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The specialized areas of the carapace of Argulus foliaceus hitherto known as respiratory areas, are most probably identified as iontransporting epithelia by electron microscope and histochemical investigations. [ABSTRACT FROM AUTHOR]

With a retrospective Follow-up essay under the use of Matched peer variables the wellbeing course was examined by patient pairs (128 patients) assigned to 64 individually with fractures of the anterior arm shaft. A group which treats others with 2.7 or 3.5 mm DCP/LC-DCP got with the AO Point Contact basic gate (PC-Fix). The well-being course data count after the implantation on a period of 18 months. The Follow-up-rate was 100% for this time period. The patients became for each other on reason of the criteria: assigned to fracture classification, soft partial loss, accompanying injuries and age. Possible complications were: implantation conditional nerve damages, infections, implant failures, delayed healings, pseudarthroses, motion reductions and synostoses. Complications appeared (PC-Fix at 13 patients: respect, DCP: 5). The statistical testing didn't yield any statistically significant advantage for one for the two implants at a p-value of 0.5811 for.

Background: Strabism usually impairs central stereopsis irreversibly after a short time duration,however, the retinal periphery is more resistant to deterioration by binocular impairment., Methods: In this prospective study 46 strabismic patients (9-56 years old) were tested for dynamic stereopsis in the peripheral visual field up to 20 degrees eccentricity. The effect of realignment of the visual axes by surgery on dynamic stereopsis was tested before and after surgery in 40 out of these patients. Patients were tested qualitatively for dynamically stereoactive fields of vision and quantitatively for the threshold value needed to create a three-dimensional impression., Result: We found residual dynamic stereopsis in 30% of patients without central static stereopsis: 56% of the patients improved after surgery, either through a significant (p<0.01) gain of stereoactive fields or through a decrease of threshold values., Conclusion: Strabismus surgery has benefits for the patients outside classical tests and seems to be independent of the static depth perception.

Introduction: Julesz named the ability of depth perception in random dot stereograms as "global stereopsis". At present there are only high-density random dot stereograms with different disparities in use in the ophthalmological practice. The aim of our exploration is to measure the effects on pattern recognition and depth perception by thinning out the dot density in random dot stereograms down to very low levels (< 1%)., Methods: Experiments were performed by 43 volunteer observers using two sequences of random dot stereograms. Each sequence has its own constant disparity and within a sequence the dot density decreased to values less than 1%. Additionally we compared the performance in these tests with the performance in the conventional haploscopic stereoscopic tests (Titmus, TNO, Randot)., Results: Of the observers 48.8% (n = 21) were able to establish a complete depth perception and pattern recognition ("global stereopsis") at a matrix dot density of 0.3% and a disparity of 730" (12, 17'). Another group of subjects (48.8%, n = 21) saw the sub-matrix at 0.3% dot density in depth as a star field ("local stereopsis") but was not able to recognise the form of the sub-matrix. A significant correlation does not exist between these results and those from the conventional stereoscopic test., Discussion: We assume from these results that the very low density random dot stereograms measure a new quality of stereoscopic vision, from which we can obtain information about the density of cortical binocular activated elements in the human brain.

The plenty options and high quality of radiation therapy for non-malignant disorders is not well known outside the field of radiology. It is necessary to transfer this information to cooperating general practitioners, surgeons, orthopedics and other specialists. To warrant quality assurance and quality control and to allow a uniform performance of radiotherapy of non-malignant conditions, general guidelines and recommendations according to the German Working Group of Scientific Medical Societies are useful. This paper summarizes the essential aspects of radiotherapy for non-malignant diseases: indication of, informed consent for, documentation and conduct of radiation therapy for non-malignant diseases using orthovoltage equipment and specific recommendations for follow up examinations. Radiotherapy concepts for non-malignant diseases are summarized.

