[Orbital metastasis of a carcinoid tumor of the small intestine].
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Aged↗
Biomedical subjects
S Behrendt
Publications and source records attributed to S Behrendt.
[Excentric lentiglobus posterior].
BACKGROUND: The posterior lentiglobe is a rare anomaly of the lens shape. Two cases of excentric protuberance of the posterior capsule are presented. To our knowledge, only one description of a similar case exists so far. PATIENTS: An eight-year-old girl (diagnosis by routine examination, V.A. 20/20) and a six-year-old boy (V. A. 20/200, esotropia) are presented. Apart from a persistent hyperplastic primary vitreous and a posterior pole cataract a vitreous cyst adherent to the posterior surface of the lens has to be considered as differential diagnosis. The etiology remains unclear. CONCLUSION: In excentric posterior lengtiglobe a good vision is possible. However, if visual acuity is impaired by posterior pole opacity or distortion of the spherical surface, removal of the lens followed by optical correction (contact lens, intraocular lens) of aphakia should be performed.
Cataract Extraction↗
[Mechanism of the formation of orbital floor fractures. Holographic interferometry studies].
To date, it has not been possible to answer the question of whether in the classic blow-out fracture the orbital floor is fractured by hydraulic force exerted by the orbital contents or by force transmission within the bony structures of the skull. The aim of our investigation was therefore to reveal the nature of orbital deformation mediated solely by the bone. In holographic interferometry the holographic image of the unstrained object is superimposed on the image of the same object after deformation. The resulting image of the object contains a pattern of interference lines representing the extent of the deformation. This image can be visualized on a TV screen after digital processing of a picture registered by a video camera. This method was used to analyze the deformation of the bony orbit by contact force applied to several points along the orbital rim (each application consisting of 1 N) and by strain distributed evenly upon the orbital rim of the human skull. In all cases maximal deformation occurred in the medial part of the orbital floor no matter where the stress was applied. This finding coincides with the fact that the majority of clinically diagnosed fractures are found in this area. In conclusion, force transmission within the bone is considered as being one determining factor for occurrence of orbital floor fractures.
Biomechanical Phenomena↗
Results of silicone oil removal from eyes treated with retinectomies.
We reviewed the results of silicone oil removal from 32 eyes that had been treated with peripheral retinectomies during vitrectomy for retinal detachment with proliferative vitreoretinopathy. With a minimum follow-up of 6 months, 3 developed a retinal detachment after silicone oil removal. Twenty-eight eyes attained a final visual acuity of 0.1 or better and 15 eyes attained 0.2 or better. Only in 3 eyes was visual acuity decreased after silicone oil removal, whereas 20 eyes showed an improvement in vision. One eye was hypotonous and 11 eyes required antiglaucomatous agents at the last examination. Final visual acuity as well as final intraocular pressure did not correlate with either the retinectomy size or with the duration of the silicone oil tamponade.
Adolescent↗
Fractionated beta-irradiation of a conjunctival lymphangioma.
Fractionated beta-radiation was applied on a conjunctival lymphangioma, which had been known for several years. Histological diagnosis was established 3 years previously. Excision was not possible because the tumor had involved a considerable part of the conjunctiva. Using a strontium-90 applicator a total dose of 30 Gy was applied in 6 fractions with 5 Gy each. The initial tolerance was satisfactory. No radiogenic damage occurred, an involution of the tumor could be observed. During a follow-up time of nearly 2 years no further progression was noted. We consider the beta-radiation as an interesting therapeutic alternative for conjunctival lymphangiomas which are difficult to treat surgically due to their size.
Beta Particles↗
[Incidence of retinal detachment after treatment with the Nd:YAG laser].
Two hundred fifty patients were examined after Nd:YAG laser capsulotomy and 330 patients retrospectively after Nd:YAG laser iridotomy. Retinal detachment followed in 3.6% of the capsulotomies. No correlation was found between the number of exposures or applied total energy and the risk for retinal detachment. The risk for retinal detachment, however, was found to be increased considerably by myopia and aphakia. After iridotomy, retinal detachment occurred in only one case, although similar energy levels were used for both procedures.
Follow-Up Studies↗
[Postoperative necrotizing sclerokeratitis].
Two cases of necrotizing sclerokeratitis following uncomplicated extracapsular cataract extraction are reported. Enucleation became necessary in the first case despite initially successful immunosuppressive treatment. In the second case, a stable condition was achieved by covering the affected area with a patch of lyophilized dura. Two years later, however, phthisis bulbi developed.
Aged↗
[Ocular outflow resistance and rate of secretion of aqueous humor following iridotomy and posterior capsulotomy with the Nd:YAG laser].
When the Nd:YAG laser is used for iridotomy and posterior capsulotomy an elevation in the intraocular pressure (IOP) is often found within the first few postoperative hours and in some cases for even 1-3 days. In 39 eyes the changes in postoperative intraocular pressure were noted and the preoperative as well as the postoperative outflow facility and aqueous secretion flow measured by oculopressiontonometry. The results demonstrated that in both iridotomy and posterior capsulotomy a reduction in the outflow facility caused the postoperative rise in IOP. Aqueous secretion flow did not increase. Most iridotomy patients had glaucoma and consequently reduced preoperative outflow facility. This determined the postoperative IOP elevation. In capsulotomy patients, no such correlation was evident, but the role of the laser energy applied seems to be more important according to our results.
