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W Förster

Publications and source records attributed to W Förster.

At least 19 recordsLinked to original sources
PubMed2002

[Necrosis of the semilunar bone--what is possible in ambulatory operations?].

The author has been operating on cases of lunatum necrose using all usual operating methods, excluding attached vessel pisiforme transfer, increasingly over the past 9 years without an overnight stay in hospital being necessary for patients. Depending on the quality of the structure, we have not experienced any disadvantages in comparison to hospitalised patients. Regarding funding: The costs of these operations are covered and are justifiable in combination with additional hand operations within the outpatients department.

Ambulatory Surgical Procedures↗
PubMed1998

Steep central islands after myopic photorefractive keratectomy.

PURPOSE: To investigate the formation of steep central islands and their reduction under modified experimental conditions. SETTING: University Eye Hospital Münster and Schwind Co., Kleinostheim, Germany. METHODS: Corneas of enucleated intact bovine eyes were treated with the Schwind Keratom. All experimental conditions were repeated six times in six different corneas. Eight experimental groups were looked at. Fluence was 180 to 200 mJ/cm2. Ablation mode (phototherapeutic keratectomy ([PTK] and standard myopic photorefractive keratectomy [PRK]), internal repetition rate (3 to 30 Hz), and ablation diameter (5 to 8 mm) and depth (4 to 15 diopters [D] in PRK) were varied. Modifications to reduce or avoid steep central islands included blowing nitrogen gas and aerosol over the cornea, cleaning the cornea of fluid, and using an anti-central-island software program. RESULTS: In PTK, an increase in the internal repetition rate resulted in a decrease in the height of the steep central island. In standard PRK, increasing refractive correction up to -8.0 D and increasing the ablation diameter resulted in an increase in steep central island power. The anti-central-island program, blowing aerosol, and cleaning the cornea reduced the formation of steep central islands and blowing nitrogen gas eliminated them. CONCLUSION: Steep central islands are created by a wide-field ablation process and are probably caused by many factors. Both software and hardware modifications can be used to reduce their formation.

Animals↗
PubMed1997

The case of low-dose aspirin for the prevention of myocardial infarction: but how low is low?

Although there is firm consensus that aspirin reduces the incidences (and severity) of reinfarction if given to patients after a myocardial infarction or in patients with unstable angina, there is disagreement about the optimum dose that should be used. We make the case that it could be considerably lower than the "medium dose" (75-320 mg daily) in current usage and put forward the view that a dose of 30 mg daily is sufficient. The arguments are based on the presystemic, exclusively pharmacokinetic inhibition of thromboxane synthesis in platelets by very low-dose aspirin and the importance of maintaining prostacyclin production by endothelial cells. Little attention has been in the past to the endogenous myocardial protection that results from prostacyclin generation. Such low doses have the additional advantage of not inducing gastrointestinal ulceration. We conclude that more extensive clinical trials with such "low-dose" aspirin preparations are warranted.

Aspirin↗
PubMed1997

Therapeutic use of the 193-nm excimer laser in corneal pathologies.

PURPOSE: To analyze the results of phototherapeutic keratectomy. PATIENTS AND METHODS: We performed 193-nm excimer laser phototherapeutic keratectomy (PTK) in 252 eyes of 216 patients suffering from pain and/or decrease in visual acuity. One hundred and three eyes had recurrent erosions of the cornea, 86 eyes underwent excimer laser smoothing of the cornea after pterygium surgery, 29 eyes had a bandlike keratopathy (25 rough, 4 smooth) and 34 eyes had other pathologic conditions such as amyloidosis of the cornea, anterior corneal dystrophies, scars after injuries, alkali burns, superficial stromal dystrophies and infections. Recurrent erosions and epithelial dystrophies were treated with 15-20 pulses (160-200 mJ/cm2, 8 mm ablation zone) after mechanical abrasion of the epithelium. Removal of corneal opacities and scars required the use of a masking fluid (methyl-cellulose) in different concentrations and slit-lamp control (integrated in the delivery system of the excimer laser). RESULTS: Some 91% of the eyes with recurrent erosions were recurrence-free. Fifty-two per cent of the eyes with pterygium had recurrences if the baresclera technique was used and 33% of the eyes if a free conjunctival graft was used. The difference was not significant. All of the patients with bandlike keratopathy were pain-free. In 88% of the eyes with special indications the treatment goal was achieved. No positive effect was seen after alkali burn, in a patient with anterior membrane dystrophy (Grayson-Wilbrandt corneal dystrophy) or in a patient with a corneal protuberance. In one patient with scleroperikeratitis a late recurrence of the opacity was observed 3 years after surgery. A loss of best corrected visual acuity was found only in one patient with bullous keratopathy in whom the treatment goal was the reduction of pain. All patients with smooth bandlike keratopathy had an improvement in best corrected visual acuity of at least one line. About 70% of patients with special indications improved by at least one line, up to nine lines. A possible hyperopic shift in all groups could be minimized using a large ablation zone. CONCLUSION: PTK with the 193-nm excimer laser is a safe and effective treatment for many superficial diseases of the cornea.

