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Anselm Kampik

Publications and source records attributed to Anselm Kampik.

At least 73 records · Page 4Linked to original sources
PubMed2003

Intravenous treatment of experimental Staphylococcus aureus endophthalmitis: imipenem versus the combination of ceftazidime and amikacin.

BACKGROUND: To compare the efficacy of intravenous (IV) imipenem (IPM) and a combination of IV ceftazidime (CAZ) and amikacin (AN) in the treatment of Staphylococcus aureus endophthalmitis in a rabbit model. METHODS: Right eyes of 60 albino rabbits were injected with 1000 colony-forming units of S. aureus intravitreally. After 24 h, treatment with either IV IPM (37.5 mg/kg) every 8 h ( n=18) or IV CAZ (50 mg/kg) and AN (10 mg/kg) every 8 hours ( n=18) was begun and continued until the animals were killed at the indicated timepoints; 24 control animals received no treatment. The concentration of bacteria in the vitreous from six animals per group was determined microbiologically on days 2, 3, and 5 after infection, and histologic examination was performed on all eyes. RESULTS: The number of eyes with positive cultures on day 5 was lower in the group that received IV IPM (2/6) compared with the IV CAZ/AN group (4/6) and the control group (6/6). For the culture-positive eyes, the bacterial concentrations were significantly lower for the IV IPM group compared with the IV CAZ/AN group on days 2 and 5 ( P<0.05 and P<0.0065, respectively), but not on day 3 ( P <0.8. Bacterial counts in both treatment groups were significantly lower than in the control group ( P<0.005). Eyes in all groups, however, showed severe intraocular inflammation. CONCLUSIONS: IV IPM is more effective than is IV CAZ/AN in reducing the number of bacteria in an animal model of S.aureus endophthalmitis.

Amikacin↗
PubMed2003

Functional outcome of macular hole surgery with and without indocyanine green-assisted peeling of the internal limiting membrane.

PURPOSE: To describe the impact of indocyanine green (ICG) staining of the internal limiting membrane (ILM) on the functional outcome of anatomically successful macular hole surgery by comparing consecutive patient series with and without ILM staining. METHODS: Eighteen consecutive patients who had undergone ICG-assisted vitrectomy (0.05%) for idiopathic macular hole were retrospectively analysed (visual acuity, gain in lines, Goldmann perimetry) and compared with two consecutive series of patients who had undergone macular hole surgery without the use of ICG immediately before (n=22) and after (n=17) the introduction of ICG in our institution. The osmolarity of the ICG solution applied was 275 mosmol, pH was 7.5. RESULTS: Although there was no statistically significant difference in duration of preoperative symptoms (P>0.3) and preoperative visual acuity (P>0.5), the functional outcome in patients after ICG-assisted vitrectomy was significantly lower (P<0.001 for visual acuity). The incidence of visual field defects was 50% (9/18) in patients after ICG application. CONCLUSION: Our findings suggest potential damage to the neurosensory retina in association with the intraoperative administration of the ICG solution. Whether this is caused by toxic effects of the dye itself, mechanical trauma to the retina or other mechanisms remains unknown.

Aged↗
PubMed2003

Evaluation of minimally invasive therapies and rationale for a prospective randomized trial to evaluate selective intra-arterial lysis for clinically complete central retinal artery occlusion.

