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Biomedical subjects

A Kampik

Publications and source records attributed to A Kampik.

At least 109 records · Page 6Linked to original sources
PubMed1999

[Preoperative infection prophylaxis with 1% polyvidon-iodine solution based on the example of conjunctival staphylococci].

BACKGROUND: Most germs causing postoperative endophthalmitis derive from the conjunctival bacterial normal flora. Postoperative endophthalmitis is often induced by staphylococcal germs. The application of polyvidone-iodine solution to the conjunctiva is one possibility to reduce potential endophthalmitis-causing bacteria. The aim of this study was to evaluate the effectiveness of 1% polyvidone-iodine solution concerning the reduction of colonization with staphylococci in the course of intraocular surgery. This is to evaluate the effectiveness of 1% polyvidone-iodine solution concerning coagulase-negative and positive staphylococci. PATIENTS AND METHODS: Patients with intrabulbar surgery (300) had three conjunctival swabs taken: the first immediately prior to preoperative preparation in the operating theatre, following in-patient application of antibiotic eye drops (Polymyxin-B-sulfat, Neomycinsulfat and Gramicidin in combination); the second swab was taken after antisepsis with polyvidone-iodine before opening the conjunctiva. At the end of surgery the third smear was taken. RESULTS: In 30.3% staphylococci were isolated from eyes before disinfection. Some patients (7.7%) were staphylococci-positive after disinfection; 5.3% of the patients showed staphylococcal growth at the end of surgery. To evaluate the effectiveness of polyvidone-iodine 1% solution we compared the first and the second smear (Mc Nemar). We found a statistically significant reduction (P < 0.001). At the end of surgery the conjunctival colonization with staphylococcal germs remained statistically significant reduced (P < 0.001). The mean operation time was 37 +/- 24 min. CONCLUSIONS: We concluded that a significant reduction of a staphylococcal colonization can be achieved by preoperative application of polyvidone-iodine (1%) (P < 0.001). Even at the end of surgery the effect of 1% polyvidone-iodine solution held.

Anti-Bacterial Agents↗
PubMed1999

[Intra-vitreal rt-PA and gas introduction in submacular hemorrhage].

UNLABELLED: Efficacy and complications of intravitreally injected tissue plasminogen activator (rt-PA) and sulfahexafluoride gas (SF6) in submacular hemorrhage are demonstrated. PATIENTS AND METHODS: Fifty-three patients with submacular hemorrhage were treated (27 women, 26 men, mean age 79 +/- 1 years). Causes of hemorrhage were a choroidal neovascularization in 47 patients and macroaneurysm in 6 patients. After i.v. administration of 500 mg acetazolamide and disinfection of the conjunctiva, 50 micrograms rt-PA in 0.1 ml (BSS) and 0.5 ml SF6 were injected intravitreally. The patient was positioned prone for 24 h. RESULTS: In 23 patients with choroidal neovascularization visual acuity improved by 2 lines and more; in 12 patients vision remained unchanged. In 12 patients visual acuity deteriorated. In 5 of 6 patients with a macroaneurysm vision improved from less than 0.1 to 0.1-0.5. Postoperative complications were four cases of vitreous hemorrhage and one case of endophthalmitis. CONCLUSION: The intravitreal injection of rt-PA and SF6 is an alternative method for treatment of submacular hemorrhage.

Aged↗
PubMed1999

Surgical extraction of subfoveal choroidal new vessels and submacular haemorrhage in age-related macular degeneration: results of a prospective study.