Adolescent↗
PubMed1997

[Lacrimal duct surgery in childhood. Retrospective study at the Munster University Ophthalmology Clinic].

UNLABELLED: Surgery on the lacrimal system in 296 children was performed at the Münster University Eye Hospital from 1987 to 1992. PATIENTS AND METHODS: The age of the patients, etiology of the obstruction and surgical strategy were analyzed retrospetively. A questionnaire was sent to the parents to allow evaluation of the results and subjective satisfaction. RESULTS: A total of 181 questionnaires was sent back to our hospital (results of 210 operations, including 24 preoperations). Of the 124 children were up to 3 years old. 197 obstructions were congenital, 7 traumatic, 4 results of inflammation, and 2 iatrogenic. In 184 patients we performed intubation with silicon tubing. Seven patients had canalicular surgery, and 19 patients had dacryocystorhinostomy (DCR). After intubation 87.5% of patients were practically without complaints, after canalicular surgery 85.7% and after DCR 78.9%. Five patients suffered from severe problems and had to be reoperated.

Child, Preschool↗
PubMed1997

Fluence and mutagenic side effects of excimer laser radiation applied in ophthalmology in human lymphocytes in vitro.

PURPOSE: To investigate the influence of different fluences in 193 and 248 nm excimer laser radiation on the yields of chromatid and chromosome aberrations induced in human lymphocytes in vitro. METHOD: Heparinized human blood was exposed to 193 or 248 nm excimer laser radiation. The fluence was gradually increased from 21 to 400 mJ/cm2 in 193 nm (constant total energy of 250 J) and from 150 to 377 mJ/cm2 in 248 nm radiation (constant total energy of 500 J). Chromatid and chromosome aberrations were then analysed microscopically. RESULTS: The yields of chromatid breaks and achromatic lesions depend on the fluence per pulse. This dependence contains a linear component, indicating a threshold of about 70 mJ/cm2 fluence in 193 nm and of about 250 mJ/cm2 fluence in 248 nm laser radiation. An increase of the yield of dicentric chromosomes could only be observed at the highest fluence tested (377 mJ/cm2) in the 248 nm series. Over 126 mJ/cm2 in 193 nm radiation no lymphocytes could be cultured and therefore no aberrations could be found. CONCLUSIONS: Our findings show that the fluence of 193 nm and of 248 nm excimer laser radiation has an effect on the yields of chromatid breaks and achromatic lesions in human lymphocytes under in vitro conditions.

Adult↗
PubMed1996

Corneal haze after mechanical debridement for overcorrection after myopic photorefractive keratectomy.

A 47-year-old man had photorefractive keratectomy (PRK) to correct myopia. Three months after surgery he was slightly overcorrected with +1.25-0.5/170 degrees. He then suffered a gout attack and showed a refraction of +2.5-0.5/4 degrees which decreased to +1.75-0.5 degrees. To reduce this permanent overcorrection we performed mechanical debridement of the corneal epithelium. the patient had haze grade 2-3 after 2 weeks and haze grade 0-1 some 4 months later. The refraction was +1-0.5/25 degrees. This case report indicates that mechanical debridement is able to reduce overcorrection after PRK and bears a risk of haze formation comparable to that associated with PRK.

Corneal Diseases↗
PubMed1995

Correcting myopic astigmatism with an areal 193 nm excimer laser ablation.

