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Biomedical subjects

B Wiechens

Publications and source records attributed to B Wiechens.

At least 19 recordsLinked to original sources
PubMed2003

[Pars plana vitrectomy in cystoid macular edema of different forms of chronic uveitis].

BACKGROUND: Cystoid macular edema (CME) is a common complication in different forms of chronic uveitis. In spite of immunosuppressive and anti-inflammatory therapy, chronic or relapsing courses can occur which may have a negative impact on visual prognosis. Pars plana vitrectomy (PPV) is known to positively influence chronic uveitis. This retrospective study was performed to investigate the role of PPV in the therapy refractive uveitic CME. PATIENTS AND METHODS: PPV for CME was performed in eyes with CME in intermediate uveitis (IMU, n=42), chronic iridocyclitis in juvenile rheumatoid arthritis (CIC, n=14) and multifocal chorioretinitis (MFC, n=12). In none of the eyes had immunosuppressive and/or anti-inflammatory therapy or anti-edema treatment (e.g.acetazolamide) led to regression of the CME. After a postoperative follow-up period of 7 and 106 months all patients were re-examined. RESULTS: Postoperative complete or partial regression of CME was observed as follows: IMU: 25/42 (59.5%), CIC: 8/14 (57.1%),MFC: 5/12 (41.7%). A significant increase in visual acuity of 2 lines and more was observed in 50%,71.4% and 41.7% of eyes, respectively. In the long-term follow-up best functional results were achieved in eyes with IMU. CONCLUSIONS: Response to PPV was variable according to the type of underlying form of uveitis. The lowest success rate could be observed in eyes with MFC. Although the postoperative regression rate of CME was satisfactory in eyes with CIC, long-term visual acuity results were disappointing due to secondary complications of CIC in this young age group. Best results were achieved in patients with IMU (statistically not significant). A multicenter study in a larger series of patients is needed to investigate the exact role of PPV in different forms of chronic uveitis.

Adolescent↗
PubMed2001

Pars-plana vitrectomy in cystoid macular edema associated with intermediate uveitis.

BACKGROUND: Cystoid macular edema (CME) is a common complication in the course of intermediate uveitis. In spite of systemic therapy with steroids or carbonic anhydrase inhibitors, persistence of CME is observed. Pars plana vitrectomy (PPV) is known to influence the course of intermediate uveitis positively. The present study was performed to investigate the role of PPV in the therapy of CME in intermediate uveitis. MATERIALS AND METHODS: Forty-two eyes of 32 patients were re-examined after PPV for CME. In all eyes fluorescein angiography was performed. Average age at the time of surgery was 31.9 years (range 6-64 years). All patients had received systemic corticosteroid and/or immunosuppressive treatment during the course of their disease. In some patients systemic therapy with carbonic anhydrase inhibitors was performed. The mean duration of postoperative follow-up was 20.2 months (range 6-102 months). RESULTS: Preoperative visual acuity (VA) in all eyes was between 1/10 and 0.5. Total regression of CME after surgery was observed in 18 of 42 eyes (42.8%), partial improvement in 7 eyes (16.7%). In 13 of 42 eyes (30.9%) the CME remained unchanged. Twenty-one of 42 eyes (50.0%) experienced a postoperative improvement of VA of 2 lines or more. In 18 of 42 eyes (42.8%) there was no change; in 3 eyes (7.2%) VA was less. In the long-term follow-up the corresponding results were slightly worse (17/17/8 eyes) due to secondary complications. In the majority of patients systemic medical therapy could be reduced or discontinued. CONCLUSION: Pars-plana vitrectomy led to regression of CME in 59% of cases and to subsequent improvement of VA in 50% of eyes with intermediate uveitis. PPV should be considered soon after medical therapy has been shown to be ineffective.

Adolescent↗
PubMed2000

[Differential diagnosis of sinugenic enophthalmos].

BACKGROUND: Spontaneous enophthalmos without recent trauma is a rare condition. Its origin is difficult to evaluate. METHOD: Specific properties of this symptom complex are presented based on a literature review and on case reports. Possible connections between enophthalmos and paranasal sinus diseases as well as differential diagnoses are analysed. PATIENTS: 1. 31 year old female patient with right spontaneous enophthalmos and no history of trauma. CT-imaging disclosed tissue formation in the maxillary sinus, partially destroyed medial orbital wall and floor, descended orbital contents following Caldwell-Luc procedure several years previously. After endonasal surgery of ethmoidal and maxillary sinus with removal of a large cyst good functional and cosmetical result. 2. 25 year old male patient complaining of pain in the periorbital region, presenting with left enophthalmos and superonasal deviation of the eyeball. MRI and CT revealed a tumor in the orbital floor region with total destruction of the roof of the maxillary sinus. Removal of the tumor by a combined lateral rhinotomy and subciliary approach. DIAGNOSIS: Leiomyoma. Orbital reconstruction with PDS-sheet. Postoperatively, improved globe position and motility. No recurrence during three year follow-up. CONCLUSION: When evaluating the causes of enophthalmos, chronic diseases of the paranasal sinuses or their walls must be considered. Surgical therapy is promising.

