Biomedical subjects

U Schaudig

Publications and source records attributed to U Schaudig.

15 recordsLinked to original sources

PubMed2002

[Nasolacrimal ducts and the dry eye].

BACKGROUND: The knowledge regarding the pathogenesis, diagnosis, and treatment of dry eye has made large advances in recent years. However, many questions are still unanswered. Although the nasolacrimal ducts are part of the tear system they have been paid nearly no attention regarding dry eye. METHODS: The present knowledge about the nasolacrimal ducts is presented and discussed in a context with dry eye. A PubMED search was conducted for articles published from 1966 to the present; in addition, review articles as well as book chapters were considered and discussions with investigators in the field were performed. RESULTS: As a draining and secretory system, the nasolacrimal ducts play a role in tear transport and non-specific immune defense. Moreover, components of tear fluid are absorbed in the nasolacrimal passage and are transported into a vascular system that surrounds the nasolacrimal sac and nasolacrimal duct. This system is comparable to a cavernous body and it is connected to the blood vessels of the outer eye. Also it is subject to vegetative control. Organized mucosa-associated lymphoid tissue (MALT) is present in the nasolacrimal ducts displaying the cytomorphological and immunophenotypic features of MALT. CONCLUSIONS: The normally constant absorption of tear fluid components into the blood vessels of the surrounding cavernous body that are connected to the blood vessels of the outer eye, could be a feedback signal for tear fluid production, which comes to a halt if these tear components are not absorbed. Thus, dry eye could be initiated. Defective stimulation of tear duct-associated lymphoid tissue (TALT) could result in abnormal immune deviation at the ocular surface leading to an autoimmunological response that causes dry eye pathology.

Autoimmune Diseases↗

PubMed2002

[Final clinical indications and etiology in 1,023 enucleations. Descriptive databank evaluation with SPSS software in variable response mode with dummy variables].

BACKGROUND: A new data bank developed for ophthalmopathology using a computer-generated, multidigital data code is expected to be able to accomplish complex clinicopathologic correlations of diagnoses and signs, as provided by (multiple) clinical events and histopathologically proven etiologies, and to facilitate the documentation of new data. PATIENTS AND METHODS: In the ophthalmopathology laboratory 2890 eyes were examined between January 20, 1975 and December 12, 1996. The main diagnoses and patient data from this 22-year period were recorded. To facilitate the presentation of data, a 10-year period with eyes of 976 patients enucleated from December, 1986 to December, 1996 was chosen. Principal and secondary diagnoses served for establishing the data bank. The frequencies of successive histologic and clinical diagnoses were evaluated by a descriptive computing program using an SPSS-multi-response mode with dummy variables and a categorical variable listing of the software (SPSS version 10.0) classified as (a) non-filtered random, (b) filtered by multiple etiologies, and (c) filtered by multiple events. RESULTS: The principal groups (e.g., histologic diagnoses concerning etiology) and subgroups (e.g., trauma, neoplasia, surgery, systemic diseases, and inflammations) were defined and correlated with 798 separate diagnoses. From 11 diagnoses/events ascribed to the clinical cases, 11,198 namings resulted. CONCLUSIONS: Thus, a comparative study of complex etiologies and events leading to enucleation in different hospitals of a specific area may be performed using this electronic ophthalmopathologic data bank system. The complexity of rare disease and integration into a superimposed structure can be managed with this custom-made data bank. A chronologically and demographically oriented consideration of reasons for enucleation is thus feasible.

Causality↗

PubMed2001

[Subretinal granuloma, retinal vasculitis and keratouveitis with secondary open-angle glaucoma in schistosomiasis].

