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Biomedical subjects

Anselm Kampik

Publications and source records attributed to Anselm Kampik.

At least 19 recordsLinked to original sources

Pulsed electron avalanche knife: new technology for cataract surgery.

BACKGROUND: The pulsed electron avalanche knife (PEAK-fc) is a new pulsed electrosurgical device that allows for precise, "cold" and traction-free tissue dissection. AIM: To evaluate the surgical applicability, safety and potential complications of PEAK-fc in complicated cataract surgery. METHODS: The study included five children with congenital cataracts, two patients with advanced senile cataracts, six adults with mature cataracts, three of them with posterior iris synechia, three patients with post-traumatic cataracts with zonulolysis, one patient with intumescent traumatic cataract and three patients with massive anterior capsule opacification. Anterior and posterior capsulotomies, iris synechiolysis, dissection of anterior capsule opacification and fibrotic scar tissue were performed. PEAK-fc was set at voltages of 500-700 V, pulse duration of 0.1 m and repetition rate of 40-100 Hz. RESULTS: Anterior and posterior capsulotomies were successfully and safely performed in all eyes. The edges of capsulotomies appeared sharp, showing only limited collateral damage. PEAK-fc worked best by just gently touching the capsule, thereby avoiding tractional forces or pressure on the lens capsule. Posterior iris synechiae could be released and anterior capsule opacification was dissected without complications. CONCLUSIONS: PEAK-fc is a very helpful cutting device for complicated cases of cataract surgery, especially for mature and congenital cataracts, traumatic zonulolysis or anterior segment complications after intraocular inflammation.

Adolescent↗

Endothelial cell density in donor corneas: a comparison of automatic software programs with manual counting.

PURPOSE: Several automated systems have become available to determine endothelial cell density (ECD) of donor corneas. The purpose of this study was the comparison of 2 systems, the Endothelial Analysis System EAT V1.4 (Rhinetec, Duesseldorf, Germany) and the NAVIS Cell Count Version 3.4.1 (Nidek Technologies, Erlangen, Germany), against manual ECD counts. METHODS: During organ culture, the endothelium of 50 human corneas was photographed on both conventional film and digitally. Manual fixed-frame counting was performed on 2 photographs by 3 experienced ophthalmologists. Three digital pictures of each cornea were analyzed semiautomatically on the Rhinetec EAT system V1.4. Images were imported and analyzed by the fully automatic mode of the NAVIS system V3.4.1 (which also offers a semiautomatic counting mode). In an additional experiment on 11 corneas, the NAVIS counts on the microscopy system previously used only for manual cell counts were directly compared with manual counts. RESULTS: Mean endothelial cell density obtained by manual counting of all observers was 2679 +/- 313 (SD) cells/mm. Values obtained by digital analysis with EAT were a mean of 1.3% higher (2713 +/- 286 cells/mm), which is not a significant difference. In contrast, analysis of the digital pictures with the fully automated NAVIS software mode showed a mean of 7.0% higher measurements (2867 +/- 111 cells/ mm), a significant difference (P = 0.0001). Altman-Bland analysis revealed that the fully automated NAVIS counts gave too low results for high ECDs and too high results for low ECDs. This result was confirmed by the direct comparison with manual counting. CONCLUSIONS: Fully automated analysis of ECD remains problematic. Validation of any computer-assisted system against manual counting is of importance.

Adolescent↗

Visual quality of life after macular hole surgery: outcome and predictive factors.

BACKGROUND: In the present study we evaluated the functional success after macular hole surgery in correlation to visual quality of life and looked for predictive factors determining surgical success. METHODS: Fifty-nine patients that underwent pars plana vitrectomy for idiopathic macular hole were included. Follow-up visits were performed in regular intervals after surgery and included a clinical examination, optical coherence tomography (OCT) and measurement of visual acuity. To assess the visual quality of life patients filled out the National Eye Institute 25-item Visual Function Questionnaire (VFQ-25) before and three months and one year after surgery. RESULTS: Macular hole closure was achieved in 57 of 59 patients (97%). Mean visual acuity increased from 20/100 preoperatively to 20/34 one year after surgery (p = 0.02). Despite good visual acuity (20/27) in the fellow eye, visual quality of life (VFQ composite score) rose from 75.9 +/- 14.4 (SD) to 81.5 +/- 14.2 one year after surgery (p<0.001). Although there was no correlation between the increase in visual quality of life and visual acuity, the increase in VFQ-25 could be well predicted: low visual acuity and significant impairment on VFQ-25 testing preoperatively made patients most likely to benefit from macular hole surgery. A relatively high retinal thickness measurement at the hole border measured on OCT further increases the predictive value. CONCLUSION: Macular hole surgery is associated with an increase in visual quality of life despite good visual acuity of the fellow eye. Preoperative visual acuity, VFQ-25 value and partly OCT may help to predict the increase in patients' vision related quality of life after surgery.

