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Biomedical subjects

K U Löffler

Publications and source records attributed to K U Löffler.

At least 19 recordsLinked to original sources
PubMed2006

[Neovascular glaucoma: aetiology, pathogenesis and treatment].

Neovascular glaucoma, as a typical secondary glaucoma, is due to ocular or (earlier) systemic diseases. The formation of a fibrovascular membrane on the anterior surface of the iris (rubeosis iridis) and extending into the chamber angle leads to irreversible obliteration of the outflow system, with a corresponding rise in intraocular pressure. The most frequent cause is retinal ischaemia resulting either from vascular occlusion or from diabetic alterations. The differential diagnosis must include acute angle-closure glaucoma and uncontrolled open-angle glaucoma. Treatment is aimed at eliminating the actual cause or at least reducing the risk factors (e.g. by retinal laser coagulation), or consists in cyclodestructive procedures. Medicamentous therapy comprises anti-inflammatory agents (steroids, cycloplegic agents) and substances that reduce the production of aqueous humour (carbonic anhydrase antagonists, beta blockers). In the near future, antiangiogenic medication might be another effective option. For end-stage neovascular glaucoma, the implantation of drainage devices is also discussed.

Capillaries↗
PubMed2005

Molecular imaging system for possible prediction of active retinopathy in patients with Diabetes mellitus.

OBJECTIVE: The deposition of advanced glycation end products is enhanced in Diabetes mellitus (DM) and has been linked to diabetic complications such as a microvascular disease. Glycated proteins have receptors on mononuclear blood cells (MBCs) and have been shown to generate reactive oxygen species altering gene expression and modifying cellular targets, such as endothelial cells. Retinal angiopathy is a frequently observed microvascular complication in DM-patients. Because of the central role of activated MBCs, we hypothesised a functional link between specific alterations in gene expression of MBCs, an increased activity of matrix proteases in serum, and the extent of retinal angiopathy in DM. MATERIAL AND METHODS: An appearance and proliferation index of diabetic retinopathy was evaluated in 38 DM-patients using fluorescein angiography. Alterations of gene transcription levels in MBCs were investigated using hybridisation of individual mRNA-pools to Atlas Array with a concomitant quantification of specific cDNAs by "Real-Time"-PCR. The activity of matrix metalloproteinases MMP-2 and MMP-9 in individual serum samples was measured by zymography combined with densitometric imaging system. RESULTS AND CONCLUSIONS: Hybridisation to Atlas Array of mRNA-pools isolated from MBCs revealed an enhanced expression of recoverin in DM-patients compared to the control group. "Real-Time"-PCR showed the highest recoverin levels in the DM-subgroup with a high proliferation index. MMP-2 activity was highly increased in 36% of all patients, and in 44, 44, and 19% of patients with proliferative retinopathy, advanced proliferative retinopathy, and no detectable proliferation respectively. In those 3 groups MMP-9 activity was highly increased in 56, 67, and 31% of patients respectively, and in 44% of all DM-patients. In contrast to patients with active proliferation, the simultaneous high activation of all three genes was not observed in patients without active proliferation. The ex vivo molecular imaging system developed in this work may be helpful for the prediction of active proliferative retinopathy in DM.

Diabetes Mellitus↗
PubMed1997

[Success and complications of rTPA treatment of the anterior eye segment].

