Biomedical subjects

W Göttinger

Publications and source records attributed to W Göttinger.

At least 19 recordsLinked to original sources

PubMed1999

Intraocular lens power calculation after decentered photorefractive keratectomy.

A 59-year-old patient who had photorefractive keratectomy (PRK) to correct high unilateral myopia developed a progressive nuclear cataract. Phacoemulsification and intraocular lens (IOL) implantation were performed. However, determination of IOL power using automated keratometry and computerized videokeratography was not successful in this case of high axial myopia because of a decentered ablation zone, resulting in too-steep keratometric readings. Postoperative hyperopia could only be corrected by an IOL exchange. Because it may not be possible to determine the exact keratometric values for IOL calculation after PRK, subtracting the change in refraction induced by PRK from the preoperative keratometric readings might have been more accurate in this patient.

Cataract↗

PubMed1998

Substance P in proliferative vitreoretinopathy: the significance of aqueous humor levels for evolution of the disease.

PURPOSE: We detected aqueous humor levels of substance P in patients with various grades of proliferative vitreoretinopathy and with uncomplicated rhegmatogenous retinal detachment. To evaluate the significance of the concentration of substance P at the time of surgery for retinal detachment for subsequent development of proliferative vitreoretinopathy, the latter patients also underwent fundoscopic control examination. METHODS: Using a highly specific and sensitive radioimmunoassay, the content of substance P in fresh samples of aqueous humor obtained by paracentesis was determined both in cataract controls and in patients with uncomplicated rhegmatogenous retinal detachment and with various grades of proliferative vitreoretinopathy. Retinal detachment patients underwent fundoscopic control examination 6 months after surgical reattachment. RESULTS: The mean concentration of substance P in cataract controls was 40.3 (+22.4) fmol/mg protein, in the retinal detachment group 61.9 (+/-13.9) fmol/mg protein and in proliferative vitreoretinopathy 335.2 (+/-24.8) fmol/mg protein, but no correlation between levels of the peptide and various grades of the disease was observed. Already at surgery for retinal detachment three in four patients who developed proliferative vitreoretinopathy presented with levels of substance P in the range of the disease. CONCLUSION: The concentration of substance P in aqueous humor is significantly high in patients with proliferative vitreoretinopathy in whom surgery is indicated. Furthermore, elevation of the peptide in retinal detachment that originates most obviously from a neurogenic mechanism may indicate initiation of processes associated with proliferative vitreoretinopathy, thus representing an indicator of significant risk for evolution of the disease at a very early time.

Adult↗

PubMed1998

[Progressive corneal ectasia after laser in situ keratomileusis (LASIK)].

BACKGROUND: LASIK (Laser in situ keratomileusis) is used in refractive surgery especially for correction of higher degrees of myopia. Preservation of Bowman's layer as well as less postoperative pain and the slight to absent subepithelial haze are regarded as advantages compared to photorefractive keratectomy (PRK). However, numerous serious complications have been described in the literature. PATIENTS AND METHODS: LASIK treatment was performed elsewhere in two patients to treat myopia or myopic astigmatism between -6 and -9 diopters (D). An astigmatism of -6 D was corrected with the LASIK method in another patient with keratoconus. Progressive corneal ectasia of up to seven diopters occurred in all four eyes within a few months. CONCLUSION: Corneal ectasia can occur after LASIK even in low degrees of myopia of less than ten diopters. Recently, -12 D has been specified as the upper limit for this technique. It is especially important to rule out an early keratoconus or a forme fruste of keratoconus preoperatively since keratectasia with particularly rapid progression can occur in such cases: we would like to designate this as "malignant keratoconus".

Adult↗

PubMed1997

Influence of viral infection on expression of cell surface antigens in human retinal pigment epithelial cells.