A new system to correct symmetric bow-tie myopic astigmatism with the excimer laser using oval apertures for toric ablations is described. Initial results in two patients who had -5.0 and -5.5 diopters of astigmatism after surgery with six-months follow-up showed a reduction of up to 85% with a minimal axial error of two degrees.

Aged↗
PubMed1995

[Unilateral tucking and advancement of the inferior oblique muscle for treatment of A-pattern strabismus].

PATIENTS: The clinical results of the unilateral tucking and advancement of the inferior oblique base on the retrospective data of 81 patients. METHOD: Tucking and advancement of the inferior oblique was used in A-pattern strabismus, which showed a marked hypofunction of the inferior oblique in relation to hyperfunction of the superior oblique. RESULTS: The unilateral tucking and advancement of the inferior oblique improves the incomitance as well as the elevating deficiency in adduction. The effect of the operation relative to incomitance depends on its preoperative state. With increasing A-pattern strabismus has an increased effect of the advancement and tucking is revealed. CONCLUSION: Unilateral tucking and advancement of the inferior oblique is not a routine procedure in the treatment of A-pattern strabismus, but it is possible to improve the incomitance and the elevating deficiency in adduction.

Adolescent↗
PubMed1995

[Special indications for photorefractive (PRK) and phototherapeutic (PTK) excimer laser keratotomies. A presentation of 5 cases].

Five patients with specific indications for photorefractive and phototherapeutic keratectomy (PRK and PTK) by excimer laser at 193 nm were treated successfully: they had presented with epithelial dystrophy of the cornea, amyloid, von Szilly's scleroperikartitis, myopia after cataract extraction and before secondary implantation of an intraocular lens in the other eye, and myopia. In all cases it was possible to avoid extensive surgical procedures such as lamellar keratoplasty or intraocular lens exchange. There were no recurrences in the patients with superficial corneal diseases, and the patients who had undergone PRK were within 0.25 Dpt of the target acuity. The follow-up was between 8 months and 1 year.

Adult↗
PubMed1995

[Excimer laser phototherapeutic keratectomy (PTK) and modified bare sclera technique for treatment of pterygium].

Forty-six pterygia were surgically removed using a modified "bare sclera" technique. Additionally, an excimer laser PTK was performed using the immersion method to smooth the irregular surface of the cornea. Follow-up was 6 to 10 months. We found 24 recurrences. In patients with pterygia of more than 4 mm who were from southern Europe, the Middle East, or Africa, the recurrence rate was 100%. In pterygia from 2 to 4 mm the recurrence rate was 50%; in pterygia up to the limbus no recurrences were noted. The excimer laser has no positive influence on pterygia recurrences that have been removed using the modified "bare sclera" technique.

Adult↗
PubMed1995

[Prevention of reinfarction with 100 mg or 30 mg ASS daily?].

The prevention of heart infarction with 100 mg aspirin is common practice in Germany, in spite of the fact that it is based on only two small studies, the results of which are not generalized. Over 14 years, several experimental and clinical studies have shown that 20-30 mg aspirin/d for pharmacokinetic reason selectively inhibit the thromboxane synthesis while the endogenous prostacyclin synthesis remains intact. Prostacyclin plays an important cardioprotective role for the ischemic heart, having antiplatelet and antifibrillatory effects, potentiates the antiplatelet effect of the nitrovasodilators and nitric oxide, and increases the release of adenosine. A superior preventive action and lower side effects of 30 mg/d aspirin in direct comparison with higher doses was first proved by the Cottbus reinfarction study. The 30 mg aspirin tablet per day ought to replace the present prevention with higher doses.

Animals↗
PubMed1994

Measurement of elastic modulus of the central bovine cornea by means of holographic interferometry. Part II. Results.