BACKGROUND: More than 250 million people in Africa and Asia currently suffer from schistosomiasis, however, ocular manifestations of this disease are rare in Germany. PATIENT AND FOLLOW-UP: We present the case of a 32-year-old patient from Gambia who had been resident in Germany for 3 years and suffered from a painful persistent diarrhoea, fever and a reduction of visual acuity (R > L). On admission, the patient reported a schistosomiasis in 1994, which was diagnosed by a skin test and was not adequately treated because of the side-effects of praziquantel. Vision was OD-0.75 sph 0.8, OS sc 1.0, IOD OD 31, OS 18 mmHg. Biomicroscopy: R > L fatty retrocorneal precipitates, especially in the lower circumference (ARLT), large inflammatory cells and Tyndall ++, vitreous with large inflammatory cells, Fundus: OD at 11 o'clock large subretinal granuloma in the periphery. Serum lysozyme was elevated (22.2 mg/l, normal range 10-17 mg/l), a syphilis stage II-III (TPHA 1:5000, VDRL neg.) and an IgG-antibody titre for Schistosoma mansoni of > 30 micrograms/ml was detected by enzyme immunoassay. In the faeces and urine no schistosoma eggs were found. Before the specific treatment for schistosomiasis could be initiated, the patient left the hospital because of reduced ocular pain due to the corticosteroids and fear of the side-effects of the treatment. DISCUSSION: In patients who present a subretinal granuloma and report a painful persistent diarrhoea, schistosomiasis, which is one of the most frequent tropical diseases should be considered, even if they have been living in central Europe for several years. Although the disease cannot become established due to the lack of specific hosts in this area, a curative treatment should be enforced in order to prevent late manifestations of chronic inflammatory organ manifestations.

Adult↗

PubMed2001

[Lacrimal duct treatment with ring intubation in injuries of the upper and lower eyelids].

BACKGROUND: Treating injuries of the lacrimal system with a silicon intubation is an approved method to prevent post-traumatic epiphora. MATERIALS AND METHODS: Between 1990 and 1999, operations were carried out on 44 patients with injuries of the canaliculi with silicon ring intubations. Interesting for us were the age distribution, causes of injuries, localisation and mid- to long-term postoperative complications. RESULTS: The age of the patients was between 1.75 and 74 years, 48% of the injuries were caused by household accidents, 23% by violence, 20% by traffic accidents and 9% by job-related accidents. The canaliculus inferior was injured in 68% of all patients. We found 10 postoperative complications, e.g. ectropia, a too long silicon ring or granuloma. We found a positive anatomical readapted lacrimal system in 88% and 12% of our patients complained of distinct to severe epiphora. CONCLUSIONS: The treatment of lacrimal laceration with a silicon intubation is an excellent method but special care should be taken with correct positioning of the lid margin.

Accidents, Home↗

PubMed2001

[Optical coherence tomography].

Optical coherence tomography has become an established method for imaging retinal diseases. It is now an accepted method for making quantitative measurements in studies on the cause and course of macular holes, vitreoretinal traction, pigment epithelial detachment, macular edema, and diabetic retinopathy. Its potential benefit in the evaluation of age-related macular degeneration and a variety of other diseases is currently under investigation. In clinical practice optical coherence tomography images add information to the biomicroscopic findings and results of other imaging techniques or functional testing and can significantly help in making critical decisions. Its future role in routine clinical practice will depend on further technical development and the results of long-term studies.

Humans↗

PubMed2001

Detection of natural peptide antibiotics in human nasolacrimal ducts.