OBJECTIVES: To determine the effect of commonly used minimally invasive treatments for clinically complete nonarteritic central retinal artery occlusion (CRAO) and design a prospective randomized trial to evaluate selective intra-arterial lysis for this condition. METHODS: In this retrospective noncomparative case series, all medical records of patients with a diagnosis of CRAO treated at the Department of Ophthalmology, Ludwig-Maximilians-Universität, Munich, Germany, from 1994 through 1999 were reviewed for treatments administered and course of visual acuity. MAIN OUTCOME MEASURES: Best-corrected visual acuity (BCVA) at initial and last visit. RESULTS: We identified 102 patient medical records; 71 were suitable for further analysis. Forty-four (62%) of the 71 patients included were treated with oral acetylsalicylate; 44 (62%), with oral acetazolamide; 32 (45%), with ocular massage; 22 (31%), with isovolemic hemodilution; 19 (27%), with oral pentoxifylline; 8 (11%), with topical beta-blocker; 6 (8%), with paracentesis of the anterior chamber; 4 (6%), with subcutaneous heparin. A mean +/- SD number of treatments of 2.5 +/- 1.4 was administered per patient, and BCVA increased by a mean +/- SD number of Snellen lines of 0.7 +/- 2.8. The BCVA in 11 patients (15%) increased by 3 or more lines. Multivariate stepwise regression did not reveal any single or combination treatment as a significant factor for improvement in BCVA. Patient age and duration of visual impairment before initial examination were not significant predictors of final BCVA. CONCLUSIONS: Commonly used minimally invasive treatments of CRAO do not improve the natural course of the disease. A prospective trial by the European Assessment Group for Lysis in the Eye is under way to evaluate selective intra-arterial lysis, and in this trial some of these minimally invasive treatments are used in the control group.

Acetazolamide↗
PubMed2003

The effect of indocyanine-green on functional outcome of macular pucker surgery.

PURPOSE: To compare functional results after surgery for macular pucker either with or without indocyanine-green staining of the internal limiting membrane (ILM) and to evaluate the ultrastructure of the tissue removed. DESIGN: Retrospective analysis of two successive, consecutive, interventional case series. METHODS: Functional outcome (visual acuity, Goldmann perimetry) of 48 eyes of 48 consecutive patients with (group 1, n = 20) or without (group 2, n = 28) intraoperative use of indocyanine-green (ICG) was retrospectively analyzed. For statistical analysis, best-corrected visual acuity measured at the last presentation was considered. Only patients with an idiopathic macular pucker were included. Surgery consisted of three-port pars plana vitrectomy, and removal of epiretinal tissue and the ILM in a second step. Commercially available ICG with a concentration of.05% and an osmolarity of 275 mOsm was used to stain the ILM. The surgical technique used for both groups was identical, except the use of ICG. Epiretinal tissue of all eyes was harvested and prepared for ultrastructural analysis using light and electron microscopy. RESULTS: Follow-up time was 8.5 months in group 1 and 5.4 months in group 2. Whereas patients operated on without ICG experienced a significant improvement of median best-corrected visual acuity from 20/63 (range, 20/400 to 20/32) preoperatively to 20/40 (range, 20/200 to 20/25) postoperatively (P < .001), median best-corrected visual acuity remained 20/63 before (range, 20/200 to 20/63) and after (range, 20/400 to 20/20) (P > .9) ICG-assisted peeling. There was a statistically significant difference (P = .013) in best-corrected postoperative visual acuity of patients with and without the use of ICG. An improvement of vision was noted in 86% of patients without and 55% of patients with ICG-assisted surgery. Thirty-five percent of patients after ICG application presented with a deterioration of visual acuity. Furthermore, we observed large visual field defects in 7 of 20 patients after ILM staining. No visual field defects were noted after conventional peeling. Histologic analysis revealed clear differences between the two groups concerning the amount of cellular elements adjacent to the retinal surface of the ILM: There was more cellular debris visible in specimens after ICG application during surgery. Additionally, in contrast to surgery without ILM staining, epiretinal cells had ruptured and lost their cellular integrity after ICG-assisted vitrectomy. CONCLUSIONS: Indocyanine green-assisted surgery for macular pucker might have an adverse effect on functional outcome. Although there were obvious differences in the ultrastructure of tissue removed during surgery, our observations cannot be explained by histologic analysis alone. Other, so far unknown mechanisms of action must be considered.

Adult↗
PubMed2003

Indocyanine green for successful repair of a long-standing macular hole.