Recombinant tissue plasminogen activator (rTPA) is commonly used in patients with myocardial infarction. Recently, it has also been applied intraocularly to dissolve postoperative fibrin with no serious complications being reported so far. In this study we describe our own experience with rTPA in 25 patients with persisting fibrinous membranes in the anterior segment. rTPA (Actilyse, Dr. Karl Thomae GmbH) was given in a single dose of 25 micrograms and injected into the anterior chamber via a paracentesis. We did not encounter any complications during the injection of rTPA. In 21 eyes fibrin could be reduced significantly, albeit sometimes only slowly. In 13 patients, the membrane had dissolved almost completely by the following day. In contrast, no success was observed after glaucoma surgery (2 eyes) and in chronic iritis (1 eye), or when fibrin mixed with blood was treated (1 eye). There were two (controllable) post-operative hemorrhages (rTPA after vitrectomy, and for fibrin/blood after cataract surgery). In addition, we noted 2 cases of irreversible superficial corneal clouding (rTPA after cataract surgery). We conclude that injection of rTPA can be a useful addition to steroid treatment in selective cases of persisting fibrin in the anterior segment. Long-standing membranes, however, are unlikely to be dissolved. Care should also be taken and rTPA be avoided when there is evidence of recent bleeding. Most worrying to us were the corneal complications that we cannot explain to date. With regard to the definite time correlation we feel that rTPA or one of the solution components might be the cause of this unusual feature.

Anterior Eye Segment↗
PubMed1996

[Band-like keratopathy after treatment of postoperative fibrin reaction with tissue plasminogen activator].

BACKGROUND: In recent years TPA (tissue-plasminogen activator) has been increasingly and successfully used for the treatment of severe, postoperative fibrin reaction in the anterior chamber. So far no serious side effects of this treatment have been reported. PATIENTS AND METHODS: Altogether, 32 patients received 0.2 ml solution with 20 micrograms TPA intracamerally. In 2 cases a dense corneal opacity was observed 12-24 hours after the injection of TPA which was resistant to treatment with local dexamethasone and lubricants. Therefore it was removed by superficial keratectomy. In one case the keratectomy specimen could be examined by light- and electronmicroscopy. RESULTS: In the keratectomy specimen a selective, fine-granular calcification of Bowman's membrane could be demonstrated. CONCLUSIONS: The intracameral TPA treatment for postoperative fibrin reaction can cause a rapid band keratopathy. Therefore the application of TPA should be restricted to severe therapy-resistant cases of intracameral fibrin reaction. In cases with the development of a band keratopathy EDTA-treatment is recommended.

Aged↗
PubMed1995

Sclerochoroidal granuloma in Wegener's granulomatosis simulating a uveal melanoma.

BACKGROUND: It is known that Wegener's granulomatosis may affect the eye, but macroscopically visible granulomas in patients with this condition have not yet been described. METHODS: Results of clinical, ultrasound, and histologic examination of a patient with Wegener's granulomatosis are presented. RESULTS: A sclerochoroidal granuloma in this patient simulated an uveal melanoma. It was not possible to unequivocally differentiate the lesion from a uveal melanoma on sonographic examination, but histologic examination confirmed the diagnosis of sclerochoroidal granuloma. CONCLUSION: Macroscopically visible sclerochoroidal granuloma is another facet of Wegener's granulomatosis, and in some cases may be mistaken for uveal melanoma.

Choroid↗
PubMed1995

Subretinal tumour in a patient with a limited form of Wegener's granulomatosis.

In 1939 F. Wegener published a report concerning a peculiar febrile syndrome with necrotizing inflammation of the upper respiratory tract, focal glomerulonephritis and systemic angiitis (Wegener 1939). Clinically Wegener's granulomatosis can be divided into a limited and a generalized form. We describe a patient presenting with unilateral ocular symptoms suspicious of a neoplasm, one episode of angina pectoris and general malaise without any clinical signs of upper respiratory tract involvement. Before Wegener's granulomatosis was diagnosed by a positive titre of antineutrophil cytoplasmic antibodies and open lung biopsy, immunoscintigraphy for malignant melanoma showed a false positive result. Systemic treatment with corticosteroids and cyclophosphamide resulted in an improvement of the ocular symptoms within weeks.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1995

Immunoreactivity against tau, amyloid precursor protein, and beta-amyloid in the human retina.