PURPOSE: To determine the expression and production of antimicrobial peptides by mucosal cells of the lacrimal passage in healthy and pathologic states. METHODS: Detection of bactericidal-permeability-increasing protein (BPI), heparin-binding protein (CAP37), human cationic antimicrobial protein (LL-37), human alpha-defensin 5 (HD5), human alpha-defensin 6 (HD6), human beta-defensin 1 (HBD-1), and human beta-defensin 2 (HBD-2) was performed by reverse transcription-polymerase chain reaction (RT-PCR). Intracellular deposition of lysozyme, lactoferrin, secretory phospholipase A(2), human neutrophil defensins (HNP-1, -2, and -3), human beta-defensin 1 (HBD-1), and human beta-defensin 2 (HBD-2) was analyzed immunohistochemically. Samples were obtained from 15 patients by surgery and from 10 cadavers. RESULTS: RT-PCR revealed BPI, CAP37, and HBD-1 mRNA in samples of healthy nasolacrimal duct epithelium. Additionally, HBD-2 mRNA was detected in epithelial samples from patients with dacryocystitis. Messenger RNAs for LL-37 and alpha-defensin 5 and 6 were absent in all samples investigated. Immunohistochemistry revealed lysozyme, lactoferrin, secretory phospholipase A(2), and HNP-1, -2, and -3 to be present in all samples, whereas HBD-1 was present only in some of the healthy and inflamed samples. Immunoreactive HBD-2 peptide was visible only in some of the inflamed samples. CONCLUSIONS: The data suggest that the human efferent tear ducts produce a broad spectrum of antimicrobial peptides. Under inflammatory conditions, changes in the expression pattern occurred, revealing induction of the human inducible defensin HBD-2 and in some cases downregulation of HBD-1 and CAP37. Antimicrobial peptides have a therapeutic potential in dacryocystitis, in that they have a broad spectrum of antimicrobial activity and accelerate epithelial healing. However, caution is appropriate, because defensins also promote fibrin formation and cell proliferation, which are key elements in scarring processes, such as dacryostenosis.

Adolescent↗

PubMed2000

The polyurethane nasolacrimal duct stent for lower tear duct obstruction: long-term success rate and complications.

BACKGROUND: The polyurethane nasolacrimal duct stent is used as an alternative to conventional techniques for treatment of lower tear duct obstruction. The aim of this study was to evaluate the clinical success rate after a follow-up of 2 years. METHODS: Nasolacrimal duct stent implantation was attempted in 19 patients with nasolacrimal duct obstruction proven by digital substraction dacryocystography. The median age of the patients was 50 years, and the minimum duration of symptoms was 3 months. Patients were followed up 1 week, 6 months, 1 year and 2 years after the procedure. RESULTS: Eighteen stents were implanted in 17 patients without surgical complications. All stents were proven to be patent at the end of the procedure. Success rate, defined as proportion of patients free of symptoms, was 66.6%, 55.5% and 50% after 1 week, 6 months and I year, respectively, and remained unchanged thereafter. Three stents had to be removed between 6 months and 2 years after implantation. Histological examination showed granulation tissue growing into the opening and obstructing the stent in one case. CONCLUSION: Implantation of a polyurethane nasolacrimal duct stent is an alternative to conventional techniques in lower tear duct obstruction. Its overall success rate is lower than that reported after conventional dacryocystorhinostomy, but the procedure is fast, safe and reversible. Refinement of the surface and stent design may improve results in the future.

Adult↗

PubMed2000

The cavernous body of the human efferent tear ducts: function in tear outflow mechanism.

PURPOSE: To determine the structure and function of a system of large blood vessels integrated in the bony canal between the orbit and the inferior nasal duct. METHODS: Thirty-one dissected lacrimal systems of adults were analyzed by using gross anatomy, histology, and electron microscopy as well as corrosion vascular casts. RESULTS: More than two thirds of the bony canal between orbit and inferior nasal duct is filled by a plexus of wide-lumened veins and arteries. The vascular system is embedded in the wall of the lacrimal sac and nasolacrimal duct and is connected to the cavernous tissue of the inferior turbinate. Three types of blood vessels can be distinguished inside the vascular tissue that surrounds the lumen of the lacrimal passage: barrier arteries, capacitance veins, and throttle veins. CONCLUSIONS: The surrounding vascular plexus of the lacrimal sac and nasolacrimal duct is comparable to a cavernous body. While regulating the blood flow, the specialized blood vessels permit opening and closing of the lumen of the lacrimal passage, effected by the bulging and subsiding of the cavernous body, and at the same time regulate tear outflow. Other functions such as drainage of absorbed tear fluid components and a role in immunologic response are under discussion as well. Malfunctions in the cavernous body may lead to disturbances in the tear outflow cycle, ocular congestion, or total occlusion of the lacrimal passages. Variations in the conditions for swelling of the cavernous tissue may have led to the (mistaken) description of valves in the lacrimal passage.