Adult↗
PubMed1999

[Severe intra- and postoperative supra-choroid hemorrhage. Risk factors, therapy, results].

BACKGROUND: The aim of this study was to analyze risk factors, therapeutic strategies, and functional and anatomic results of eyes with severe suprachoroidal hemorrhage. PATIENTS: Eight of 11 bleeding episodes occurred intraoperatively and 3/11 postoperatively. Bleeding was associated with the following surgical procedures: perforating keratoplasty (5x), extracapsular cataract extraction (3x), pars plana vitrectomy (2x), intracapsular cataract extraction (1x). RESULTS: Nine operations were performed with general anesthesia, two after retrobulbar injection. Ocular risk factors (e.g., prior operations, ocular diseases) and general risk factors (e.g., cardiovascular diseases, diabetes) were analyzed. At the end of the follow-up time visual acuity had improved in three eyes, and it was unchanged in one eye and worse in seven eyes. Four eyes were amaurotic; two of them had to be enucleated. CONCLUSIONS: In spite of using state-of-the-art surgical techniques the prognosis of suprachoroidal bleeding remains serious. Patients who have a combination of several ocular and general risk factors almost exclusively are the ones who afflicted by this complication.

Adult↗
PubMed1999

Quantification of intraocular retained perfluorodecalin after macroscopic complete removal.

BACKGROUND: A study was performed to determine the amount of intraocular retained perfluorodecalin after macroscopic complete removal. MATERIAL AND METHODS: Freshly enucleated pig eyes had the anterior segment removed, vitrectomy was carried out, and the eye cups were placed in 0.9% buffered saline solution. One millilitre of perfluorodecalin was instilled for 30 min, followed by a fluid-air exchange. Perfluorodecalin was macroscopically removed. The retina was rinsed twice with 0.9% buffered saline solution. In a second group no rinsing was done, while in a third group no fluid-air exchange was performed. Finally all eye cups were filled with 2.0 ml of the perfluoropolyether Hostinert 130 to dissolve retained perfluorodecalin. The quantity of perfluorodecalin in perfluoropolyether was determined by gas chromatography. RESULTS: Retained perfluorodecalin was detected in all experiments. The smallest portion of perfluorodecalin retained (range 0.04-0.08, mean 0.058%, SD +/- 0.015%) was observed without fluid-air exchange. After fluid-air exchange the portion with rinsing was 0.11-0.27% (mean 0.21%, SD +/- 0.059%) and that without rinsing was 0.51-0.69% (mean 0.60%, SD +/- 0.065%). CONCLUSIONS: Even after macroscopic complete removal of perfluorodecalin a thin layer remains on the retina. If intraoperative fluid-gas exchange is necessary, multiple rinsing with 0.9% buffered saline solution should be performed to reduce the amount of perfluorocarbon liquid retained.

Animals↗
PubMed1999

Iris angiographic changes in multifocal chorioretinitis with panuveitis.

BACKGROUND: Multifocal chorioretinitis with panuveitis (MCP) is a chronic inflammatory disease of the peripheral retina and choroid with typical clinical appearance. Although obvious involvement of the anterior segment is often mild, severe chronic inflammatory reactions can occur after cataract surgery. Explantation of an intraocular lens (IOL) or primary aphakia may be necessary. In this pilot study we therefore examined the iris of patients with MCP by means of fluorescein angiography (IAG) to investigate iris vessel involvement. MATERIALS AND METHODS: Twenty-one eyes of 13 patients with MCP (12 women, 1 man) were examined by IAG. The average age of the patients was 72.5+/-6.2 years, and the average duration of the disease prior to examination was 13 months. In 9 of 21 eyes a pars plana vitrectomy (PPV) was performed because of marked vitreous opacification. IAG was performed before and after surgery. RESULTS: Although clinically unremarkable the iris of 14/21 eyes showed avascular zones in IAG; 13/21 had irregular vessels such as vascular collaterals, and 10/21 exhibited neovascularization. All eyes showed leakage of dye at the pupillary margin, and in 15/21 there was leakage out of peripheral iris vessels. In 2 of 9 eyes angiographic changes such as avascular zones regressed after PPV. CONCLUSION: Irides in patients with MCP that are unremarkable on slit-lamp examination may show marked angiographic changes. Thus IAG in those cases with planned cataract extraction and IOL, if necessary combined with PPV for vitreous opacification, may be warranted in order to better assess the prognosis after surgery.

