Biomedical subjects

K Breidenbach

Publications and source records attributed to K Breidenbach.

4 recordsLinked to original sources

PubMed2003

[Testing central retinal function with multifocal electroretinography before and after photodynamic therapy].

BACKGROUND: Photodynamic therapy (PDT) is applied for certain forms of choroidal neovascular membrane (CNV). The aim of this study was to investigate the effect of PDT on central retinal function as assessed by multifocal electroretinography (ERG). METHODS: 24 patients (25 eyes) with CNV (>50% classic 12 eyes) or occult (9 eyes) in age related macular degeneration (AMD) and CNV with pathological myopia (4 eyes) were treated by PDT using Verteporfin((R)). Before and a median of 6 weeks after therapy, central retinal function was examined using multifocal ERG (RetiScan, 61 hexagons, first-order response). RESULTS: In the area of treatment,we found a tendency of the amplitude of the first positive deflection (P1) to decrease and of the implicit time to increase, but both effects were not statistically significant. These alterations were more pronounced in eyes with occult CNV and in myopia-related CNV. Amplitude reduction and implicit time prolongation could also be found in the areas represented by the multifocal ERG but not treated. There was no significant correlation between change in visual acuity after PDT and amplitude of the multifocal ERG. CONCLUSION: The effects of PDT on retinal function seem to be moderate as assessed by multifocal ERG. An inherent problem of this investigation was the recruitment of nontreated patients as controls. Future goals are investigations of patients with repeated PDT and of long-term alterations in multifocal ERG after PDT.

Adult↗

PubMed1998

[Undesired drug effects after taking chlormezanone (Muscle Trancopal) with lethal results].

HISTORY AND CLINICAL FINDINGS: A 34-year-old woman was admitted for treatment of toxic epidermolysis of the skin and mucosa. 16 days previously she had started to take chlormezanone (Muskel Trancopal) and some other medications for pain in the shoulder and neck. On admission she had a fever of 39 degrees C and, in addition to the epidermolysis, diffuse abdominal pain on pressure and blood-streaked stool. INVESTIGATIONS: Liver enzyme activities (GOT 979 U/I, GPT 1496 U/I, gamma GT 201 U/I) alkaline phosphatase 515 U/I), bilirubin (3.9 mg/dl) and pancreatic enzyme activities were raised. Sonography was nondiagnostic, computed tomography demonstrated only a small amount of ascites. TREATMENT AND COURSE: The epidermolytic lesions, cholestatic hepatitis and pancreatitis markedly regressed under aseptic wound treatment, antibiotics and parenteral nutrition. Persistent blood-streaked stools and bilateral pneumonia with progressive respiratory failure developed. Despite intensive medical care the patient died after 14 days from protracted sepsis with multi-organ failure. Autopsy additionally revealed adult respiratory distress syndrome and complete loss of colonic mucosa. CONCLUSION: The severe course of a toxic epidermal necrosis with fatal outcome is the first such case reported in Germany that very probably was caused by chlormezanone. 4 weeks after this case was reported to the German Doctors' Drug Commission, the manufacturers of the drug withdrew it from the market.

Acute Disease↗

PubMed1996

[Chronic open angle glaucoma: correlation of pattern electroretinography and visual field indices].

The pattern electroretinogram has already proven to be useful in detecting early stages of chronic open-angle glaucoma. We were interested in the degree of correlation between pattern ERG amplitudes and definite visual field defects. Fifteen glaucoma patients with a wide range of visual field defects were examined with pattern electroretinogram (stimulus with reversal rate of 8/s, checksizes of 0.9 degree and 6.9 degrees, covering a visual field of up to 9 degrees eccentricity). The patients' visual fields obtained with the Octopus 1-2-3 perimeter were analyzed with the perimetric analysis system PERIDATA using the indices of conformity for localized defects and the regional indices created from the mean deviation in certain parts of the 30 degrees field. In our results we were only able to find a significant correlation within the 5% level between the pattern ERG amplitudes and the sector index (large checksize, correlation coefficient r = -0.58, p = 0.03) and with the mean deviation in the region between 10 degrees and 20 degrees (small checksize, r = -0.538, p = 0.044). In summary, a marginal correlation between electrophysiological data and perimetric parameters was demonstrated. We try to explain the remarkable correlation between the amplitudes (small pattern) that were recorded from the central 9 degrees with the mean defects from the visual field peripheral of 10 degrees with the frequent combination of diffuse and localized field defects in glaucoma. Examination with the pattern ERG alone does not seem to be appropriate for grading the focal glaucomatous damage.

Adult↗

PubMed1996

[Pattern electroretinography in routine clinical diagnosis of open angle glaucoma].

According to current opinion, the pattern electroretinogram (ERG) is generated in the retinal ganglion cells. Therefore, the amplitude is expected to be reduced in diseases of the optic nerve. This leads to the conclusion that the pattern ERG might be applied in detecting ganglion cell loss in the routine clinical diagnosis of chronic open-angle glaucoma. Pattern ERGs were recorded in 15 patients with defined chronic open-angle glaucoma and 21 control individuals using a DTL fiber electrode at two different check sizes. A Fourier analysis of the ERG results reduces the subjectivity when analysing the amplitudes on screen and implies the possibility of multicentric comparability. The reliability of coordinating a value of a future patient to the correct group was estimated to 82% for the Fourier data by the bivariate discriminant analysis, based on the amplitudes of both check sizes. In this way, the relatively high interindividual variability will be partly overcome. The ability of the ERG amplitudes to separate glaucoma patients from healthy persons was determined by the AUC value, using a combination of sensitivity and specificity extracted from the ROC curves. The AUC value has its maximum at 1.0. We found an AUC value of 0.8, which confirmed the information given by the pattern ERG amplitudes. Healthy individuals and glaucoma patients cannot be separated completely by the procedure but, combined with additional clinical parameters, further validation can be achieved.

Adult↗