Adult↗

PubMed1998

Limitations of imaging choroidal tumors in vivo by optical coherence tomography.

BACKGROUND: Optical coherence tomography (OCT) produces two-dimensional cross-sectional images with a longitudinal resolution of 10 microns. Its capacity for imaging retinal structure has been shown in a variety of diseases. There are no reports on its capacity and limitations in imaging choriocapillary and choroidal structures. METHODS: Twenty-two patients with the diagnosis of malignant melanoma of the choroid were submitted to OCT. We used a prototype and a commercial device, both with an 850-nm superluminescent diode with a band-width of 30 nm (reported longitudinal resolution 10 microns). The images were evaluated for retinal thickness, changes in retinal pigment epithelium, subretinal fluid accumulation and changes in choriocapillary or choroidal reflectivity. RESULTS: Retinal edema and detachment found on biomicroscopic examination for fluorescein angiography was detected by OCT in all such cases. In 2 of 22 cases small retinal detachments were detected only by OCT. Tumor extension through the retinal pigment epithelium was not seen in this series, either by biomicroscopy or by OCT. The pattern of choroidal or choriocapillary reflectivity was nonspecifically lower than that of normal choroid, but did not yield any additional information about tumor histology. When normal retina was present, the OCT appearance of a malignant melanoma resembled that of normal choroid. CONCLUSION: OCT may provide information about the retinal structure overlying prominent tumors and the extent of adjacent retinal detachment. In its present state of development, OCT is of little value in the differential diagnosis of choroidal tumors. Its potential value for the follow-up of shallow tumors needs further investigation.

Adult↗

PubMed1997

[Alpha/beta and gamma/delta T-cell receptors--analysis of conjunctival tissue of patients with ocular pemphigoid].

BACKGROUND: In the conjunctiva of asymptomatic persons and patients with ocular cicatricial pemphigoid the existence and distribution of alpha/beta- and gamma/delta-T cell receptor (TCR)-positive cells has not previously been investigated. PATIENTS AND METHODS: Biopsy specimens from 20 patients with clinically diagnosed ocular cicatricial pemphigoid (OCP) were compared with 20 specimens from asymptomatic persons. Additionally, 3 specimens from patients with OCP treated with cytotoxic drugs and 8 specimens from patients who had undergone mucosal transplantation were studied. Antigen retrieval was done in deparaffinized specimens for immunohistochemical identification of alpha/beta- and gamma/delta-TCR-positive cells by monoclonal antibodies and an appropriate detection system. All steps were performed in triplicate, and negative control sera were applied. RESULTS: alpha/beta-TCR-positive cells were observed in the conjunctival epithelium and stroma of all the asymptomatic persons and in all patients with OCP. gamma/delta-TCR-positive cells were found in 4 out of 20 patients with OCP in epithelial sites, but not in asymptomatic persons. Patients with OCP who had received cytotoxic treatment exhibited neither alpha/beta- nor gamma/delta-TCR-positive cells. Staining sites of alpha/beta-TCR-positive cells changed from membrane-bound to nuclear in patients who had undergone mucosal transplantation, and were cytoplasmic rather than membrane-bound in gamma/delta-TCR positive cells. CONCLUSIONS: This study presents preliminary evidence for the existence of distinct T-cell subsets in the conjunctiva of healthy persons and of patients with OCP. Further functional studies in fresh tissue material may provide better insights into the role of defined T-cell subsets in the immunopathogenesis of autoimmune diseases of the outer eye such as OCP.

Biopsy↗

PubMed1996

Alpha/beta- and gamma/delta-T-cell-receptor-positive lymphocytes in healthy and inflamed human conjunctiva.