BACKGROUND: The surgical extraction of subfoveal choroidal new vessels (CNV) is one of several possibilities to treat subfoveal CNV or haemorrhages in age-related macular degeneration (ARMD). METHODS: Prospective study, follow-up 3-6 months. Clinical and angiographic differentiation of three subgroups: (1) subfoveal well-defined CNV (24 eyes); (2) subfoveal ill-defined CNV with or without well-defined components (10 eyes); (3) submacular haemorrhages (20 eyes). RESULTS: The mean and median visual acuity and the proportion of eyes with > or = 20/200 vision increased slightly in group 1 and decreased slightly in group 2; the differences were not significant. Group 3 demonstrated mean improvement but was heterogeneous, depending on the site and type of underlying CNV. The proportion of eyes with 3 or more lines of improvement after 3 months was 35.3% (7/17), 10% (1/10) and 38.9% (7/18) respectively. The proportion of eyes with a loss of 3 or more lines after 3 months was 5.9% (1/17), 20% (2/10) and 5.6% (1/18) respectively. The recurrence rate was 29.2% (7/24), 8.3% (1/11) and 25% (5/20). Intraoperative complications were iatrogenic central tears in 7.3% (4/55), peripheral tears in 14.5% (8/55) and peripheral retinal detachment in 3.6% (2/55). A postoperative retinal detachment was observed in 2 of 55 eyes (3.6%). All these complications could be managed without ill effect. CONCLUSION: Subfoveal surgery might preserve remaining retinal function in eyes with well-defined CNV. However, subgroups of the MPS subfoveal laser trials with comparable initial visual acuity demonstrated postoperative functional stabilisation and similar recurrence rates in well-defined CNV. Though selected cases of submacular haemorrhage did profit from surgery, TPA-assisted gas injection will probably be a better alternative. Unfortunately, surgery for ill-defined CNV, found in the vast majority of eyes with exudative ARMD, seems to worsen the natural course. Surgery has to be combined with restoration of Bruch's membrane before it can become a possible therapeutic option in ARMD.

Aged↗
PubMed1999

CuZn superoxide dismutase transgenic retinal transplants.

BACKGROUND: The morphology of retinal transplants is believed to depend on the extent of mechanical disruption of the donor tissue during the surgical procedure and on local factors of the host environment. We hypothesized that oxidative stress during donor tissue preparation and implantation further affects transplant development and investigated the effects of CuZn superoxide dismutase (SOD) overexpression on the survival and morphological development of mouse embryonic retinal transplants. METHODS: Retinae and livers from embryonic day 14-15 SOD overexpressing transgenic mice and CBA control mice were harvested under sterile conditions. In order to identify transgenic mouse embryos, the embryonic livers were analyzed via nondenaturing gel-electrophoresis for the presence of the human SOD protein. Neural retinae were transplanted as fragmented tissue into the subretinal space of albino BALB/c mice. At 4-8 weeks following transplantation, the grafted eyes were fixed in Bouin's solution and processed for histological analysis. RESULTS: Both SOD transgenic and control retinal transplants had developed all retinal layers except for a ganglion cell layer and exhibited a similar extent of rosette formation. Computer-assisted, quantitative assessment of retinal graft volumes revealed a significant, around 58% increase in size of SOD transgenic transplants compared with controls. CONCLUSIONS: Enhanced intracellular SOD levels do not seem to influence retinal transplant morphology as detected by light microscopy. However, volumes of the SOD transgenic transplants were found to be increased compared to control grafts.

Animals↗
PubMed1999

In vivo imaging of the human zonular apparatus with high-resolution ultrasound biomicroscopy.

BACKGROUND: To investigate the potential of high-resolution ultrasound biomicroscopy (UBM) for studying the zonular apparatus of human beings in vivo. METHODS: Using transducer frequencies of 34 MHz and 50 MHz, criteria were developed to identify transcorneal and transscleral sections that allowed reproducible identification of the different fiber groups of the zonular architecture. For that purpose, 10 volunteers between the ages of 14 and 41 years underwent high-resolution ultrasound biomicroscopy under conditions of consensual far- and near-accommodation. The online video recordings of the respective UBM investigations were afterwards analyzed image by image. Good visibility of zonular fibers was obtained when the ultrasound wave propagation comprised an angle close to 90 degrees with the fiber orientation and when the oscillations of the UBM scan had a strict radial orientation towards the limbus and avoided, simultaneously, the ciliary processes. RESULTS: In all the volunteers, high-resolution ultrasound biomicroscopy imaged the zonular fiber groups known from histology. In addition, it detected fibers that do not follow the course of the inner ciliary body surface but take a direct route from the ora serrata to the lens. It also demonstrated that fibers that seem to change direction at crossings with other fibers. Under conditions of near-accommodation, the zonular fibers showed signs of relaxation. CONCLUSIONS: High-resolution ultrasound biomicroscopy seems well suited for in vivo investigations of the zonular apparatus and of accommodation in man. The results support the fundamental features of the Helmholtz theory on accommodation.

