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Biomedical subjects

G Duncker

Publications and source records attributed to G Duncker.

At least 19 recordsLinked to original sources
PubMed2006

[Molecular genetic and histopathological examinations for genotype-phenotype analysis in patients with TGFBI-linked corneal dystrophy].

PURPOSE: Different missense mutations in the TGFBI gene cause granular (Groenouw CDGG1, Avellino CDA, Reis-Bücklers CDB1) and lattice (Type I; Biber-Haab-Dimmer; CDL1) corneal dystrophies and, in some reports, corneal dystrophy Thiel-Behnke (CDB2). We report on the mutation spectrum and the genotype-phenotype correlations on the basis of clinical and histopathological examinations of 13 German families with TGFBI-linked corneal dystrophies. METHODS: In 31 patients with different corneal dystrophies, DNA was extracted from leukocytes of the peripheral blood and mutation analysis was performed by direct sequencing of the TGFBI gene. Clinical and histopathological findings were compared with the molecular genetic findings for genotype-phenotype correlations. RESULTS: In 6 patients (2 families/one single person) with clinical and histopathological CDL1 we found a Missense mutation Arg124Cys and in 7 patients (3 families/one single person) with clinical and histopathological CDA we found a Missense mutation Arg124His in the exon 4 of the TGFBI gene. In 12 patients (4 families/2 single persons) with clinical and histopathological CDGG1 we found a Missense mutation Arg555Trypt in the codon 12 of the TGFBI gene. In all five patients (1 family/4 single persons) with clinical and histopathological CDB2 we could not find any mutation in the TGFBI gene. In one patient with exceptional clinical and histopathological findings we found a Missense mutation Ala546Asp, which was reported before only twice in connection with polymorphous corneal amyloidosis. CONCLUSIONS: In comparison of our clinical and histopathological findings and the molecular genetic results we found a strong genotype-phenotype correlation in patients with TGFBI-linked corneal dystrophies. Rare mutations can lead to exceptional clinical and histopathological findings which cannot be classified into the different groups of corneal dystrophies. In our patients with CDB2 we could not find any molecular genetic correlation to the TGFBI gene.

Adult↗
PubMed2006

[Principals and clinical applications of optical coherence tomography in glaucoma].

Optical coherence tomography (OCT) supplies morphological information from different retinal layers. In glaucoma, analysis of the nerve fiber layer is gaining more and more significance: Losses in this layer often precede by years functional losses in the visual field and end up in optical nerve head changes. OCT offers a means for imaging and for measurement of the nerve fiber layer besides morphological analysis of ONH as one of the earliest sensitive parameters in modern glaucoma diagnostics. However, because of the lack of extensive comparative data, the priority use of optical coherence morphometry is to be seen mainly in intraindividual follow-up.

Glaucoma↗
PubMed2005

[The autologous ipsilateral rotating penetrating keratoplasty: an early surgical procedure to prevent deep irreversible amblyopia in Peters anomaly].

PURPOSE: It is a challenge to prevent irreversible amblyopia in infants suffering from Peters anomaly. In some cases of centrally located corneal opacifications an optical sector iridectomy can not lead to a clear optical axis. The homologous penetrating keratoplasty as early surgical procedure has shown an extremely poor outcome with a high risk of irreversible graft failure. We report on the autologous ipsilateral rotating penetrating keratoplasty in an eight-week-old infant suffering from Peters anomaly. PATIENTS: An autologous ipsilateral rotating penetrating keratoplasty was performed in an eight-week-old infant suffering from Peters anomaly to prevent irreversible amblyopia. RESULTS: After a follow-up time of 8 months we saw a clear graft within the optical axis without any complications in wound healing. We removed the single sutures two months after keratoplasty. Postoperative astigmatism could be corrected first by fitting a special nursery contact lens and after reduction of astigmatism because of suture removal we fitted special nursery glasses. The intraocular pressure remained within the normal range during the follow-up period. CONCLUSION: The autologous ipsilateral rotating penetrating keratoplasty should be considered superior to homologous keratoplasty in infants with Peters anomaly if sector iridectomy is not advisable because of a central corneal opacification. Resulting high refractive errors can be successfully corrected by special contact lens fitting or by nursery glasses.