BACKGROUND: The possible existence and distribution patterns of alpha/beta- and gamma/delta-TCR+ cells, which are important constituents of immune surveillance and act via the CD3+ cell complex have not yet been elucidated in the healthy and inflamed conjunctiva. MATERIALS AND METHODS: Paraffin-embedded conjunctival specimens included 18 from 18 patients with ocular cicatricial pemphigoid (OCP), 20 from 20 healthy controls, 6 from 6 patients with lye burns, and 6 from 2 patients with Stevens-Johnson syndrome; all were worked up by histology and immunohistochemistry. RESULTS: alpha/beta-TCR+ cells were visualized in the conjunctival epithelium and stroma of healthy persons, OCP, lye burns and Stevens-Johnson syndrome. alpha/ beta-TCR+ cells and a small number of gamma/delta-TCR+ cells were observed in the corneal epithelium and stroma of patients who have failing corneal grafts. After ileal mucosa transplantation to the epibulbar conjunctiva, membrane staining changes to nuclear and cytoplasmic staining. Treatment with systemic cytotoxic drugs abolishes all alpha/beta-TCR+ and gamma/delta-TCR+ cells. CONCLUSIONS: alpha/beta-TCR+ cells can be found in the non-infected epithelium and stroma of the healthy and inflamed (OCP, lye burns, and Stevens-Johnson syndrome) conjunctiva, as well as in the corneal epithelium and stroma of failing corneal grafts, whereas gamma/delta-TCR+ cells are absent. A small number of gamma/delta-TCR+ cells are present in the corneal stroma and adjacent conjunctival epithelium of patients with chronic corneal graft rejection or after transplantation of gut tissue. Further investigations may establish the role, if any, of these T-cell subsets in immune surveillance of the non-infected outer eye and in corneal graft rejection.

Burns, Chemical↗

PubMed1996

[Descemetocele after Excimer laser phototherapeutic keratectomy in herpes simplex virus-induced keratitis: a clinico-pathologic correlation].

BACKGROUND: The indications for phototherapeutic keratectomy in superficial and deep corneal scars in Herpes simplex virus infections are controversial. Serious incidents after PTK have as yet not been reported. PATIENTS AND METHODS: A 62-year-old patient had suffered from recurrent central herpetic keratitis since 1948 and was treated for corneal scarring for the first time in 1992 by PTK. In 1995, epithelial defects were noted and, since medical treatment was unsuccessful, repeat PTK was performed. Two weeks after the second PTK, stromal infiltration with a subsequent corneal ulcer was followed by a descemetocele and perforation. RESULTS: The recurrence of Herpes simplex keratitis was treated with systemic acyclovir, and the corneal perforation, the posterior synechiae and the complicated cataract were managed by a triple procedure à chaud (7.0 x 7.5 mm). The inflammation calmed down, and a significant improvement of vision was noted at dismissal. Histopathology of the corneal button showed no epithelial cells, endothelial cell rarefication, loss of Bowman's layer resulting from PTK, stromal edema, a descemetocele with perforation of 1.5 mm in diameter, and immunohistochemically Herpes simplex virus in the deep stroma and pre-Descemet. CONCLUSIONS: Considering the clinical data and the histopathology we conclude that repeat excimer laser phototherapeutic keratectomy of herpetic keratitis without antiviral coverage may result in complications.

Cicatrix↗

PubMed1995

[Prevention of postenucleation syndrome: the hydroxylapatite silicone implant. Preliminary experimental studies and initial clinical experiences].