BACKGROUND: The structural and elastic properties of the cornea play an important role in the outcome of corneal refractive surgery. A way to describe the elastic properties is to calculate Young's modulus. The tangent Young's modulus (Eit) represents the first part of the viscoelastic response of the intact cornea due to intraocular pressure increase. METHOD: The tangent Young's modulus (Eit) of the central cornea of 16 fresh enucleated intact bovine eyes determined from the immediate response was calculated by means of holographic interferometry. The stress was an increase of the intraocular pressure. In 16 eyes the change of intraocular pressure was 10 Pa (group I), starting with an intraocular pressure of 1340 Pa (about 10 mm Hg). In 6 of these 16 eyes there was a second pressure increase of 20 Pa starting at the same intraocular pressure of 1340 Pa (about 10 mm Hg) (group II). RESULTS: The mean value for the Young's modulus in group I was 1.58 x 10(5) Pa. For group II the Young's modulus was 1.60 x 10(5) Pa. The difference was not significant. The values for the Young's moduli of the cornea of intact eyes are about 100 times smaller than calculations based on experiments with strips of the cornea. CONCLUSION: It is necessary to consider the localization of the corneal tissue to avoid influences of corneal hydration or dehydration and to define the existing intraocular pressure if Young's modulus of the cornea is to be calculated.

Animals↗
PubMed1994

Establishment and characterization of two Merkel cell tumor cultures.

Two Merkel cell tumor cultures (MC-MA1, MC-MA2) have been established from metastases of typical Merkel cell tumors. The mestastases in vivo were characterized by co-expression of cytokeratins 8, 18, 19, 20 and neurofilaments, presence of intermediate filament whirls, expression of synaptophysin, neuron-specific enolase, and chromogranin A, rare and weak immunostaining for plakoglobin but absence of cadherins and desmoplakins. Both cultures grow, using supplemented RPMI medium on human irradiated fibroblast feeder layers, as loosely arranged floating small aggregates. Their karyotypes are mostly hyperdiploid. The mean doubling times were about 84 h in the first 8 months and later increased. Ultrastructural and immunoelectron microscopic studies of the Merkel cell tumor cells in vitro (MC-MA1, MC-MA2) revealed sparse membrane-bound neuroendocrine granules and typical IFs that were partly arranged in paranuclear whirls and were labeled by antibodies against cytokeratins and neurofilaments. In immunocytochemical studies using antibodies to cytokeratins 8, 18, 19, and 20 and neurofilament protein NF-L, Merkel cell tumor cells in vitro showed a uniform staining appearing as paranuclear whirls and cytoplasmic fibrils as well. Double-labeling experiments showed a co-localization of both intermediate filament types in most cells. Biochemically we found cytokeratins 8, 18, 19, and 20, and NF-L in tumor cells in vitro. Immunocytochemical staining was negative for desmoplakins, various cadherins, and cell adhesion molecules, whereas plakoglobin was only rarely detectable in some Merkel cell tumor cells in vitro. By immunoluminometric assay chromogranin A was detected in cell homogenates and culture supernatants as well. Immunocytochemically, synaptophysin and neuron-specific enolase were detectable additionally in some of the cells. These established cell cultures will allow further studies devoted to the biology, differentiation, and hormone secretion of Merkel cell tumors that may also increase our knowledge about normal Merkel cells.

Aged↗
PubMed1994

[15 months photorefractive keratectomy at the Munster University Eye Clinic].

We performed a photorefractive keratectomy (PRK) in 51 myopic eyes of 34 patients. Cortisone-responders were excluded. All patients were unable to tolerate contact lenses. The intended correction was between -1.75 and -7.0 D. None of the patients demonstrated a decrease in visual acuity at its highest level of correction. The maximum haze was +1. No eye had to be reoperated upon. Nine months after PRK, the maximum deviation from the intended correction was 2 D in a -6.5 D correction. After 12 months, however, we found a regression of 2 D without signs of keratoconus or increase of haze in 2 patients.

Cornea↗
PubMed1994

[Syngeneic transplantation of nasal mucosa and azathioprine medication for therapy of cicatricial ocular mucous membrane pemphigoid. Study of 9 patients with 11 eyes].

Nine patients (11 eyes) with ocular cicatricial pemphigoid were treated with systemic azathioprine and a syngeneic nasal mucosa transplant from the inferior turbinate. Follow-up was 8-26 months (average 15 months). Grafting was successful in all cases. Treatment ameliorated the symptoms of pain in all patients and double vision in one. In 2 eyes in which simultaneous pannus resection had been performed, neither pannus nor corneal vascularization recurred. Late complications were recurrences with symblephara in two cases when azathioprine was stopped; in one patient with a serpiginous ulcer tectonic penetrating keratoplasty à chaud had to be performed; and in another a trophic ulcer was healed with a therapeutic contact lens.

Aged↗