Accommodation, Ocular↗
PubMed1999

Evaluation of microvascularization pattern visibility in human choroidal melanomas: comparison of confocal fluorescein with indocyanine green angiography.

BACKGROUND: The presence of specific microvascularization patterns (networks, parallel with and without crosslinking, silent) in histological sections of human choroidal melanomas has prognostic significance for survival. We showed previously in selected patients that the identification of these microvascularization patterns is possible in vivo by using confocal scanning laser indocyanine green angiography and that this technique is superior to fluorescein angiography using a conventional acquisition technique with a fundus camera. We now routinely use simultaneous confocal fluorescein/indocyanine green angiography to study microvascularization patterns in choroidal melanomas. The purpose of this study was to compare the visibility of tumor vessels and microvascularization patterns in fluorescein and indocyanine green angiography in simultaneous confocal series taken with the same instrument in a large prospective series of patients. PATIENTS AND METHODS: The simultaneously procured confocal fluorescein and indocyanine green angiograms of 50 patients with untreated choroidal melanomas (maximal apical height according to standardized A-scan between 2 and 8 mm) were studied for the visibility of tumor vessels and microvascularization patterns. At least one simultaneous confocal optical series (32 images in sequential depth order) during the early arterial venous phase was obtained per patient. RESULTS: Confocal forescein angiography disclosed signs of tumor vascularization in 12 (24%) of the 50 patients examined. However, in only 3 patients (6%) could microvascularization patterns be identified using confocal fluorescein angiography, and only in the very early arterial phase, which is often difficult to capture. In contrast, simultaneously obtained confocal indocyanine green angiograms disclosed tumor vessels in 47 (94%) of the examined 50 patients and microvascularization patterns could be identified in all of these cases. In 3 patients (6%) no tumor vessels could be detected within the tumor borders. CONCLUSION: This study demonstrates that confocal indocyanine green angiography images microvascularization patterns in choroidal melanomas better than fluorescein angiography, even when the images are acquired with the same technique. This can be explained with the different absorption, fluorescence and exudation characteristics of these dyes. In vivo imaging of these microvascularization patterns using confocal indocyanine green angiography offers the possibility of assessing the prognosis of choroidal melanomas without the removal of tissue.

Adult↗
PubMed1999

[Color vision in relation to age: a study of normal values].

BACKGROUND: It is difficult to quantify thresholds in most colour vision tests, and this is especially the case for tritan hues, where a strong age-related increase of threshold has been reported. With the development of computer-graphic methods it is possible to remove brightness clues caused by lens absorption. This study attempts to give normative values for colour contrast thresholds and assess the age related changes therein. PATIENTS AND METHODS: 115 patients aged between 6 & 71 years were tested for central and peripheral colour contrast sensitivity. No patient had any systemic or eye disease. As a preliminary, heterochromatic flicker balance between the luminosities of the R and G and B and G phosphors was established, so that all colours subsequently generated were isoluminant for the person tested. Then, using a modified binary search technique, colour contrast thresholds were established using both 2 degree optotypes, for central vision, and a ring, 12.5 degrees in radius for peripheral vision. In the latter case, the observer had to name the position of the missing quadrant in the ring. Stimuli were presented for 200 msec at 1 Hz. Colours were modulated on protan, deutan or tritan colour axis. RESULTS: No correlation between age and central colour vision thresholds was observed. By contrast a significant but only minor increase of peripheral colour vision threshold was observed for the peripheral protan and tritan axis. DISCUSSION: The present system removes luminance clues from colour vision tests and permits both central and peripheral retina to be tested. The results are simple in that the influence of age can be neglected. The variability of threshold results is small, and it is easy to detect the relatively large changes associated with disease. Since high-quality monitors are standardised and calibrated, providing the stimulus parameters described are adhered to, the results given here for upper limits of normal may be used for other similar systems.