Background: The treatment of persistent postoperative lymphatic fistulas or lymphoceles is often a problem. Approximately 2% of patients will develop lymphatic fistula after vascular surgery. This can require a long lasting conservative therapy. If spontaneous cure fails, a second operation with wound revision becomes necessary. We studied low-dose percutaneous radiotherapy to be used as an alternative treatment in addition to conservative or surgical therapy., Patients and Methods: Between 1989 and 1998 29 patients (25 with lymphatic fistulas, 4 with lymphoceles) received radiation therapy. Depending on the depth of the fistula 27 patients were treated with electrons (7 to 18 MeV). Two other patients suffering of retroperitoneal lymphoceles received a treatment with photons (15 MV). In all patients the fractionation was 4- to 5 x 1.0 Gy/week and the dose ranged from 3 to 12 Gy depending upon the onset of the radiation therapy effect., Results: In 27 of 28 evaluable patients a complete disappearance of the fistula or lymphocele was achieved by radiation during therapy or shortly afterwards. In 1 case no benefit was observed after a dose of 11 Gy. This patient required further surgery with wound exploration., Conclusion: Low dose percutaneous radiotherapy (up to 10 to 12 Gy) is effective to heal lymphatic fistulas and lymphoceles without complications. Individual dosage is required because doses even lower than 10 Gy may be effective. Radiation can be effective even after a failed conservative therapy or instead of surgery.

Background: Optic gliomas are frequently associated with neurofibromatosis type 1 (NF1) and belong to the diagnostic criteria of NF1. Different growth rates require differentiated strategies for screening and observation., Patients and Methods: 29 patients (25 children < 11 years, 4 adults > 18 years) with visual pathway tumors and NF1 were examined neurologically, ophthalmogically, by means of MRI and VEP. Results were set into context with preceding investigations (mean follow up time 6.5 years)., Results: 11 children showed a stable condition, 14 an unfavorable process with substantial loss of vision. Children with an unfavorable process showed a lower age at diagnosis (3.2 versus 5.8 years; p < 0.05), more frequently strabism (11/14 versus 1/11; p < 0.05), optic atrophy (12/14 versus 1/11; p < 0.05), pathological VEP (9/9 versus 2/10; p = 0.001), visual field defects (9/9 versus 1/9) and involvement of the optic chiasm (11/14 versus 3/11; p < 0.05) than children with a stable condition. 3 of 4 adults had no visual symptoms despite involvement of the optic chiasm., Conclusions: The crucial prognostic factor is the patient's age at the time of diagnosis. Optic gliomas which become symptomatic in early childhood (< 6 years) grow rapidly and require frequent ophthalmologic investigations and MRI. Tumors diagnosed in late childhood (> 6 years) do not progress, allowing for gradual extension of intervals between ophthalmological investigations.

Background: Radiation therapy of benign diseases is controversially discussed and rarely applied in Anglo-American countries, while in other parts of the world, especially Central and East Europe, it is commonly practised for several benign disorders. Similar to the European Society of Therapeutic Radiology and Oncology survey, a patterns of care study was performed in Germany., Method: A questionnaire was mailed in 3 years (1994, 1995, 1996) to all radiation facilities in Germany, which assessed equipment, indications, number of patients and treatment concepts. A total of 134 (88%) institutions returned all requested data: 22 in East and 112 in West Germany; 30 in university and 104 in community/private hospitals. The average data of each institution and of all institutions were analyzed for frequencies and ratios between different regions and institutions., Results: A mean of 2 (range 1 to 7) megavoltage (Linac/Cobalt 60) and 1.4 (range 0 to 4) orthovoltage units were available per institution; 32 (24%) institutions had no orthovoltage equipment. A mean of 20,082 patients were treated per year: 456 (2%) for inflammatory diseases (221 hidradenitis, 78 nail bed infection, 23 parotitis, 134 not specified), 12,600 (63%) for degenerative diseases (2,711 peritendinitis humeroscapularis, 1,555 epicondylitis humeri, 1,382 heel spur, 2,434 degenerative osteoarthritis, 4,518 not specified), 927 (5%) for hypertrophic diseases (146 Dupuytren's contracture, 382 keloids, 155 Peyronie's disease, 244 not specified), 1,210 (6%) for functional disorders (853 Graves' orbitopathy, 357 not specified), and 4,889 (24%) for other disorders (e.g. 3,680 heterotopic ossification prophylaxis). In univariate analysis, there were significant geographical (West vs East Germany) differences in the use of radiotherapy for inflammatory and degenerative disorders and institutional differences (university vs community/private hospitals) in the use of radiotherapy for hypertrophic and functional disorders (p < 0.05). The prescribed dose concepts were mostly in the low dose range (< 10 Gy), but varied widely and inconsistently within geographic regions and institution types., Conclusion: Radiotherapy is a well accepted and frequently practised treatment for several benign diseases in Germany, however, there are significant geographical and institutional differences. As the number of orthovoltage units decreases, an increasing patient load is in demand of more megavoltage units, which may compromise the cost-effectiveness of this treatment. Only 4% of all clinical institutions are involved in controlled clinical trials. To maintain a high level of radiotherapy service to other disciplines, radiotherapy treatment guidelines, quality control and continuing medical education are required.