Amblyopia↗
PubMed2005

[Lidloading and intraocular pressure].

BACKGROUND: Implantation of rigid gold or platinum lid weights (lidloading) represents the most common method for therapy of patients with lagophthalmus as a result of facial palsy. In a more recent approach also flexible platinum chains have been used. Glaucoma has frequently been described as a contraindication for lidloading. The aim of this study was to proof if lid weights lead to an increase of the intraocular pressure (IOP). PATIENTS AND METHODS: In a prospective study the IOP has been measured before and after implantation of 46 rigid gold implants and 39 flexible platinum chains in patients with paralytic lagophthalmos. RESULTS: Neither the implantation of rigid gold implants nor the use of the flexible platinum chain lead to a statistically significant change of the IOP. There was also no difference between the two groups. CONCLUSION: With this study we could demonstrate that glaucoma is not an absolute contraindication for the use of lid weights in patients with paralytic lagophthalmos. Moreover a lid weight is easily removable if complications should occur.

Contraindications↗
PubMed2004

[Intraocular non-Hodgkin's lymphoma and its therapy-- a case series of ten patients].

BACKGROUND: The timely and correct diagnosis of intraocular non-Hodgkin's lymphoma represents a huge challenge to clinicians. Two thirds of intraocular lymphomas are a manifestation of a primary CNS lymphoma (PCNSL) arising outside the lymphatic system and are localized in the brain, the meninges or the spinal chord. Ten to twenty percent commence as vitreous or retinal infiltrates mimicking uveitis. Ninety five percent of PCNSL are B cell lymphomas. PATIENTS: Three exemplary cases from a group of ten patients treated between 1998 and 2002 are presented. A table provides a summary of the relevant details of all ten patients. RESULTS: The mean age at presentation was 63.5 years with a female to male ratio of 6 to 4. Nine patients were diagnosed as having intermediate or posterior uveitis, in one patient choroidal metastases were suspected. Six patients had a concomitant CNS lesion while four patients showed isolated intraocular lymphoma only. The presence of a highly malignant B cell lymphoma was proven by vitreous biopsy in nine cases and by stereotactic biopsy of a CNS lesion in one patient. All patients were treated by intravenous chemotherapy, however, no binding recommendations with regard to treatment exist to date. CONCLUSIONS: We give an overview of all current treatment regimens and their pitfalls. At present it is recommended that all patients with proven PCNSL be entered in a multicenter randomized study under the auspices of the Department of Internal Medicine III of the Benjamin-Franklin-University-Hospital, Berlin and the Department of Neurology of the University Hospital of Tuebingen.

Aged↗
PubMed2001

[Antimicrobial decontamination of corneal donor material: infection prevention and quality assurance].

BACKGROUND: Microbiological examinations in eye banks have found an increased contamination rate in preservation media. We studied the effect of prolonged submersion time for decontaminating donor globes. MATERIALS AND METHODS: We retrospectively analyzed the primary contamination of conjunctival smears in 76 cornea donors. The submersion time of donor eyes in PVP iodine solution before preparation was prolonged from 1 min to 5 min, and the contamination rate of storage vessels was compared. RESULTS: In 13 of the 76 conjunctival smears we found no contamination. Before prolonging submersion time, the preservation medium was contaminated in 15 cases, but after 5 min no contamination was observed. CONCLUSION: Prolonging the submersion time of donor globes from 1 to 5 min was effective. The model presented here provides guidelines for existing eye banks as well as for those yet to be established.

Antisepsis↗
PubMed2001

Morphological and functional changes due to drug-induced lysosomal storage of sulphated glycosaminoglycans in the rat retina.

