[Excimer laser technique--a revolution in refractive surgery?].
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to B Tengroth.
Explore the source record for details and available documents.
We report on a 19-year-old male patient who was operated on for an orbital tumor close to the trochlea. The microscopical examination showed a cartilaginous tumor classified as differentiation grade II. Because of the close topographic location to the trochlea the tumor is characterized as a chondroma. Its rare location does not give us any further information concerning the final dignity. Benign cartilaginous tumors of the orbital trochlea region are extremely uncommon.
Explore the source record for details and available documents.
The effects of an adapting flash of different colors on human vision were investigated with various flashes and target luminances. The readaptation time (RAT) was measured using optokinetic nystagmus elicited by a projected moving striped pattern in a hemisphere. The RATs were recorded from 26 subjects with a multichannel pen recorder. Two target luminances (1.1 X 10(-5) cd/m2 and 2.6 X 10(-5) cd/m2) and 12 flash wavelengths (449 nm, 456 nm, 468 nm, 477 nm, 498 nm, 502 nm, 520 nm, 565 nm, 580 nm, 591 nm, 622 nm, and 703 nm) were used. A spectral RAT curve was obtained, which showed that the chromatic response of RAT follows this order: green greater than blue greater than yellow greater than red. A larger influence of the variation of the target luminance on the RAT was demonstrated at shorter wavelengths. The results also showed that the energy density of the flash has a larger variation with the RAT in blue and green than in red.
Explore the source record for details and available documents.
The readaptation time (RAT) is the interval during which a person exposed to a bright intense light flash cannot perceive a given target. In this study the target used was an optokinetic pattern and the elicited nystagmus (OKN) was registered with electrooculography (EOG), thus giving an objective registration of RAT. Oxazepam in therapeutic doses was given to five healthy subjects and the RAT and serum concentrations of the drug were registered simultaneously at different time intervals. An almost parallel increase of RAT and serum concentration of oxazepam was recorded. This suggests that RAT reflects the depressant effect on the CNS of this drug and it may be used as an objective method of following the clinical effect of a depressant drug as a function of time after intake.
The effect of alcohol intake on readaptation time (RAT) after photo stress is studied. Ten healthy subjects were given 0.72 g alcohol per kg body weight to be consumed within 20 min. The tests were made during a total period of 11-12 h. The findings demonstrate that moderate blood alcohol concentrations induce definite changes in RAT. An average RAT-prolongation of 60-70% was seen during the acute phase of intoxication. RAT-prolongation ended before the blood alcohol concentration had reached zero, but did not have the same downward slope. Following a period of reduction, a new prolongation of RAT was observed. The lack of congruence between the RAT-curve and the blood alcohol curve in the acute phase of intoxication and the post-alcohol increase are discussed. It is concluded that the alcohol-induced RAT-changes probably are CNS-effects and that the equipment used constitutes a sensitive method of estimating these effects.
The 60Co applicator for treatment of retinoblastoma, described in 1963, has the advantage of exact local positioning. It is suitable in cases with solitary small tumours. The complications and the results of treatment in 20 patients followed up for at least 2 years are reported and discussed.
Two types of electric welding, welding with gas-shielded arcs and welding with coated electrodes, are considered in this paper. The possible radiation injuries to the eye are described, and the measures for protection discussed.
Explore the source record for details and available documents.
Optokinetic nystagmus (OKN) is used to study the eye's ReAdaptation Time (RAT) after a brief exposure to a light flash. The effects on RAT of breathing different concentrations of O2 are examined. Significant changes in RAT have been registered, showing that inhalation of 100% O2 as compared with room air, results in a shortened RAT (i.e. improvement), while inhalation of 9% O2 leads to an increased RAT (i.e. impairment). The physiology of RAT and the possible mechanisms behind the changes caused by different O2 concentrations are discussed. The findings of this group are compared with those of other studies.
Radiographic exophthalmometry is based on the simultaneous exposure of a radiograph and a photograph. The fixed reference point for both eyes is the tuberculum sellae, which is a midline structure. Eye position is correlated with skull size and race to provide a sensitive detection of exophthalmos. A statistically significant difference in the position of the eyes in US black and white people has been found to exist. No difference in the position of left or right eyes has been found in either US black or white people.
A previously described photoradiographic camera used to localize intraocular or intraorbital foreign bodies has been modified to a more versatile unit. One photograph and one radiograph are taken simultaneously, and the pictures are combined, whereby the eye appears as its own indicator on the radiophotograph. More than 50 foreign bodies have been successfully localized with the camera which is easy to handle and can be used in any x-ray film room where an overhead tube is available.