Adolescent↗
PubMed1999

[What is the value of transpupillary thermotherapy in treatment of flat posterior choroid melanomas? A systematic review of the literature?].

BACKGROUND: Transpupillary thermotherapy is a relatively new method for the treatment of choroidal melanomas. We present a systematic survey of the current literature. METHOD: A temperature rise in the tumor ranging from 45-60 degrees C is achieved by an infrared laser beam delivered through the dilated pupil. With a modified delivery system beam widths between 1 and 3 mm and exposure times of one minute are generated. Thus, tumors of up to 4 mm thickness are treatable. TTT can be used as a single treatment procedure or in combination with brachytherapy. RESULTS: Several studies presented in the literature show a satisfactory local tumor control. However, there is a significant risk of vision threatening side effects like retinal vascular occlusion or retinal traction in selected cases. CONCLUSION: The TTT is a minimal invasive procedure for the treatment of flat choroidal melanomas of the posterior pole which is capable of achieving a good local tumor control. Studies with more patients and longer follow-up will demonstrate if TTT is also beneficial in the longterm management of choroidal melanomas.

Choroid↗
PubMed1999

[Bacterial keratitis in patients with and without contact lens anamnesis].

BACKGROUND: The study shows differences between contact lens wearers and patients without history of contact lenses regarding the spectrum of etiological agents in bacterial keratitis. Based on microbiological analysis, there are given recommendations for an optimal initial antibiotic treatment in both groups. MATERIAL AND METHODS: From 1989 to 1997 smears, scrapings and corneal biopsies were taken from 218 patients with bacterial keratitis. The causing pathogens were isolated on directly inoculated culture media and identified by staining and microscopy. The resistance pattern of a total of 275 germs was analysed for different antibiotics. RESULTS: The most frequently isolated germs were Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus spp., Propionibacterium acnes and Pseudomonas aeruginosa. Whereas sensitive gram-positive germs were predominating in contact lens wearers as well as in non-contact lens wearers, multiresistant gram-negative germs could nearly exclusively be isolated from contact lens wearers. Frequently administered antibiotics like aminoglycosides and quinolones are effective in infections caused by Staphylococcus spp., but increasing resistance could be seen to Streptococcus spp. In this case, erythromycin is very sensitive. Gram-negative germs like Pseudomonas aeruginosa are sensitive to quinolones and some aminoglycosides (e.g. tobramycin). CONCLUSION: In contact lens wearers, more aggressive germs have to be considered than in non-contact lens wearers. In such cases, frequently administered antibiotics like amino-glycosides are not effective. To cover problematic gram-negative germs we recommend the application of quinolones alternating with erythromycin. The latter one is more effective than quinolones and aminoglycosides in case of Streptococcus spp. co-involvement.

Adult↗
PubMed1999

Removal of silicone oil with vision improvement after rhegmatogenous retinal detachment following CMV retinitis in patients with AIDS.

PURPOSE: To report that silicone oil may be safely removed from immuno-recovered patients with acquired immunodeficiency syndrome (AIDS) after instillation for cytomegalovirus (CMV)-related rhegmatogenous retinal detachment. METHOD: We report two patients with CMV-related retinal detachment who had previously been treated with vitrectomy and silicone oil. RESULTS: Six months after removal of silicone oil, the retina remained attached in both patients. Without specific anti-CMV therapy, there was no relapse of CMV retinitis while patients were undergoing highly active antiretroviral therapy. Best-corrected visual acuity improved in both patients. CONCLUSION: It appears to be possible to remove silicone oil safely from patients with AIDS who show immune recovery, thus avoiding side effects of long-standing silicone oil and increasing quality of life. After silicone oil removal, visual acuity was improved.