UNLABELLED: A series of dicationic amphiphilic drugs, most of them immunomodulatory agents, are known to induce generalised lysosomal storage of sulphated glycosaminoglycans (GAGs) in rats and in cultured cells of several species including man. The present study deals with the cytological effects of two experimental immunomodulatory acridine derivatives upon the retina of rats. The animals were treated orally with compound CL-90.100 (3,6-bis[2-(diethylamino)ethoxy]acridine) or an analogue for periods up to 22 weeks at a dose range of 60-90 mg/kg body weight and the retinae examined by light and electron microcopy. ERG measurements were done initially and after 16 weeks of treatment. All types of retinal cells developed abnormal cytoplasmic vacuoles which represented the ultrastructural counterpart of lysosomal GAG storage as demonstrated by histochemical and cytochemical staining experiments. The retinal pigment epithelium and the Müller cells were most prominently affected, photoreceptor cells to a lesser degree, and retinal neurons to varying degrees. The topographical distribution of the drug as detected by fluorescence microscopy closely resembled the distribution of the GAG accumulation in the retinal layers. After treatment for 16 weeks, the a-and b-wave amplitudes in the ERG were significantly reduced compared with the controls. CONCLUSION: the glycosaminoglycan storage in pigment epithelium is reminiscent of that seen in some inherited mucopolysaccharidoses of humans. When a given cell type shows lysosomal accumulation of glycosaminoglycans as a consequence of impaired degradation, it can be assumed to be engaged in the turnover of glycosaminoglycans under normal conditions. Thus the present results suggest that not only the retinal pigment epithelium but also Müller cells, photoreceptor cells, and, to variable degree, retinal neurons are normally involved in the catabolism of sulphated glycosaminoglycans. We believe that the lysosomal storage of glycosaminoglycans caused secondary cellular disturbance responsible for the functional changes shown by electroretinography.

Acridines↗
PubMed2000

[Bilateral inferior hemianopsia as an early symptom of Heidenhain type Creutzfeldt-Jakob disease].

BACKGROUND: The Heidenhain variant is a subtype of Creutzfeldt-Jakob disease (CJD) where visual symptoms are leading. HISTORY AND SIGNS: We report on a 60-year-old woman who developed within a few weeks bilateral inferior hemianopsia. Morphological findings of the eyes were normal. Neurological examination and cerebral CT/MRI were normal too. P 100 latency of visual evoked potentials (VEP) of both eyes, however, was delayed. OUTCOME: During the course of the disease visual field narrowed progressively and 3 months after the first symptoms the patient went blind. Only at that time myoclonia, hyperkinesia, and psychiatric symptoms appeared. Changes of EEG and cerebrospinal fluid were suggestive of Creutzfeldt-Jakob disease (CJD). The patient died after 5 1/2 months and diagnosis was confirmed neuropathologically with mainly occipital spongiform encephalopathy. CONCLUSION: This case illustrates the diagnostic difficulties of the Heidenhain type of CJD and demonstrates that in patients with progressive visual field defects without morphological abnormalities of the eyes or radiological abnormalities of the brain CJD should be considered. It should be looked out for additional neurological (especially extrapyramidal) and psychiatric symptoms.

Creutzfeldt-Jakob Syndrome↗
PubMed1999

[Corneal astigmatism as a special complication after lid-loading in patients with lagophthalmos].

UNLABELLED: Lid-loading with precious metals, described by Illig in 1958, has become increasingly important. because of its good functional and cosmetic results this method is superior to tarsorrhaphy. Furthermore, lid-loading can be combined with additional surgical techniques to achieve more dynamic lid-closure. In a prospective study we examined the results after lid-loading and discuss postoperative changes of the cornea. PATIENTS AND METHODS: Between May 1994 and June 1998, 36 patients with peripheral facial paresis and lagophthalmos were treated with a pretarsally fixed upper-lid implant. We used 99.99% gold for the implants with a weight of 1.5 g on average. RESULTS: In all cases we obtained sufficient postoperative lid closure which resulted in a statistically significant reduction in lagophthalmos and improved keratopathy. Postoperative complications were: pseudoptosis, remaining lagophthalmos, bulge, extrusion, migration and corneal astigmatism. Depending on the implant pressure, an astigmatism of 1-2 D developed in the vertical meridian. In all cases the initial visual acuity was reached by an ordination of cylindrical glasses. CONCLUSIONS: So far, corneal astigmatism as a complication after lid-loading has not received much attention in the literature. In our opinion, the development of astigmatism is caused by implants that are too heavy, an incorrect implant radius and individual cofactors (consistency of lid and cornea). There has been no need for an explantation in any case.