Aged↗
PubMed1999

Experimental intravitreal application of ciprofloxacin in rabbits.

BACKGROUND: Ciprofloxacin (CFLX) is a fluoroquinolone antibiotic with a broad antimicrobial spectrum. This study was performed to examine the retinal toxicity of free and liposome-incorporated CFLX in rabbit eyes after intravitreal injection. MATERIALS AND METHODS: Free CFLX in doses of 100, 250, 500, 1,000 and 2,000 microg was injected into the midvitreous of rabbit eyes (n = 28). To prolong the intravitreal antibacterial level, CFLX was incorporated into multilamellar liposomes: 0.1 ml of this suspension ( wedge 273.6 microg CFLX) was injected into the midvitreous of a second group of rabbit eyes (n = 6). The other eye served as a control and received normal saline solution or empty liposomes, respectively. Before injection and at the end of follow-up an electroretinogram (ERG) was obtained. After a follow-up of 1, 14 and 28 days the animals were perfused with glutaraldehyde and the eyes were examined by light and transmission electron microscopy. RESULTS: Significant reduction of the ERG was observed after 2,000 microg free CFLX in 4 out of 6 eyes after 14 days. Fourteen days after injection of 2,000 microg CFLX the central retina showed pigmentary changes in 4 out of 6 eyes. In the second group the ERG as well as the histologic studies did not reveal any pathologic changes after injection of liposome-incorporated CFLX compared to the control eyes. CONCLUSION: In therapeutic doses of 100-500 microg, free CFLX does not have retinal toxicity in rabbit eyes. No retinal toxicity was observed after intravitreal injection of liposome-incorporated CFLX.

Animals↗
PubMed1999

Primary orbital leiomyoma and leiomyosarcoma.

A case of an extremely rare primary orbital leiomyoma in a 25-year-old male patient is presented who had a lifelong history of deviation of the left eye globe with slight enophthalmos and reduced motility. Because of pain and increasing deviation of the eye the tumor was totally resected. On histologic examination the tumor showed ossification which is extremely rare so that a calcifying fibroma had to be ruled out. In immunohistochemistry, however, this tumor stained with smooth muscle antigen. Less than 2% of cells stained positive for Ki-S1, a proliferation marker. The second case is a rare primary orbital leiomyosarcoma in an 84-year-old female patient that showed massive growth. After exenteration histologic examination showed a dedifferentiated highly malignant soft tissue tumor which expressed desmin and smooth muscle actin but was negative for myoglobin, S-100 and HMB-45.

Adult↗
PubMed1998

Scanning electron microscopic findings on intraocular metallic foreign bodies.

BACKGROUND: The study reported here was performed to investigate morphologic intraocular reactions on the surface of metallic intraocular foreign bodies (IOFB) with scanning electron microscopy. METHODS: Twenty-seven extracted IOFB were investigated. Of these, 22 were situated in the vitreous body; 19 had contact with the retina. Five IOFB had been removed from the anterior segment (control group). The duration of intraocular retention was 6 h to 24 days. Immediately after microsurgical removal the IOFB were fixed, dehydrated, dried, sputter-coated and investigated with a scanning electron microscope. Two IOFB from the vitreous were treated for collagen preservation. RESULTS: Eighteen of 20 intravitreal IOFB showed fibers of fibrin on its surface; 11 of 20 were covered with a homogeneous layer. Within this layer a net of collagen fibers was detectable. A major cellular reaction was observed only on IOFB that injured the retina, pigment epithelium and choroid. CONCLUSIONS: This morphologic study shows that: (1) a fibrin net develops in the vitreous around intravitreal IOFB; (2) depositions of amorphous material into the spaces of this net lead to dense coverage of the IOFB; (3) cellular reactions are not condition for the development of this coverage; (4) laceration of the retina induces a fibrocellular response.

Adolescent↗
PubMed1998

[Clearance of liposome-incorporated ciprofloxacin after intravitreal injection in rabbit eyes].

BACKGROUND: Ciprofloxacin (CIP) is a fluoroquinolone-antibiotic with a high antimicrobial activity against all pathogens causing bacterial endophthalmitis. After intravitreal injection, however, elimination half-life of this antibiotic is only 2.2 hours. To prolong intraocular bioavailability this study was performed to incorporate CIP into liposomes and to determine its clearance from the vitreous after intravitreal injection. MATERIALS AND METHODS: CIP was incorporated into multilamellar vesicles by mechanical dispersion. 0.1 ml of this suspension (equiv. 273.6 micrograms CIP) was injected into the midvitreous of pigmented rabbit eyes (Chinchilla-bastards). One day, 3 and 14 days after the injection intravitreal concentration of CIP was determined by means of high-pressure-liquid-chromatography after dissolution of the liposomes by ultrasound. At the same intervals serum concentration of the antibiotic was examined as well. RESULTS: Within 24 hours intravitreal concentration fell to 18.0 micrograms/ml. Three days after the injection the concentration of CIP was 6.9 micrograms/ml. This is still above the minimal inhibitory concentration (MIC90) of the most common ocular pathogens. At 14 days CIP was not detectable in the vitreous any more. The serum concentration was between 0.04 microgram/ml and 0.07 microgram/ml. 3 and 14 days after injection no CIP could be detected. CONCLUSIONS: This study shows that the incorporation of CIP into liposomes can be achieved in sufficient doses by mechanical dispersion method. After intravitreal application the bioavailability of the antibiotic can be markedly improved. Even after 3 days the intravitreal levels were above the MIC90 of the most common endophthalmitis pathogens.