PURPOSE: To report on the successful closure of a persistent chronic macular hole using indocyanine green (ICG) during the second surgical approach. DESIGN: Interventional case report. METHODS: A patient with a long standing macular hole (18 years) underwent pars plana vitrectomy with peeling of the internal limiting membrane (ILM). While no dye was used during the first operation, ICG (0.05%, Pulsion) was applied during the second procedure. The light source was turned off immediately after the ICG application until the dye was washed out after a period of 15 seconds. Tissue harvested during the second surgical approach was prepared for electron microscopy. RESULTS: After the failure of the first operation, areas of incomplete ILM peeling could be stained using ICG and a thorough ILM removal was achieved. Postoperatively, the macular hole was closed, as confirmed by optical coherence tomography. Visual acuity increased from 20/200 to 20/50. No visual field defects were seen postoperatively. There were only few cellular elements adherent to the retinal surface of the ILM as seen during electron microscopy. CONCLUSION: In cases where tractional forces due to incomplete ILM removal are considered responsible for the persistence of a macular hole, ICG is useful to identify areas of unpeeled ILM. Under certain safety precautions no adverse effect on functional outcome was seen.

Aged↗
PubMed2003

Proposed international clinical diabetic retinopathy and diabetic macular edema disease severity scales.

PURPOSE: To develop consensus regarding clinical disease severity classification systems for diabetic retinopathy and diabetic macular edema that can be used around the world, and to improve communication and coordination of care among physicians who care for patients with diabetes. DESIGN: Report regarding the development of clinical diabetic retinopathy disease severity scales. PARTICIPANTS: A group of 31 individuals from 16 countries, representing comprehensive ophthalmology, retina subspecialties, endocrinology, and epidemiology. METHODS: An initial clinical classification system, based on the Early Treatment Diabetic Retinopathy Study and the Wisconsin Epidemiologic Study of Diabetic Retinopathy publications, was circulated to the group in advance of a workshop. Each member reviewed this using e-mail, and a modified Delphi system was used to stratify responses. At a later workshop, separate systems for diabetic retinopathy and macular edema were developed. These were then reevaluated by group members, and the modified Delphi system was again used to measure degrees of agreement. MAIN OUTCOME MEASURES: Consensus regarding specific classification systems was achieved. RESULTS: A five-stage disease severity classification for diabetic retinopathy includes three stages of low risk, a fourth stage of severe nonproliferative retinopathy, and a fifth stage of proliferative retinopathy. Diabetic macular edema is classified as apparently present or apparently absent. If training and equipment allow the screener to make a valid decision, macular edema is further categorized as a function of its distance from the central macula. CONCLUSIONS: There seems to be a genuine need for consistent international clinical classification systems for diabetic retinopathy and diabetic macular edema that are supported with solid evidence. The proposed clinical classification systems provide a means of appropriately categorizing diabetic retinopathy and macular edema. It is hoped that these systems will be valuable in improving both screening of individuals with diabetes and communication and discussion among individuals caring for these patients.

Diabetic Retinopathy↗
PubMed2003

RPE cell transplants to non-immune-privileged sites of the eye transform into fibroblast-like cells.

PURPOSE: In vitreoretinopathy membranes and in vitro, RPE cells lose pigment and transform into fibroblast-like cells. The purpose of this study was to investigate whether the immune privileged status of different eye compartments influence morphological changes of adult RPE cell transplants. METHODS: RPE cells from adult C57BL/6 mice were transplanted either intravitreally (n = 31), subretinally (n = 28), intrachoroidally (n = 21) or subconjunctivally (n = 33) into one eye of BALB/c mice and intravitreally (n = 5) into rd-mice with loss of ACAID (14-16 months). Eyes were enucleated after 1, 2, 4 and 6 weeks, and transplants investigated by light (n = 128) and electron microscopy (n = 40). RESULTS: Allogeneic adult RPE cells lost pigment and transformed into spindle shaped cells when injected into the recipient subconjunctiva. In vitreous or subretinal space they remained rounded and pigmented. In the choroid, they were spindle shaped but contained more pigment and were larger than those in the conjunctiva. No inflammatory reaction in the uvea or development of epiretinal membranes was seen. In contrast, in all rd-mice an inflammation of the uvea and development of epiretinal membranes was observed. CONCLUSIONS: Our findings suggest that changes in the environment of RPE in single cell suspension dictate the phenotype the cells adopt. It is possible that changes in microenvironmental factors contribute to the pathogenesis of proliferative vitreoretinal (PVR) membranes.