An orbital implant after enucleation compensates for volume deficiency and increases prosthesis motility. In the literature, however, an extrusion rate of orbital implant between 10 and 25% is reported. Since the introduction of hydroxylapatic ceramics (HAC), these numbers have been reduced considerably. The HAC, which is derived from corals, has a rough surface and requires a scleral covering for implantation. The HAC, which is made in the laboratory, can be produced with smoother surfaces, so that a homoplastic covering is no longer mandatory. A composite implant was developed to improve prosthesis motility further. This consists of artificial HAC at its anterior surface to guarantee safe tissue integration; the posterior part of the implant is manufactured from silicon rubber to create a jointlike structure in Tenon's capsule. Integration of the porous HAC in the orbital soft tissues has been tested and confirmed by animal experiments. After 30 full HAC implants and 25 composite implants, only one extrusion occurred. In all other cases, compatibility proved to be excellent; transmission of the motility to the prosthesis was moderate to good. Examinations comparing prosthesis motility and computer tomographically evaluated implant motility enabled the analysis of deficits in motility transmission of the implant for the artificial eye.

Animals↗

PubMed1985

Long term efficacy of class I antiarrhythmic agents and amiodarone in patients with malignant ventricular arrhythmias.

The long term efficacy of class I antiarrhythmic drugs and of amiodarone was investigated in 34 patients with severe organic heart disease accompanied by frequent complex ventricular arrhythmias. All patients had undergone cardiac catheterisation which included coronary angiography, and each patient underwent a short and a long term study phase. During the short term study 6 class I antiarrhythmic agents were administered orally in a randomised, single-blind fashion. The drugs investigated were disopyramide, flecainide, mexiletine, prajmalium, propafenon and tocainide. The response was judged to be effective when there was a 90% reduction of couplets and a 100% reduction of salvos. For long term treatment the patient was given one of the agents found to be effective in the short term testing. Holter monitoring was performed after 1 week, and 1, 3 and 6 months. If the drug administered initially was later found to be ineffective, the patient was given another effective class I agent. If during the short term study or the follow-up phase there was no positive response to any class I agent, the patient was given amiodarone. In 78% of the patients, one or more of the class I agents administered short term was effective. The percentage of effectively treated patients after 1 week was 56%, and was 28, 14, and 9% after 1, 3, and 6 months' treatment, respectively. In amiodarone-treated patients there was an effective response rate of 40% after 10 days, 50% after 1 month and 70% after 3 and 6 months.

Amiodarone↗

PubMedDate not supplied

Structural changes of the retina in retinal vein occlusion--imaging and quantification with optical coherence tomography.

BACKGROUND AND OBJECTIVE: To evaluate the potential of optical coherence tomography (OCT) for imaging and quantifying structural changes in the retinal architecture following venous occlusive disease. PATIENTS AND METHODS: We studied 20 patients with retinal venous occlusive disease: 5 patients suffered from branch retinal vein occlusion (BRVO), and 15 from central retinal vein occlusion (CRVO). Patients with CRVO were studied within 72 hours after the first onset of symptoms. Patients were examined by OCT after a complete ophthalmologic examination including fluorescein angiography. A standard set of linear scans through the center of fixation and individual scans over areas of special interest were performed. Scans were qualitatively evaluated and quantitative measurements were performed on single A-scans at 5 locations of linear scans. Measurements were taken in the center of fixation, at the foveal rim, and at the edge of the scan. We measured total retinal thickness, thickness of cystoid spaces, and thickness of the highly reflective outer band. RESULTS: OCT produced detailed images of retinal thickening, intra- and subretinal hemorrhage, intra- and subretinal fluid accumulation, and formation of intraretinal cystoid spaces. Quantitative evaluation revealed a mean central retinal thickness of 274 +/- 181 microm (72-760 microm) in patients with central retinal vein occlusion. Visual acuity did not correlate with central or extrafoveal retinal thickness. CONCLUSION: Optical coherence tomography is a useful imaging technique for studying changes of retinal architecture following venous occlusive disease. Even minor changes like localized subretinal fluid accumulation or beginning epiretinal membrane formation can be visualized in detail. In contrast to other diseases like diabetic maculopathy, quantitative assessment of macular thickness does not correlate to visual acuity. Nevertheless, because of detailed imaging, OCT might become a useful tool in the follow-up and treatment of individual patients.

Adult↗