PURPOSE: Increased immunoreactivity (IR) of beta-amyloid and the amyloid-associated proteins tau and amyloid precursor protein (APP) in the brain have been linked to the pathogenesis of neurodegenerative disorders such as Alzheimer's disease. However, the expression of these proteins has not been investigated in the normal or diseased human retina. METHODS: Using immunohistochemical techniques, we examined the distribution and age-related changes of anti-tau-1, anti-tau-2, anti-APP, and anti-beta-amyloid IR in the human retina at various ages (n = 24), in retinitis pigmentosa (RP, n = 6), and in age-related macular degeneration (ARMD, n = 10). RESULTS: Tau-1 immunoreactivity was intense in the inner retinal layers and did not change with age or in RP. Eyes with ARMD showed less intense staining but exhibited a similar distribution. Tau-2 IR was faint and did not change with age but was mildly increased in the retinal pigment epithelium (RPE) of eyes with RP and in the retina of eyes with ARMD. APP IR was most prominent in the ganglion cell and nerve fiber layer, and it appeared to increase in ganglion cells of older persons and in RPE cells of eyes with RP and ARMD. Beta-amyloid IR was only detected focally in sub-RPE deposits in eyes from older persons. CONCLUSIONS: The proteins investigated in this study are present in the human retina. The staining pattern of tau is different from the brain, but it shows no age-related changes. The increased immunoreactivity of APP in retinal ganglion cells of older eyes and in RPE cells of eyes with RP and ARMD, as well as the patchy staining of beta-amyloid within sub-RPE deposits, might indicate a relationship of these proteins to retinal aging and possibly to retinal degeneration in RP.

Adolescent↗
PubMed1995

[Antigen pattern in choroid melanoma in correlation with immunoscintigraphy].

We have reported that the sensitivity of immunoscintigraphy in ocular melanoma is fairly low in comparison with (metastasizing) cutaneous melanoma. No significant correlation was found between the histological data for ocular melanoma and the immunoscintigraphic results. We therefore wanted to see whether we could demonstrate an antigen pattern that was different from that of cutaneous melanoma, which might explain our previous results. Our study comprised tumor tissue from 20 patients with ocular melanoma who had undergone previous immunoscintigraphic examination. Using immunohistochemical techniques, tumor immunoreactivity was investigated against 225.28S, the antibody used for immunoscintigraphy, on cryosections in 12 cases, and against anti-HMB-45, and anti-S-100 and anti-vimentin on paraffin sections in all 20 patients. In summary, there was marked immunohistochemical heterogeneity, and none of the antibodies examined showed a significant correlation with immunoscintigraphy. Even 225.28S that was used for the immunoscintigraphic examination did not retrospectively allow a predictable immunoscintigraphic outcome. When comparing our results with the literature on cutaneous melanoma we were also able to confirm differences in immunoreactivity with regard to the other antibodies. We conclude that the comparatively poor results in ocular immunoscintigraphy obtained with 225.28S are due to antigenic differences between ocular and cutaneous melanoma.

Antigens, Neoplasm↗
PubMed1994

Temporal arteritis. Comparison of histological and clinical findings.

The aim of this investigation was to correlate the clinical and histological findings in 85 consecutive patients with temporal arteritis. Particular attention was given to a possible correlation between optic nerve involvement and the presence of giant cells upon histological examination. Severe ischemia as in anterior ischemic optic neuropathy and central retinal arterial occlusion was presented in 37 patients (43%). Giant cells were definitely observed in 32 biopsy specimens (37.6%) and suspected in 11 additional specimens (13%): In 42 specimens (49.3%) no giant cells were present. Our study showed no correlation between the occurrence of severe optic nerve involvement and the histological findings with regard to giant cells. Statistical evaluation also failed to show a significant correlation between the frequency of pain and jaw claudication and the respective histological findings regarding giant cells. In the biopsy specimen of one patient, numerous eosinophilic granulocytes had infiltrated the vessel wall.

Aged↗
PubMed1994

[Immunoscintigraphy results in the comparison of ocular with cutaneous melanoma].