BACKGROUND: Subacute viral infection is known to change the phenotype of infected cells, thereby causing immune-mediated tissue damage. The aim of this study was to investigate the expression of different cell surface molecules on human retinal pigment epithelial cells (RPEC) following viral infection, with special emphasis on those having immune-regulatory functions. METHODS: Cultured RPEC were infected with cytomegalovirus (CMV), coxsackie-virus B3 (CVB) or herpes simplex virus type I (HSV). Double-staining fluorescence technique was used for visualization of virus infection and cell surface markers in the same cells by laser microscopy. RESULTS: CMV downregulated MHC class I antigens on RPEC, whereas CVB and HSV did not alter MHC class I antigen expression. No induction of class II antigens was observed in RPEC infected with CVB, HSV or CMV. The intercellular adhesion molecule ICAM-1 (CD54) was strongly expressed in uninfected RPEC, and a slight increase was observed after virus infection. Vascular cell adhesion molecule 1 (VCAM-1) was expressed in low amounts in both uninfected and infected RPEC. No expression of intercellular adhesion molecule 2 (ICAM-2), E-selectin ELAM-1 or lymphocyte-function-associated antigen 1 (LFA-1) was observed on RPEC before or after virus infection. CONCLUSION: Downmodulation of immune-regulating cell surface antigens has been suggested to provide a means of long-term survival of viruses in the infected cell, favoring establishment of persistent infection. Our observation in cultured human RPEC indicates that this mechanism might indeed contribute to the development of disease affecting retinal tissue.

Animals↗

PubMed1996

Susceptibility of human retinal pigment epithelial cells to different viruses.

BACKGROUND: Different viruses have been reported to be involved in retinal diseases in animal systems. In humans, herpes simplex virus and cytomegalovirus have been found to cause retinal disease. Most of the studied viruses are neurotropic. In this study, the in vitro susceptibility of human retinal pigment epithelial cells (RPEC) to representative members of different groups of human pathogenic viruses was investigated. METHODS: Early cultures of RPE C - after two or three passages - were infected with the following viruses: herpes simplex virus (HSV) type 1, human herpesvirus 6 (HHV-6), Epstein-Barr virus (EBV), cytomegalovirus (CMV), adenovirus types 1 and 7, measles virus, parainfluenza virus and coxsackie virus B3. RESULTS: Cultures of RPE C could be infected with neurotropic viruses like HSV or measles virus as well as with typical respiratory viruses like parainfluenza or adenoviruses. Coxsackievirus, an enterovirus, replicated as well as human CMV, whereas EBV and HHV-6, two lymphotropic viruses, failed to infect RPE. CONCLUSION: These findings suggest that a variety of viruses, including those causing rather common illnesses, might be capable of inducing retinal lesions under certain circumstances due to haematogenous spread during the course of viraemia.

Antibodies, Monoclonal↗

PubMed1996

Cost-benefit analysis of diabetic eye disease.

Diabetic retinopathy is the main cause of blindness in adults 25-74 years of age in Western countries. At 100% diagnosability and 100% treatability, with laser photocoagulation vision can be retained in at least one eye in 73% of patients with proliferative retinopathy and in 67% of patients with diabetic maculopathy. The cost-benefit analysis draws a comparison of the costs incurred through benefits granted to a blind diabetic and those incurred through proper screening, examination and treatment to avoid blindness as much as possible. These calculations are valid for the State of Tyrol in Austria. The anticipated annual costs for blindness are thus ATS 19,000,000, of which ATS 14,600,000 could be avoided through an optimal screening, examination and therapy program. The maximum costs for examination and therapy amount to ATS 10,700,000, thus giving a minimum saving of ATS 3,900,000 in favor of preventive medicine.

Adult↗

PubMed1994

Fibroblast growth-promoting activity in proliferative vitreoretinopathy: antagonism by acetylsalicylic acid.