Animals↗
PubMed2003

Optical coherence tomography for the detection of laser in situ keratomileusis in donor corneas.

PURPOSE: In 2001, more than one million laser in situ keratomileusis (LASIK) procedures were performed worldwide. Considering the increasing number of refractive procedures, eye banks will be increasingly confronted with the problem of how to identify those donors with prior refractive surgery. To date, efficient screening methods to identify LASIK surgery in donor eyes have not been established. Therefore, the purpose of the current study was to determine whether optical coherence tomography (OCT) can be used to detect the presence of LASIK-induced changes in human corneas. METHODS: Laser in situ keratomileusis was performed on 20 organ-cultured human cornea disks. The excimer laser ablation performed ranged from 0 to 12 diopters. The corneas were maintained in culture, and the visibility of flap-stromal interface by OCT was assessed up to 6 months after the LASIK procedure. Additionally, two donor corneas with the history of LASIK treatment before death were screened for structural changes. RESULTS: Optical coherence tomography scans were able to detect the interface between the corneal flap and the residual stromal tissue in all corneas and at all examined time intervals. There were no differences in signal intensity among the different depths of ablation. The relative signal intensity of the interface compared with the averaged stromal intensity ranged from 2.1 to 6.0. In both donor corneas with suspected prior LASIK surgery, OCT scanning showed the characteristic stromal interface as found in the in vitro model. CONCLUSIONS: Corneal examination by OCT could be an appropriate technique for eye banks to screen donor corneas for prior LASIK surgery.

Adult↗
PubMed2003

Tissue transglutaminase as a modifying enzyme of the extracellular matrix in PVR membranes.

PURPOSE: Proliferative vitreoretinopathy (PVR) is characterized by the development of epi- and subretinal fibrocellular membranes containing modified retinal pigment epithelial (RPE) cells among others. In the present study, the role of transglutaminases in accumulation of extracellular matrix (ECM) proteins in these membranes was investigated. Transglutaminases are enzymes capable of cross-linking ECM proteins to proteolysis-resistant complexes. METHODS: PVR membranes were incubated with dansyl-cadaverine to demonstrate active transglutaminase. Localization of tissue transglutaminase (tTgase), its reaction product epsilon-(gamma-glutamyl)-lysine, and fibronectin was investigated immunohistochemically. Colocalization was studied with a confocal laser scanning microscope. PVR membranes were also analyzed by RT-PCR for the presence of tTgase mRNA. In vitro, RPE cells were treated with transforming growth factor-beta2 (TGF-beta2), basic fibroblast growth factor, interleukin-6, and interleukin-1beta. Their effect was studied using immunohistochemistry and Northern and Western blot analyses. RESULTS: Transglutaminase activity and expression of tTgase were present in all PVR membranes. Staining was most prominent at the rim of the membranes. The enzyme was colocalized with epsilon-(gamma-glutamyl)-lysine and fibronectin. No staining differences were found between epi- and subretinal membranes. Although native RPE cells contained only a basal level of tTgase mRNA, the expression and activity of tTgase was increased under culture conditions and further stimulated by TGF-beta2 treatment. CONCLUSIONS: The findings demonstrate that in PVR membranes tTgase is present and functionally active. The amount and activity of this enzyme appears to be related to the differentiation state of the RPE cells and their stimulation by TGF-beta2, a growth factor known to be increased in the vitreous of PVR. Intervention at this pathway may open a new approach for PVR prevention and therapy.

Adolescent↗
PubMed2003

Retinal damage from indocyanine green in experimental macular surgery.