Adult↗
PubMed1999

[Examination of resistance of the lens capsule against the waterjet].

BACKGROUND: Although cataract surgery is highly developed today, there are still problems such as secondary cataract. In polishing the posterior capsule lens, epithelial cells often remain, causing secondary cataracts. Additionally, there are the problems of tissue heating and endothelial cell loss during phacoemulsification by ultrasound. This could be another field for improvement of cataract surgery by using the waterjet. METHODS: After removing the cornea of freshly enucleated porcine bulbs, we used the water jet from 4 to 12 bar. The hit angel on the capsule varied between 45 degrees and 90 degrees. RESULTS: Rupture of the posterior capsule occurred at a mean of 8.5 bar using the jet at 45 degrees and a mean of 8.6 bar using the jet at 90 degrees. CONCLUSION: The waterjet pressure should not be over 4 bar during polishing of the posterior capsule.

Animals↗
PubMed1999

[Severe intra- and postoperative supra-choroid hemorrhage. Risk factors, therapy, results].

BACKGROUND: The aim of this study was to analyze risk factors, therapeutic strategies, and functional and anatomic results of eyes with severe suprachoroidal hemorrhage. PATIENTS: Eight of 11 bleeding episodes occurred intraoperatively and 3/11 postoperatively. Bleeding was associated with the following surgical procedures: perforating keratoplasty (5x), extracapsular cataract extraction (3x), pars plana vitrectomy (2x), intracapsular cataract extraction (1x). RESULTS: Nine operations were performed with general anesthesia, two after retrobulbar injection. Ocular risk factors (e.g., prior operations, ocular diseases) and general risk factors (e.g., cardiovascular diseases, diabetes) were analyzed. At the end of the follow-up time visual acuity had improved in three eyes, and it was unchanged in one eye and worse in seven eyes. Four eyes were amaurotic; two of them had to be enucleated. CONCLUSIONS: In spite of using state-of-the-art surgical techniques the prognosis of suprachoroidal bleeding remains serious. Patients who have a combination of several ocular and general risk factors almost exclusively are the ones who afflicted by this complication.

Adult↗
PubMed1999

Early expression of proinflammatory cytokines interleukin-1 and tumor necrosis factor-alpha after corneal transplantation.

This study's aim was to determine the early postoperative expression of proinflammatory cytokines interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) by corneal grafts. BALB/c (n = 90) and C57BL/6 (n = 90) murine recipients were grafted with donor corneas from either syngeneic or allogeneic mice. At 7 and 14 days after surgery, corneal grafts were excised and the recipient rims separated from the donor tissue. Corneal segments were cultured and assayed for cytokines by enzyme-linked immunosorbent assay (ELISA). There was profound upregulation in expression of both IL-1alpha and TNF-alpha after corneal transplantation. Among both low-rejecting BALB/c and high-rejecting C57BL/6 hosts, levels of IL-1alpha were significantly (p < 0.01) more marked in allogeneic as compared to syngeneic grafts. TNF-alpha overexpression was similarly more marked in allogeneic as compared to syngeneic grafts in both BALB/c and C57BL/6 hosts, although the difference was generally more marked among high-rejecting C57BL/6 recipients. In the case of both IL-1alpha and TNF-alpha, the principal source of cytokine expression in the transplanted tissue was the recipient rim. There is significant overexpression of both IL-1alpha and TNF-alpha during the first 2 weeks after transplantation in both syngeneic and allogeneic orthotopic corneal grafts. However, whereas in syngeneic grafts cytokine expression generally decreases after the first postoperative week, significantly elevated cytokine levels are sustained in allogeneic grafts, implicating IL-1 and TNF-alpha as mediators of the alloimmune response in corneal transplantation.