Proliferative vitreoretinopathy is a severe reactive process which leads to the formation of cellular membranes on the surface of the retina and in the vitreous. We determined the fibroblast growth-promoting activity of intraocular fluid from patients suffering from proliferative vitreoretinopathy, retinal detachment or cataract and further evaluated the effect of acetylsalicylic acid on growth-stimulated fibroblasts. The results demonstrated a significant enhancement of growth-promoting activity of intraocular fluid in proliferative vitreoretinopathy as compared to that of control samples. We showed that the augmented growth-promoting activity of intraocular fluid in proliferative vitreoretinopathy was significantly antagonized by inhibition of cyclooxygenase with acetylsalicylic acid (ID50 approximately 5 microM). In contrast, no significant effect was seen in corresponding control experiments. The findings suggest that metabolites of the cyclooxygenase pathway are involved in the regulation of enhanced intraocular fluid-induced fibroblast proliferation in proliferative vitreoretinopathy and that acetylsalicylic acid might be useful as an antiproliferative agent in intraocular fibrogenesis.

Adult↗

PubMed1994

Hereditary vitreoretinal dystrophy associated with peripheral neuropathy.

Autosomal dominant inherited vitreoretinal dystrophy has been reported to occur as isolated ocular disease (Wagner's disease) or in combination with systemic manifestations (e.g., Stickler's syndrome). We examined five members of one family (three generations) and found vitreoretinal dystrophy and non-ocular signs in a mother and her two children. In the mother we also observed tractional detachment of the macula. In addition to routine ophthalmological examinations, we performed electrophysiological tests (ERG, EOG), adaptometry and magnetic resonance imaging of the head. Neurological examination revealed peripheral neuropathy in the mother and her children. We had no evidence that the neuropathy had a toxic or metabolic origin, and other genetically determined neuropathies were unlikely based on the clinical picture, MRI, and laboratory tests. Therefore, the neuropathy might be either a hitherto unrecognized feature of a variant of Stickler's syndrome or part of a yet unclassified hereditary vitreoretinal dystrophy with systemic involvement.

Adolescent↗

PubMed1994

Different concentrations of vasoactive intestinal polypeptide in aqueous humor of patients with proliferative vitreoretinopathy and cataract patients.

The pathophysiological events leading to cellular proliferation in proliferative vitreoretinopathy are largely unknown. An involvement of neuropeptides in that disease has recently been discussed, as substance P was found to be highly enriched in the intraocular fluid of patients with proliferative vitreoretinopathy. In the present study, aqueous humor was analyzed for another neuropeptide, vasoactive intestinal polypeptide. Radioimmunoassay revealed significantly increased levels of that polypeptide in the aqueous humor of patients with proliferative vitreoretinopathy as compared with cataract patients who served as controls. As vasoactive intestinal polypeptide contributes to the environment of the retinal pigment epithelial cell layer and induces proliferation of these cells in vitro, this peptide may be involved in the pathogenetic mechanisms leading to cellular proliferation in proliferative vitreoretinopathy.

Aqueous Humor↗

PubMed1993

[Leukocyte adhesion molecules in chronic inflammatory diseases of the cornea].

Using immunohistochemical techniques, we investigated the expression of leukocyte adhesion molecules-intercellular adhesion molecule-1 (ICAM-1), E-selectin (endothelial leukocyte adhesion molecule-1), and vascular cell adhesion molecule-1 (VCAM-1)--in various chronic inflammatory corneal diseases of different etiology. ICAM-1 was focally expressed on epithelial cells and showed an increased expression, on keratocytes, corneal endothelial cells, and vascular endothelial cells. E-selectin was present on vascular endothelial cells of several corneas, while VCAM-1 was found particularly on macrophages and only sporadically on vascular endothelial cells. Our results suggest that ICAM-1, E-selectin, and VCAM-1 may be involved in the pathogenesis of various chronic inflammatory corneal diseases, particularly in the selective recruitment of different leukocyte populations.

Adult↗

PubMed1993

Leukocyte adhesion molecules in diseased corneas.