PURPOSE: Previous work has shown that indocyanine green (ICG)-assisted peeling of the inner limiting membrane (ILM) may cause retinal damage. In this study, a toxic and a photodynamic effect of ICG at the vitreoretinal interface was assumed. METHODS: Ten human donor eyes were hemisected, and 0.05 mL of 0.05% ICG was poured over the trephined macula in eight eyes. After 1 minute, the dye was drained by irrigation. The macula in each of two eyes was illuminated for 3 minutes with wavelengths of 380 to 760, 380 to 620, or 620 to 760 nm. Two eyes were treated with ICG only, and two eyes were illuminated only. Retinal specimens from the macula and the untreated retina were processed for light and electron microscopy. The irradiance of the light source and the absorption properties of ICG were measured. RESULTS: Exposure of the ICG-stained ILM to wavelengths beyond 620 nm resulted in severe damage to the inner retina, including loss of ILM, cellular disorganization, and fragmentation of the cytoplasm. ICG staining alone or in combination with wavelengths of 380 to 620 nm disclosed rupture of Müller cells with detachment of the ILM, but no other cellular disorganization. Eyes subjected to illumination only showed no abnormalities. CONCLUSIONS: The spectral absorption properties of ICG may account for a possible photodynamic effect of ICG at the vitreoretinal interface. ICG alone induces ILM detachment and disruption of Müller cells even without intentional peeling of the membrane. It is assumed that accumulation of the dye at the vitreomacular interface may enhance the concentration and osmolarity of ICG at the retina beyond intravitreous values and critical limits.

Adolescent↗
PubMed2003

Alkylphosphocholines inhibit proliferation of human retinal pigment epithelial cells.

PURPOSE: To investigate the effect and mechanism of action of alkylphosphocholines (APCs) on proliferation of human retinal pigment epithelium (RPE) cells and RPE-mediated collagen matrix contraction in vitro. METHODS: Cultured RPE cells of five human donors were treated with four APCs in the presence of fetal calf serum. Proliferation was assessed by the tetrazolium dye-reduction (MTT) assay and by counting the number of cells dividing in culture. The effect of APCs on RPE-mediated matrix contraction was determined in three-dimensional collagen gels. Cell viability was tested by the trypan blue exclusion assay. As a possible mechanism of APC action, protein kinase C (PKC) activity was quantified by scintillation counting of (32)P-labeled phosphate transferred to a PKC-specific substrate. RESULTS: All APCs inhibited RPE proliferation and RPE-mediated collagen matrix contraction in a dose-dependent manner in vitro. The antiproliferative and anticontractile effect of APCs increased with elongation of the fatty acid chain beyond C20. IC(50)s of all APCs varied between 8.5 micro M (erucyl-phosphocholine, C22:1-PC), 9.0 micro M (Z)-12-heneicosenyl-phosphocholine, C21:1-PC), 11.0 micro M (Z)-10-eicosenyl-phosphocholine, C20:1-PC), and 26.5 micro M (oleyl-phosphocholine, C18:1-PC). Trypan blue staining revealed a toxicity below 5% for all APCs within the concentration interval tested. PKC activity was significantly reduced by all four APCs, with C22:1-PC being the most effective. CONCLUSIONS: APCs inhibit proliferation of RPE cells and RPE-mediated matrix contraction in vitro at nontoxic concentrations. This effect seems to be exerted through inhibition of PKC activity. Therefore, APCs are promising candidates for treatment of RPE-mediated proliferative processes such as proliferative vitreoretinopathy.

Adolescent↗
PubMed2003

Comparative proteome analysis of native differentiated and cultured dedifferentiated human RPE cells.