AIDS-Related Opportunistic Infections↗
PubMed1998

[Post-traumatic endophthalmitis after penetrating eye injuries. Risk factors, microbiological diagnosis and functional outcome].

BACKGROUND: Endophthalmitis associated with penetrating injury represents a distinct kind of intraocular infection. The preceding trauma, infective agents and inflammatory changes determine the functional outcome. MATERIALS AND METHODS: In a retrospective study, 18 patients with endophthalmitis were investigated and compared to a control group of 54 patients with penetrating ocular trauma. A number of clinical variables were evaluated for association with an increased risk of endophthalmitis. RESULTS: Risk factors found to be significant were: (1) a purely corneal wound, (2) surgical primary repair more than 24 h after injury and (3) initiation of intravenous antibiotic therapy later than 24 h after trauma. A two-fold increased relative risk was related to the presence of an intraocular foreign body, lens injury and a wound length less than 5 mm. Direct inoculation of surgical specimens and immediate microbiological processing succeeded in the presumptive identification of infective agents with preliminary therapeutic recommendations in 72% of the patients. CONCLUSIONS: In "risk eyes" particular attention should be paid to prophylaxis and signs of infection.

Bacteria↗
PubMed1998

[Choroid neovascularization in age-related macular degeneration. Correlation of histological and fluorescence angiography findings].

BACKGROUND: Recent studies have raised confusion about the fluorescein angiographical and histopathological correlation of CNV. MATERIAL AND METHODS: The preoperative fluorescein angiograms of four patients with subfoveal CNV due to ARMD extracted by pars plana vitrectomy were classified as wellor ill-defined CNV and were correlated to the histopathologically (in serial sections) verrified CNV-location (subneuroretinal (= type II according to Gass) versus sub-RPE (type I according to Gass)). RESULTS: The locations of all four CNV could be classified by histopathological landmarks as there were RPE, BLD/drusen, and inner Bruchs membrane. Angiographically welldefined membranes were type II membranes according to Gass, whereas the ill-defined membrane represented type I. The CNV with well- and ill-defined borders consisted of type II and type I parts according to Gass. CONCLUSION: We find subneuroretinal locations of the well-defined CNV examined (type II membranes according to Gass). Correspondingly, ill-defined CNV or ill-defined parts of a CNV seem to be beneath the RPE (type I). The correlation of fluorescein angiography and histopathology should be studied in greater numbers of well- and ill-defined CNV.

Bruch Membrane↗
PubMed1998

[Recurrent choroid neovascularization in age-related macular degeneration. Fluorescein angiographic morphology after surgical membranectomy].

UNLABELLED: The surgical removal of choroidal neovascularization (CNV) in age-related macular degeneration (AMD) causes a retinal pigment epithelial defect (RPED) corresponding to the area of diffuse RPE damage. We describe angiographic features of recurrent CNV in AMD after surgical membranectomy in order to elucidate the nature of persistence and recurrence. METHODS: After digitalization of the pre- and postoperative fluorescein angiographic images of eight patients with recurrent CNV in AMD we determined the morphology (well or ill-defined) and the area of the CNV and of the subretinal hemorrhage preoperatively and of the recurrent CNV and of the RPE defect postoperatively. RESULTS: The nature of recurrences showed differences between preoperatively well- and ill-defined CNV. Four preoperatively well-defined CNV with surrounding subretinal hemorrhage showed recurrences in the entire area of the preoperative CNV excluding the retinotomy 8-9 weeks postoperatively. Four preoperatively ill-defined CNV with subretinal hemorrhage developed marginal recurrences at the rim of the RPED. There was no background fluorescence in the area of the RPED. CONCLUSION: The nature of recurrences extending over the entire area of the preoperatively well-defined CNV without loss of background fluorescence only a few weeks after surgical removal of well-defined CNV suggests partial persistence. The removal of the subretinal well-defined CNV could leave sub-RPE parts in locations that preoperatively cannot be visualized angiographically. The marginal recurrence of preoperatively ill-defined CNV weeks to months postoperatively shows angiographic similarities to recurrent CNV after laser coagulation.