Aqueous Humor↗
[The effect of posterior chamber lenses or YAG laser capsulotomy on sensitivity to glare and twilight vision in comparison to phakic control groups (corrected)].
Patients who had undergone extracapsular cataract extraction with implantation of a posterior chamber intraocular lens, and normal subjects of corresponding age and vision were examined with the mesoptometer and nyktometer to compare their twilight vision and glare sensitivity. All the results were poorer in patients with intraocular lenses. Statistically, some of the differences in the results of examinations performed in the two groups were highly significant. As the controls were strictly matched in age and visual acuity, these results confirm other studies with similar objectives. Additionally, some patients with posterior chamber lenses were examined who had also undergone YAG laser capsulotomy for secondary cataract. Although the number of cases was too small for statistical evaluation, it appeared that in this group twilight vision and glare sensitivity could not be improved in the same way as daylight visual acuity by means of this treatment. These findings indicate that since intraocular lenses are increasingly being implanted in younger patients, special attention should also be paid to scotopic vision and glare sensitivity during examinations for drivers' licenses, particularly in cases of good daylight vision. Special examinations, e.g., with the mesoptometer or nyktometer, should be carried out in all such cases. Increased glare sensitivity in eyes with lens implants should also be taken into consideration with regard to the increasing importance of computer and TV screens.
Adaptation, Ocular↗
Infrared microspectrometry of capillary gas chromatography effluents and of gas-phase free radicals.
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Chemical Phenomena↗
Evaluation of laser sclerostomy fistulas using ultrasound biomicroscopy.
BACKGROUND: Laser sclerostomy is a relatively new technique in glaucoma surgery. Clinical examination, particularly of the intrascleral part of laser sclerostomy fistulas, is difficult. We performed ultrasound biomicroscopy (UBM) in order to determine, if it were possible to visualize fistulas. Moreover, it was the aim to investigate whether this imaging technique could provide additional information on fistula morphology. PATIENTS AND METHODS: Ten eyes of eight patients with chronic open angle glaucoma who had undergone erbium-YAG laser sclerostomy ab externo were examined using a UBM-probe with a 20 MHz transducer providing spatial resolution of approximately 80 microm. RESULTS: Radial scanning allowed visualization of the sclerostomy fistula in nine of ten eyes. The different functional state of sclerostomy fistulas correlated well to UBM findings. It was possible to image differences in the morphology of occluded and patent fistulas and to visualize the filtering pathway in functioning blebs. CONCLUSIONS: Ultrasound biomicroscopy allows imaging of laser sclerostomy fistulas. UBM and clinical findings correlated well in the majority of the patients we examined. The technique supplements clinical examination and in some cases may provide additional information.
Aged↗
Ultrastructural and immunohistochemical findings after linear excimer laser keratectomy.
BACKGROUND: One human pathology specimen has been studied previously following the use of the excimer laser for the correction of astigmatism. We report histopathologic findings following linear corneal excisions with the excimer laser. METHODS: A 193 nm excimer laser was used to create symmetrical, transverse excisions in a human eye to correct astigmatism. Three months later, a full-thickness corneal transplant was performed due to unsatisfactory refractive results. The excised corneal button was examined with light microscopy, transmission electron microscopy and immunohistochemistry. RESULTS: An area 10 to 20-micron wide was observed between the epithelial cells within the keratectomy and the sharply dissected stromal lamellae. This area stained positive for laminin and pro-collagen type III. Some epithelial cells showed processes reaching into this area. Descemet's membrane, immediately underneath the area of the keratectomy, contained atypically striated collagen fibers. CONCLUSIONS: These findings demonstrate wound healing changes similar to those reported following diamond knife keratotomy and photorefractive keratectomy for myopia. The changes in the posterior cornea are similar to those previously reported when an excimer laser beam approached Descemet's membrane.
Aged↗
Bilateral cataract after phakic posterior chamber top hat-style silicone intraocular lens.
BACKGROUND: New strategies have been developed for surgical treatment of high myopia. Recently, implantation of minus power posterior chamber intraocular lenses (IOL) into phakic eyes has been introduced. METHODS: We report a 37 year-old female patient who developed bilateral anterior subcapsular cataract 7 years after minus-power, top hat-style silicone posterior chamber IOL implantation in Russia. The corrected visual acuity was right eye 20/200 and left eye 20/63. Because of the high myopia and the posterior chamber IOL in her phakic eyes, biometry for IOL calculation gave contradictory results. Both posterior chamber IOLs were found to be adherent to the crystalline lenses. After posterior chamber IOL explantation and phacoemulsification, intraoperative retinoscopy was performed. With this aphakic refraction, the IOL power was calculated and implanted. The explanted posterior chamber IOLs were examined by scanning electron microscopy. RESULTS: After bilateral operation the corrected visual acuity increased to right eye 20/32 and left eye 20/40, respectively. On scanning electron microscopy, a membranous structure of unknown origin was noted on the entire surface of the explanted posterior chamber IOLS. CONCLUSION: There is a potential risk of cataract formation after implantation of this top hat-style silicone posterior chamber IOL. If cataract extraction in this specific situation is needed, a different approach for calculating the aphakic IOL power is necessary, such as intraoperative retinoscopy.
Adult↗