Aged↗

In vivo confocal microscopy of pigmented conjunctival tumors.

PURPOSE: To analyze the appearance of conjunctival pigmented tumors as seen by in vivo confocal microscopy. METHODS: Twenty-eight pigmented conjunctival tumors including 6 nevi, 13 acquired melanoses, 7 conjunctival melanomas, and 2 extrascleral growths of uveal melanomas were examined by in vivo confocal microscopy using the Heidelberg Retina Tomograph (HRTII)/Rostock Cornea Modul (RCM). Confocal images were analyzed using predefined criteria by an observer masked to final histological diagnosis and a preliminary diagnosis was established. After excision, histology and immunohistochemistry using antibodies against S-100, Melan-A, HMB-45, Ki-67, CD3, and CD68 were performed in all specimens and compared with in vivo confocal images of the same lesions. RESULTS: Confocal microscopy images confirmed typical histopathological features of conjunctival pigmented tumors. Nest or diffuse collections of medium-sized uniform hyper- or hyperreflective cells in the stroma and stromal cysts lined with a multilayered epithelium were visible in 100% of conjunctival nevi. Small dendritic cells were typically observed in 100% of primary acquired melanoses (PAM) without atypia and in 2 out of 6 nevi. Large networks of hyperreflective dendritic cells were present in 100% of PAM with atypia. Whereas images of PAM without atypia and secondary complexion-associated melanosis showed hyperreflective granules confined to the basal epithelium in 67% of lesions, PAM with atypia presented with hyperreflective granules and patches throughout the epithelium in all cases. Malignant melanomas of the conjunctiva and extrascleral growths of uveal melanomas demonstrated large hyperreflective cells with prominent nuclei and nucleoli. In vivo confocal microscopy showed a sensitivity of 89% and a specificity of 100% to establish the correct diagnosis of conjunctival melanoma compared with histology. CONCLUSIONS: High correlations were found between in vivo confocal microscopy using near-infrared laser light and histology in the diagnosis of pigmented conjunctival lesions. In vivo confocal microscopy seems to be a valuable new tool in the differential diagnosis and follow-up of pigmented conjunctival tumors. It does not replace histology, but may assist in performing guided biopsy in tumors suspected clinically and/or with in vivo microscopy. In addition, in vivo confocal microscopy may support the clinical diagnosis of extrascleral involvement in uveal melanoma.

Adolescent↗

Light absorbing properties of indocyanine green (ICG) in solution and after adsorption to the retinal surface: an ex-vivo approach.

BACKGROUND: To evaluate potential differences in light absorbing properties and stability of indocyanine green (ICG) adsorbed to the retinal surface and of ICG dissolved in water and balanced salt solution. METHODS: The retina of four human donor eyes was prepared by removing the vitreous from the retinal surface. The inner surface of the specimen was covered with two to three drops of a 0.05% or 0.15% ICG solution respectively. After 1 min, the dye was removed by careful irrigation using BSS plus. The retinal specimens were then investigated by diffuse reflection spectroscopy (UV/VIS/NIR Spectrometer Lambda 900/Perkin Elmer equipped with a PELA-1020 integrating sphere accessory) and their absorption evaluated by the Kubelka-Munk function. To control the sensitivity of the setting, diffuse reflectance spectra of ICG adsorbed to a cellulose membrane and Al(2)O(3) were measured. For comparison, absorption spectra of ICG dissolved in water and BSS plus solution were measured in relation to ICG concentration and time using an UV/VIS/NIR Spectrometer Lambda 900/Perkin Elmer. RESULTS: On the retinal surface, absorption spectra exhibited a steep increase of absorption beginning at 620 nm, with a maximum at 736 nm (0.05%) and a shoulder at 745 (0.15%) and a second maximum at approximately 800 nm for both concentrations. Repeated measurement of the retinal surface 13 days after the ICG exposure revealed no changes in the position of the maxima as compared to the initial measurements. Light absorbing properties of ICG on cellulose or Al(2)O(3) are similar to those seen on the retinal surface with respect to the pattern and location of absorption maxima. In contrast, ICG dissolved in water or BSS plus disclosed variations in absorption characteristics depending on dye concentration, solute and time of measurement. CONCLUSIONS: Absorption characteristics and stability of ICG bound to the retinal surface could be of relevance when investigating potential pathomechanisms of ICG related toxicity, which might be related not only to intraoperative but also to postoperative light exposure of patients after intravitreal use of ICG.