PURPOSE: Dedifferentiation of retinal pigment epithelial (RPE) cells is a crucial event in the pathogenesis of proliferative vitreoretinopathy (PVR). This study was designed to improve the understanding of RPE cell dedifferentiation in vitro. The protein expression pattern of native differentiated RPE cells was compared with that of cultured, thereby dedifferentiated, RPE cells. METHODS: Differentiated native human RPE cells and monolayers of dedifferentiated cultured primary human RPE cells were processed for two-dimensional (2-D) electrophoresis. Total cellular proteins were separated by isoelectric focusing using immobilized pH gradients (IPG 3-10) and electrophoresis on 9% to 15% gradient polyacrylamide gels. Proteins were visualized by silver staining. Silver-stained gel spots were excised, digested in situ, and analyzed by matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectroscopy (MS). The resultant peptide mass fingerprints were searched against the public domain NCBInr, MSDB, and EnsemblC databases to identify the respective proteins. RESULTS: One hundred seventy nine protein spots were analyzed and classified into functional categories. Proteins associated with highly specialized functions of the RPE, which are required for interaction with photoreceptor cells, including RPE65, cellular retinaldehyde-binding protein (CRALBP), and cellular retinol-binding protein (CRBP), were absent in dedifferentiated cultured RPE cells, whereas proteins involved in phagocytosis and exocytosis, including cathepsin D and clathrin were still present. Dedifferentiated RPE cells displayed a strong shift toward increased expression of proteins associated with cell shape, cell adhesion, and stress fiber formation, including cytokeratin 19, gelsolin, and tropomyosins, and also acquired increased expression of factors involved in translation and tumorigenic signal transduction such as annexin I and translation initiation factor (eIF)-5A. CONCLUSIONS: Dedifferentiation of human RPE cells in vitro results in downregulation of proteins associated with highly specialized functions of the RPE and induces the differential expression of proteins related to cytoskeleton organization, cell shape, cell migration, and mediation of proliferative signal transduction. These in vitro data suggest that the dedifferentiated status of RPE cells per se may initiate PVR. Further investigation of candidate proteins may identify additional targets for treatment or prevention of diseases associated with RPE dedifferentiation.

Cell Differentiation↗
PubMed2003

Light-absorbing properties and osmolarity of indocyanine-green depending on concentration and solvent medium.

PURPOSE: To evaluate the absorption spectrum and osmolarity of three currently used indocyanine green (ICG) products at different concentrations and with different solvent media. METHODS: The absorption spectrum and osmolarity of three different ICG products (Pulsion, Munich, Germany; Akorn, Buffalo Grove, IL; and Laboratoires SERB, Paris, France) were analyzed. Each ICG was further diluted with balanced salt solution or glucose 5%. Four different concentrations were evaluated: 0.005%, 0.0025%, 0.001%, and 0.00025%. ICG (Pulsion) diluted in viscoelastic material (Healon; Pharmacia, Stockholm, Sweden) was analyzed at a concentration of 0.0025%. The following parameters were measured: absorption spectrum between 400 and 1000 nm, osmolarity, and the emission spectrum of the light source of a commonly used vitrectomy machine (Megatron; Geuder, Heidelberg, Germany). RESULTS: Independent from the manufacturer, concentrations of 0.005%, 0.0025%, and 0.001% ICG diluted in balanced salt solutions (BSS and BSS Plus; Alcon Pharmaceuticals, Fort Worth, TX) and glucose 5% showed two maxima, one at approximately 700 nm and a second one at 780 nm. There was an increase from zero to maximum absorption between 600 and 700 nm and a return to zero between 800 and 900 nm. The absorption band of ICG diluted in the viscoelastic material was similar to the saline solution (BSS or BSS Plus)-diluted ICG. At lower concentrations of 0.001% or 0.00025%, the peak at 700 nm decreased, forming a shoulder in the curve, whereas the peak at 780 nm remained stable. Osmolarity was in the range of 302 to 313 mOsM for BSS Plus-diluted ICG. When glucose 5% was used for ICG dilution, absorption between 600 and 700 nm decreased, and osmolarity was lower (between 292 and 298 mOsM). The light source emission was between 380 and 760 nm. CONCLUSIONS: Dilution of ICG using the balanced salt solutions BSS or BSS Plus resulted in a steep increase of absorption starting at 600 nm. In clinical practice, there is an overlap between the absorption band of ICG and the emission curve of the light source, resulting in a possible photosensitizing effect, especially at higher ICG concentrations. This effect becomes less likely with decreasing ICG concentrations or when glucose 5% is used as a solvent medium.

Absorption↗