consistently in small samples of normal humans or normal dogs. We recorded(More)
PURPOSE The authors identify any diurnal intraocular pressure (IOP) variation in healthy Cayo Santiago macaques, as well as Cayo Santiago macaques with normotensive and hypertensive primary open-angle glaucoma (POAG), to further evaluate their potential value as a model for human POAG. METHODS Twenty-four monkeys (eight animals each of the healthy(More)
PURPOSE To compare the effect of exposure time from a blue(460 nm) light emitting diode(LED) on the morphology of the outer retina and determine conditions where damage occurs. MATERIALS AND METHODS Young adult rhesus monkeys were anesthetized, and received blue LED exposure from a modified slit-lamp. A 3 mm beam of 0.85 mW was imaged onto the retina(More)
Several tests of visual function were applied to an abstaining user (10 years or more) group and a nonuser group carefully preselected to be free of clinical signs of eye disease. The groups were matched on several criteria. The results show that all findings from both groups are within established limits of normalcy. Small differences and trends were found(More)
Fifty-four patients with a unilateral pigmented choroidal lesion were studied with electrooculography (EOG). Eighteen of 21 patients with histologically proven (13) or presumed (8) malignant tumors of the choroid had light peak-dark trough ratios (L/D) less than or equal to 150. Seventeen of 21 patients in the malignant group had an interocular L/D(More)