PURPOSE: To help define the possible role of leukocyte adhesion molecules in the pathogenesis of corneal inflammation, we investigated the presence and distribution of intercellular adhesion molecule-1 (ICAM-1), E-selectin (endothelial leukocyte adhesion molecule-1 [ELAM-1]), and vascular cell adhesion molecule-1 (VCAM-1) in various corneal diseases. METHODS: Monoclonal antibodies (mAbs) to ICAM-1, E-selectin, and VCAM-1 were used for immunohistochemical staining of frozen sections of 55 human corneas with various inflammatory and degenerative diseases. In addition, we used a panel of mAbs to characterize the composition and density of the inflammatory infiltrates in the diseased corneas. RESULTS: ICAM-1 was focally expressed on epithelial cells in corneas with chronic allograft rejection, herpetic stromal keratitis, zoster keratitis, chemical burns, atopic keratitis, fungal keratitis, and bacterial keratitis. Furthermore, the expression of ICAM-1 was focally increased on keratocytes, corneal endothelial cells, and vascular endothelial cells (particularly at the site of lymphoid infiltration) in these corneas. E-selectin was present on vascular endothelial cells of limbal vessels in corneas with bacterial keratitis and also on endothelial cells of vessels in the stroma of several corneas with chronic inflammatory diseases. VCAM-1 was focally expressed on endothelial cells of vessels in the stroma of some corneas with chronic allograft rejection, herpetic stromal keratitis, chemical burns, and atopic keratitis. Interestingly, VCAM-1 was also found on inflammatory cells of the macrophage-monocyte lineage in inflamed corneas. CONCLUSIONS: Our results demonstrate that ICAM-1, E-selectin, and VCAM-1 are expressed in diseased corneas, often in areas of inflammation.

Adult↗

PubMed1992

[Semiconducting lasers for the treatment of vascular retinopathy].

Clinical photocoagulation was performed successfully in 18 eyes with retinal vascular disease. In all cases semiconductor laser was used emitting wave lengths from 780 to 840 nm. Energy for visible coagulation edema was 400 up to 1,200 mW, time between 0.2 and 1 s. In 3 cases using endolaser, acute retinal traction during light exposition was seen; retinal hemorrhages occurred in no patient. Four patients complained of moderate to marked pain compared to argon laser treatment. In all cases visible marked retinal scars of therapeutical range were observed.

Adult↗

PubMed1991

T6-positive Langerhans cells in diseased corneas.

Langerhans cells (LC) in normal human corneas (with the exception of newborns) lack thymocyte antigen T6, a highly specific marker for noncorneal LC. Because corneal LC could not be induced to express T6 antigen when cultured with various cytokines including interleukin-1 (shown to modulate T6 expression on gingival LC), some authors assume that corneal LC may represent a distinct LC subpopulation that is innately inactive. In this study, 62 corneas from patients with various corneal diseases were investigated for the presence of T6 and histocompatibility antigen HLA-DR on LC in the central and pericentral epithelium. Both T6- and HLA-DR-positive LC at a high density similar to that observed in normal epidermis could be detected in the epithelium of five corneas with epidermalization after alkali burns. Furthermore T6- and HLA-DR-positive LC at smaller densities also were detected in corneas from patients with chronic herpetic stromal keratitis, zoster keratitis, chronic allograft rejection, and bacterial corneal ulcers. Although the functional significance of T6 expression on corneal LC remains to be determined, the induction of T6 antigen on corneal LC may represent an important event for the antigen-presenting function of these cells in various corneal diseases including corneal allograft rejection.

Alkalies↗

PubMed1990

Analysis of human tear proteins by different high-performance liquid chromatographic techniques.

A comparison of the efficiencies of hydrophobic interaction chromatography, ion-exchange chromatography, reversed-phase chromatography and gel permeation chromatography in the separation of tear proteins was made using a variety of different buffers. Separation of immunoglobulins, lactoferrin, albumin, PMFA (protein migrating faster than albumin) and lysozyme was accomplished by gel permeation chromatography in less than 30 min using a TSK-type SW3000 column equilibrated with ammonium acetate buffer (pH 4.1) with a high reproducibility. When gel permeation chromatography was used as a completely automated diagnostic method, only minute volumes (1.0 microliter) of tear samples were necessary for the quantitative analysis of proteins. The other three methods proved to be more suitable for the preparation of individual tear proteins but were less suitable for their quantitation.