Acetates↗

In vivo confocal microscopy of filtering blebs after trabeculectomy.

OBJECTIVES: To analyze filtering blebs after trabeculectomy by means of in vivo confocal microscopy and to correlate the images with clinical bleb appearance and function. METHOD: In vivo confocal microscopy using the Heidelberg Retina Tomograph/Rostock Cornea Module (Heidelberg Engineering, Heidelberg, Germany) was performed in 53 filtering blebs in 45 patients 6 days to 30 years postoperatively. RESULTS: In vivo confocal microscopic findings significantly correlated with good bleb function included the number of epithelial microcysts (P = .03), a large total stromal cyst area (P = .009), the absence of encapsulated stromal cysts (P = .002), minimal vascularization (P = .05), and the absence of tortuous conjunctival vessels (P = .01). In contrast, a hyperreflective condensed bleb stroma was significantly associated with bleb failure (P<.001). Bleb stroma mainly consisting of a rarified collagenlike network was significantly linked to trabeculectomy performed with mitomycin C (P = .001). Epithelial and stromal inflammation were observed at a median of 1 and 4 months after surgery, respectively. CONCLUSIONS: In vivo confocal microscopy using the Heidelberg Retina Tomograph/Rostock Cornea Module permits diagnostic imaging of filtering blebs and differentiation between good and insufficient bleb function. Moreover, the postoperative inflammatory reaction can be monitored directly for adapted postoperative anti-inflammatory treatment.

Adult↗

Ultrastructure of the vitreomacular interface in full-thickness idiopathic macular holes: a consecutive analysis of 100 cases.

PURPOSE: To evaluate the ultrastructure of the vitreoretinal interface in stage III and stage IV idiopathic macular holes. DESIGN: A consecutive observational case series, laboratory investigation. METHODS: Pars plana vitrectomy with en-bloc removal of the internal limiting membrane (ILM) and epimacular tissue was performed by one surgeon in 80 eyes with stage III macular holes and in 20 eyes with stage IV macular holes. In total, 218 specimens were processed for light and transmission electron microscopy. RESULTS: Fibrocellular proliferation at the vitreal side of the ILM was found in 57 cases. Native vitreous collagen (NVC) was attached to the ILM in 36 eyes. The presence of NVC was considerably more frequent in eyes with stage IV (70%) than in eyes with stage III macular holes (26%). Mono- and multilayered cellular membranes were seen more frequently in stage IV macular holes. NVC, if present, was always associated with fibrocellular proliferation. In 39 eyes with stage III and in four eyes with stage IV macular holes, the ILM was devoid of any cells and collagen. CONCLUSIONS: Fibrocellular proliferation appears to be a secondary event instead of a primary feature in macular hole development. The severity of fibrocellular proliferation is associated with the presence of NVC. Incomplete vitreoretinal separation may contribute to the development of epimacular membranes in eyes with idiopathic macular holes. Remnants of the vitreous cortex remain more often attached to the ILM in eyes with spontaneous posterior vitreous detachment (PVD) than in eyes with surgical PVD induction.

Aged↗

Pulsed electron avalanche knife for capsulotomy in congenital and mature cataract.

The pulsed electron avalanche knife (PEAK-fc, Carl Zeiss Meditec) is an electrosurgical cutting device that allows precise "cold" and traction-free tissue dissection. We describe its applicability and safety for anterior capsulotomy in a child with congenital cataract and an adult patient with mature cataract. The PEAK-fc was set at a voltage of 600 V and a pulse repetition rate of 80 Hz. Anterior capsulotomies were successfully and safely performed in both cases, with the edges of capsulotomies appearing sharp and showing only limited collateral damage. The PEAK-fc appears to be a helpful cutting device for complicated cases of cataract surgery, especially for mature and congenital cataracts.