For several years, immunoscintigraphy (IS) using a 99mTc-labeled monoclonal antibody for tumor localization has been used as an additional tool in the diagnosis of malignant melanoma. The aim of our study was to verify previously published data with respect to our own patients and to correlate immunoscintigraphic results with histological findings. In particular, we wanted to compare the outcome of IS in ocular melanoma with that in cutaneous melanoma. We examined 28 patients (15 females, 13 males, average age 64 years) with clinically suspected ocular melanoma. IS was performed using the monoclonal antibody 225.28S (Tecnemab-K-1, Fa. Sorin/Solco), and images were obtained in a standard fashion (planar) as well as with the SPECT technique. In 16 patients, the tumor was examined afterwards histologically. The control group consisted of 102 patients with histologically proven metastasizing cutaneous melanoma who were investigated by IS in an identical fashion. In contrast to the literature published so far, we demonstrated a positive IS reaction in only 42% (and 56% in histologically proven cases, respectively) in our patients with ocular melanoma, while in patients with cutaneous melanoma, we found a sensitivity of more than 80%. In the 3 patients who turned out not to have ocular melanoma, we found one false-positive reaction (subretinal hemorrhage). No correlation was found between the various histological features of ocular melanoma and the immunoscintigraphic results. We conclude that IS using the antibody 25.28S is of limited value in patients with ocular melanoma and should only be recommended in selected cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Choroid Neoplasms↗
PubMed1993

[Synthetic skin replacement for temporary wound coverage in eyelid surgery].

BACKGROUND: Large uncovered defects of lid-skin which extend beyond the margin of the orbital rim frequently cause wound contracture and malposition of the lid. PATIENTS AND METHODS: Between April 1989 and October 1992 we have successfully used synthetic skin in severe cases of traumatic skin ablation (n = 3) and in complicated tumor surgery of the lids and of the medial canthal area (n = 14). Polyurethan foam material was used for temporary skin replacement (Epigard). RESULTS: The synthetic skin stimulated wound granulation and vascularization of the host area before final closure of the defect was achieved. No wound contracture occurred. CONCLUSION: Temporary bandage with synthetic skin is recommended if large skin defects can not be closed within 48 hours.

Adult↗
PubMed1991

Orbital squamous cell carcinoma after retinal detachment surgery.

We report on a 76-year-old patient with a squamous cell carcinoma of the left orbit. The tumour had no connection with the conjunctiva but was located at the site of an encircling band which had been inserted 13 years before. A major part of the tumour presented as a well circumscribed solid mass within the extraocular tissues next to the inferior equator, but the exenteration specimen also showed tumour extension within the adjacent choroid. Histological examination showed a well differentiated keratinising squamous cell carcinoma with numerous mitotic figures and many epithelial pearls. A thorough examination in search of a primary carcinoma of the lacrimal gland or the sinus, with invasion into the orbit, or an epithelial neoplasm elsewhere suggestive of metastatic disease into the choroid did not reveal any specific pathological findings. Thus the most probable origin of the tumour seems to be epithelium which had been misplaced during retinal detachment surgery and had subsequently undergone malignant transformation.

Aged↗
PubMed1991

Iris melanocytes on the posterior corneal surface in congenital glaucoma. A clinicopathological case report.

The histological and ultrastructural pathology of two corneas that were removed from an infant with congenital glaucoma prior to keratoplasty is described. Clinically, the glaucoma was suspected to be due to an inapparent congenital viral infection, although there was no serological proof. Macroscopic and light microscopic examination of the posterior corneal surface revealed an irregular network of heavily pigmented cells that were overlying an incomplete endothelium and a grossly thickened Descemet's membrane. By scanning and transmission electron microscopy, these melanin-laden cells exhibited the features of iris stromal melanocytes. No evidence of viral infection could be found. The possible mechanisms leading to this unusual morphology are considered and will be discussed in relation to current theories on the etiology of congenital glaucoma.

Corneal Opacity↗