Aged↗
PubMed1998

[Bacterial colonization of conjunctiva with Propionibacterium acnes before and after polyvidon iodine administration before intraocular interventions].

BACKGROUND: Propionibacterium acnes has been described as a causative agent of postoperative endophthalmitis. This gram-positive, immotile, non-spore-forming bacterium is highly pleomorphic and grows under conditions of low to no oxygen concentration. It is commonly found on the skin at the openings of sebaceous glands and on hairs. A near-symptomless postoperative endophthalmitis occurs particularly when Propionibacteria are enclosed in the capsular bag. We investigated to what extent the number of P. acnes in the conjunctival sac can be reduced by preoperative disinfection with polyvidone iodine (1%). PATIENTS AND METHODS: A total of 261 patients with intrabulbar surgery had two conjuctival swabs taken: the first immediately prior to preoperative preparation in the operating theatre, following in-patient application of antibiotic eye drops (Polymyxin-B-sulfat, Neomycinsulfat and Gramicidin in combination); the second swab was taken after disinfection with polyvidone iodine before opening the conjunctiva. RESULTS: Of the 261 swabs, 60 (23%) taken prior to polyvidone iodine application were positive for Propinibacterium acnes. Following polyvidone iodine treatment, a further 5 (1.9%) remained culture-positive. After disinfection, 55 (92%) of the 60 positive swabs for Propionibacterium acnes remained culture-negative. CONCLUSIONS: We concluded that a significant reduction of P. acnes can be achieved by preoperative application of polyvidone iodine (1%) (P < 0.001).

Anti-Infective Agents, Local↗
PubMed1998

Ultrastructure of epiretinal membranes associated with macular holes.

BACKGROUND: The role of tangential traction exerted by epiretinal membranes in the pathogenesis of macular holes is not fully understood. Furthermore, the role of glial cells in the formation and/or closure of macular holes remains to be elucidated. METHODS: To better understand the pathogenesis of macular hole formation and to compare the ultrastructural features of epiretinal membranes associated with macular holes of primary and secondary etiology, we harvested 23 translucent epiretinal membranes associated with macular holes stages III-IV at the time of pars plana vitrectomy and examined them electron microscopically. Eighteen membranes were obtained from patients with idiopathic macular holes. 3 membranes from patients with myopic macular holes and 2 epiretinal membranes were associated with macular holes which had developed after retinal detachment surgery. RESULTS: Eighteen membranes contained a continuous undulating piece of inner limiting lamina (ILL). Sixteen of 18 epiretinal membranes at the margins of idiopathic macular holes, 2 of 3 membranes in myopic macular holes and both membranes associated with a macular hole after retinal detachment surgery demonstrated mono- or multilayers of fibrous astrocytes with single macrophage- or fibrocyte-like cells. Vitreous and newly formed collagen occupied the space between the ILL and the glial cells. Three macular holes were surrounded by rather firmly attached acellular ILL. CONCLUSIONS: Glial cells and newly formed collagen may play an important role in macular hole formation by exerting tangential traction regardless of the underlying disease process. Glial cells, however, may also be involved in healing of the retinal defect and pars plana vitrectomy with peeling of an epiretinal membrane, and/or the ILL may induce directed glial cell proliferation and migration. The similar ultrastructure of epiretinal membranes associated with macular holes and "simple epiretinal membranes" as described by Foos [8] suggests a common pathogenesis for macular holes and macular pucker.

Adult↗