Cataract↗

Differential protein profiling of primary versus immortalized human RPE cells identifies expression patterns associated with cytoskeletal remodeling and cell survival.

Functional research of retinal pigment epithelium (RPE) most often relies on utilization of RPE-derived cell lines in vitro. However, no studies about similarities and differences of the respective cell lines exist so far. Thus, we here analyze the proteome of the most popular RPE cell lines: ARPE-19 and hTERT and compare their constitutive and de novo synthesized protein expression profiles to human early passage retinal pigment epithelial cells (epRPE) by 2-D electrophoresis and MALDI-TOF peptide mass fingerprinting. In all three cell lines the baseline protein expression pattern corresponded well to the de novo synthesized cellular proteome. However, comparison of the protein profile of epRPE cells with that of hTERT-RPE cells revealed a higher abundance of proteins related to cell migration, adhesion, and extracellular matrix formation, paralleled by a down-regulation of proteins attributed to cell polarization, and showed an altered expression of detoxification enzymes in hTERT-RPE. ARPE-19 cells, however, exhibited a higher abundance of components of the microtubule cytoskeleton and differences in expression of proteins related to proliferation and cell death. epRPE cells, hTERT-RPE, and ARPE-19 therefore may respond differently with respect to certain functional properties, a finding that should prove valuable for future in vitro studies.

Cell Culture Techniques↗

Evaluation of the internal limiting membrane after conventional peeling during macular hole surgery.

We evaluated the histologic features of the internal limiting membrane (ILM) of the retina removed during macular hole surgery without indocyanine green staining. Our investigation focused on the presence or absence of retinal structures adherent to the retinal surface of the ILM. Because only tiny retinal cellular fragments were observed especially in ILM folds, we conclude that conventional ILM peeling can be performed safely with a cleavage plane between the retinal surface of the ILM and Müller cell endfeet.

Aged↗

Immunohistochemical findings after LASIK confirm in vitro LASIK model.

PURPOSE: To compare immunohistochemical findings in human donor corneas after successful laser in situ keratomileusis (LASIK) without clinical complications with a recently established human LASIK in vitro model. METHODS: Donor corneas with prior LASIK treatment were investigated. Cryostat sections were stained immunohistochemically for collagen types I, III, and VI and laminin and fibronectin. RESULTS: With light microscopy, the interface of the LASIK flap could hardly be detected. In all samples, fibronectin was consistently detected along the entire extent of the surgical wound. In contrast, collagen type III and laminin only stained the superficial portion of the LASIK incision site. Staining for collagen types I and VI showed no changes after LASIK. CONCLUSION: Histologic findings in donor corneas with prior LASIK treatment confirm histologic observations in a recently introduced human organ culture LASIK model. This strengthens the reliability of the latter LASIK model for further studies concerning wound healing after LASIK surgery.

Adult↗

In vivo confocal microscopy of normal conjunctiva and conjunctivitis.

PURPOSE: To analyze the appearance of normal conjunctiva and conjunctival inflammation by in vivo confocal microscopy. METHODS: Conjunctiva of 15 normal patients and 21 patients with conjunctivitis including bacterial, papillary, follicular, granulomatous, and cicatrizing disease were analyzed by the Heidelberg retina tomograph (HRTII)/Rostock cornea modul (RCM). RESULTS: Scans of normal bulbar and tarsal conjunctiva corresponded well to the established anatomy except for a prominent, thickened epithelial basement membrane observed by in vivo microscopy. Presumed goblet cells were visible throughout the conjunctival epithelium. Adenoid structures and hair follicles were discernible in the tarsal conjunctiva in vivo. Conjunctival perfusion could be observed directly. Acute and chronic inflammatory cells, conjunctival papillary, and follicular reactions, as well as conjunctival cicatrization, could be discriminated. In a patient with conjunctival granuloma, in vivo confocal microscopy disclosed suture material inside the lesion. CONCLUSION: Confocal microscopy using near-infrared laser light is a useful new tool in the analysis of conjunctival tissue in vivo. It is a valuable aid in the differential diagnosis of conjunctival inflammation and thus may guide therapeutical decisions.

Adult↗