Animals↗
PubMed1998

[Potential of the water jet in cataract surgery].

UNLABELLED: Though cataract surgery is highly developed today, there are still problems such as endothelial cell loss after surgery and the occurrence of aftercataract. To reduce these complications we looked for techniques with a high degree of safety and precision. We found the water jet, an instrument already well established in liver surgery. We tested the possibility of improving the results of cataract surgery using the water jet method. METHODS: We performed cataract surgery--phacoemulsifikation and polishing of the capsule--on freshly enucleated porcine bulbs using water jet and by conventional procedures. By scanning electron microscope examination we compared the results. Additionally we emulsified human lens nuclei obtained by extracapsular cataract extraction using the water jet. RESULTS: The epithelial cells and lens fragments on the capsule were considerably reduced after the water jet procedure. CONCLUSION: The results show the possibility of improvement of cataract surgery by using the water jet. Further studies are necessary to adapt this technique to routine surgery in humans.

Animals↗
PubMed1998

Effects of the pharmaceutical cosolvent hydroxypropyl-beta-cyclodextrin on porcine corneal endothelium.

BACKGROUND: The influence of the pharmaceutical cosolvent hydroxypropyl-beta-cyclodextrin (HPBCD) on porcine corneal endothelium was investigated. The purpose was to find out if this substance causes severe damage to the cornea. METHODS; One hundred and ninety-five pig corneas were preserved in Eagle's minimal essential medium with dextran and HPBCD. They were stained with trypan blue, examined using a light microscope and then reincubated. Changes in cell density and cell morphology as a function of the duration of preservation and the HPBCD concentration were evaluated. We developed a morphological classification combining the morphological aspects observed using the light microscope and the scanning electron microscope. The vitality of the endothelium was analyzed by cell separation and monolayer cultivation. RESULTS: The cell density stayed stable without significant alterations in 0.1% HPBCD, 1% HPBDC and control solutions. In 10% HPBDC, however, the endothelium showed significant loss of cells. The morphological classification revealed high-grade endothelial damage in 10% HPBDC and low-grade damage in 1% HPBCD. The changes observed in 0.1% HPBCD and control medium were comparable. The degree of alteration conformed to the results of monolayer cultivation: endothelial cells of damaged corneoscleral buttons were limited in their ability to proliferate. CONCLUSION: Severe endothelial destruction in 10% HPBCD and changes in membrane integrity at lower concentrations limit the use of HPBCD in ophthalmic solutions.

2-Hydroxypropyl-beta-cyclodextrin↗
PubMed1998

[Consequent use of the Aachen therapy concept after severe chemical burns of both eyes].

BACKGROUND: Severe chemical burn and its complications still are a serious threat to the afflicted eye, particularly in case of insufficient treatment. Rehabilitation of visual acuity can be achieved only in the minority of cases. PATIENT: We present a 49-year-old female patient, who suffered a severe chemical burn in both eyes by alcaline detergent. Visual acuity was OD 20/50, OS light perception. After directly started acute treatment as well as peritomy, peridectomy, tenon plasty and application of a PMMA contact lens a stabilization was achieved. Complete rehabilitation of visual acuity was gained by EDTA abrasion, excimer treatment, penetrating keratoplasty and cataract surgery. Last examination showed a visual acuity of 25/20 in both eyes. CONCLUSIONS: Even in severe chemical burn an optimal result can be achieved by using an adequate treatment conception. Immediate beginning of therapy is important as well as persistent and persevering application of the treatment. Repeated, if necessary daily, excisions of necrotic tissue associated with tenon plasty and application of a PMMA contact lens have special importance.

Burns, Chemical↗