Albumins↗

PubMed1990

Effective methods for the investigation of human tear film proteins and lipids.

The investigation of human tear film proteins and lipids is of value for the elucidation of contact lens incompatibilities, tear film instabilities, dry eye syndrome and various other eye diseases. Improved efficient methods for the investigation of human tear film proteins and lipids are presented in this paper. Tear proteins were examined by ultrathin sodium dodecyl sulfate-polyacrylamide gel electrophoresis, celluloacetate gel, isoelectric focusing, and high-performance liquid chromatography. The methods differ in sensitivity, resolution, convenience and reproducibility. Tear lipids were examined by high-performance thin-layer chromatography, and good separation into the major lipid classes was achieved. With this method it is possible to examine the lipids present in tears of an individual subject and not just in pools made up from the tears of several persons.

Chromatography, High Pressure Liquid↗

PubMed1990

[Data processing at the special diabetes ambulatory center of the Innsbruck Ophthalmology University Clinic--electronic data processing in ophthalmology].

During the last 2 years, a personal computer in the special diabetes department of Innsbruck University Eye Hospital has not merely facilitated statistical analysis; without the PC such analysis would not have been possible. Logistically, the most important function is data acquisition, because the system only works if all data are entered. In addition to data processing, word processing, statistical analyses, and chart processing using graphics software are all done on the PC. The system is currently being developed further to include on-line access to literature databases via Datex-P and additional workstations. After 3 years of experience with the PC it is difficult to imagine doing scientific work without it.

Ambulatory Care↗

PubMed1990

[Incidence and function of Langerhans cells in various corneal diseases].

Using immunohistochemical techniques, we investigated the distribution and frequency of Langerhans cells in corneal buttons obtained from patients who underwent corneal transplantation because of various corneal diseases. The frequency of these dendritic cells was similar to that in the normal epidermis in corneas with epidermalization after severe alkali burns. Numerous Langerhans cells, albeit in smaller numbers, were also present in the central corneal epithelium of patients with keratitis due to infection with herpes simplex virus, keratitis due to herpes zoster virus, bacterial corneal ulcers, corneal scars, corneal ulcers associated with rheumatoid arthritis, and patients with chronic corneal allograft reactions. The presence and persistence of Langerhans cells in diseased corneas may account for, at least in part, a breakdown of corneal immune privilege with a higher rate of rejection episodes after corneal transplantation. Furthermore, it is probable that Langerhans cells as potent antigen-presenting cells may also play an important role in the initiation and the progression of immune responses in various inflammatory corneal diseases.

Cell Count↗

PubMed1989

Studies of the mechanism of tolerance induced by short-term immunosuppression with cyclosporine in high-risk corneal allograft recipients. I. Analysis of CTL precursor frequencies.

Transplantation of unmatched allogeneic corneas into highly vascularized recipient eyes under the cover of short-term immunosuppression with cyclosporine enables permanent engraftment. The aim of this study was to further elucidate the mechanism(s) underlying this tolerant state. In eight "high-risk" cornea recipients the clone sizes of donor-specific and third-party reactive cytotoxic T cell precursors were assessed by limiting dilution analyses before and at three and six months after transplantation. Acquired allograft tolerance in these patients was not accompanied by clonal reduction of donor-specific CTL-p, whereas in the case of an irreversible rejection the donor-specific CTL pool size was significantly enlarged. This donor-specific CTL-p increase could already be seen two months before clinical manifestation. These patterns differed from that of tolerant renal transplant patients, in whom marked and donor-specific reduction of CTL-p was observed. During rejection identical patterns with increasing donor-specific CTL-p frequencies were seen in both groups of patients. We conclude that induction of tolerance by short-term CsA to unmatched cornea grafts is not caused by clonal reduction of the effector precursor cell pool.

Adult↗