Background: Neurofibromatosis 2 (NF2) is a rare autosomal dominant disorder (prevalence 1:37.000) associated with changes in tumor suppressor genes. Intraocular manifestations have been reported as subcapsular cataract, retinal hamartomas, epiretinal membranes, keratopathy in facial palsy, and tumors of the nerves I-V are typical ocular manifestations of NF2., Patients and Materials: We prospectively examined 7 patients who met the diagnostic criteria of NF2 with regard to retinal changes using fluorescence angiography and red-free fundus photography., Results: In four patients, we found window defects of the pigment epithelium in the macular or paramacular areas. In one patient we observed a combined pigment epithelial and astrocytic hamartoma. A choked papilla was found in two patients., Conclusions: Presumably, retinal changes in NF2 occur more frequently than has been assumed previously. Our results confirm that in NF2 patients more attention should be paid to abnormalities of the optic disk, the retina and the choroid.

Background: The results of nearly automated computerized determination of visual acuity by PC are compared to those of card measurements. The introduction of a new measuring technique should not change the dimension--visual acuity--itself, therefore there should be no difference between the results of the conventional technique and those of the PC., Methods: Both methods were tested in a group of subjects (N = 100) with vision between 0.1-2.5. The nearly automated technique was developed and established by our department. Like the conventional method it keeps strictly to the DIN rates. For DIN-criterion we chose for the benefit of high reproducibility 6/10., Results: In spite of some deficiencies in the presentation of the Landoltrings on the monitor, our analysis presents a surprisingly good correspondence between the results of the two methods. In the analysis, we are not comparing arithmetic mean values. Instead, we examine the individual difference between the two methods in acuity steps and its these distribution within the group of subjects. No statistically provable difference can be detected. This is valid for both single visual acuity and for visual line acuity, which can also be tested with the computer aided method., Conclusion: We conclude that the PC proves to be an equivalent method to the measurement with cards. Thus, it is suitable for the use in daily routine of vision examination with the advantage, that the investigator has less influence on the outcome of the test.

Background: The examination of fixation on the fundus oculi is one of the main points in the diagnosis of amblyopia. Therefore it is necessary to describe the fixation ability and to clarify at what age children can fixate foveally and at what age this examination can be carried out, considering not only physiological aspects, but also co-operation reasons., Patient and Methods: Fixation on the fundus oculi was examined in 111 children aged between 1 and 25 months with the ophthalmoscop-star. This examination was carried out in 64 cases by a second and in 15 cases by a third examiner on the same day., Results: During the first 3 months of age children cannot fixate foveally, one can observe instead, a kind of scatter at the posterior pole in a diameter of about 5 degrees. In the course of the 4, and 5, month of age foveal fixation develops. Repeated examinations of the same child on the same day by a 2, and 3, examiner reveal a very high rate of accordance (78%) of their results., Conclusions: The examination of fixation on the fundus can be carried out at 4 to 5 months of age. At that age one can differentiate quite reliable between a foveal and eccentric fixation as well as scatter at the posterior pole. The rate of accordance 78% with this fixation examination by several examiners shows that same reliability of this examination carried out in school children and adults. Comparing this result with fixation examination carried out with the Haidinger brushes then one must calculate with a fault rate of about 20% when examining with the ophthalmoscope, considering that the examination with Haidinger brushes as a reference examination.