Animals↗
PubMed1998

Long-term results after scleral buckling surgery in uncomplicated juvenile retinal detachment without proliferative vitreoretinopathy.

PURPOSE: To evaluate long-term anatomic and functional results of scleral buckling surgery in retinal detachment without proliferative vitreoretinopathy in juvenile patients. METHODS: A total of 33 eyes of 31 patients were operated on. Surgical techniques included segmental buckle (23 eyes), radial buckle (5 eyes), encircling band (4 eyes), and temporary balloon buckle (1 eye). The average age at time of surgery was 15.3 years and the average follow-up time was 8.9 years. Retinal detachment was associated with the following risk factors: myopia (14 eyes), blunt trauma (8 eyes), and aphakia (3 eyes). In 9 eyes, no risk factors were present. Fifteen eyes had a detached macula. In addition to anterior and posterior segment examination, binocular functions and ocular motility were evaluated. RESULTS: Retinal reattachment required one operation in 29 eyes, two operations in three eyes, and three operations in one eye. In one eye, pars plana vitrectomy had to be performed to reattach the retina. At the end of follow-up, retinal reattachment was achieved in all eyes. Visual acuity of 20/40 or better was achieved by 39.4% preoperatively and 60.6% postoperatively; in 52.4%, binocular functions were normal. CONCLUSION: Scleral buckling procedures allow favorable anatomic and functional results in juvenile retinal detachment without proliferative vitreoretinopathy.

Adolescent↗
PubMed1998

Ultrasound biomicroscopic imaging in intermediate uveitis.

BACKGROUND: Clinical examination of the region of the eye mainly affected in patients with intermediate uveitis is difficult and often hampered by media opacities. In that perspective ultrasound biomicroscopy (UBM) promises to be a valuable additional diagnostic tool. METHODS: UBM was performed at a sound frequency of 50 MHz on 26 eyes of 13 patients with intermediate uveitis in order to determine configuration of pars plana, peripheral retina, and vitreous. Findings of ophthalmoscopy with scleral indentation and UBM were compared. RESULTS: In 18 of 26 eyes pathological structures such as membraneous or fluffy vitreous condensations were identified by UBM. Among these UBM revealed pathological findings which were not visible on funduscopy in nine eyes. Most importantly, vitreoretinal adhesions with traction on the retina were imaged in four eyes. However, in three eyes vitreous opacities being visible on funduscopy were not identified by UBM. CONCLUSION: UBM seems to be a valuable diagnostic technique for the evaluation of patients with intermediate uveitis. Longitudinal studies will have to determine the relevance of UBM findings for the individual clinical course and their influence on therapeutic decisions.

Adolescent↗
PubMed1997

Primary antiphospholipid antibody syndrome and retinal occlusive vasculopathy.

PURPOSE: To report a 31-year-old healthy patient with retinal venous occlusion in his left eye attributable to primary antiphospholipid antibody syndrome. METHODS: The patient was examined clinically. Multiple serologic and clinical investigations were performed to determine the causative disease. He was closely followed up for more than 3 years. RESULTS: The presence of lupus anticoagulant in our patient was indicated by a kaolin clotting time index of 27 (normal, <17) and confirmed by the demonstration of IgG antibodies against phospholipids. After long-term oral anticoagulant treatment for 2 years, lupus anticoagulant levels returned to normal, and therapy was stopped. No further thrombotic event occurred during follow-up. CONCLUSIONS: In retinal vascular occlusions of unexplained origin, antiphospholipid antibodies may play an important role in the pathogenesis. Detecting these antibodies in the serum of patients with retinal vascular occlusion helps determine the appropriate treatment with long-term oral anticoagulants.

Adult↗
PubMed1997

[Intraoperative skiascopy for determining the refractive value of an implantable intraocular lens].

BACKGROUND: Preoperative biometry for calculation of the refractive power of intraocular lenses is not sufficiently reliable in certain cases. Most frequently inaccuracies tend to occur in highly myopic eyes. Preceding refractive procedures can also impair IOL-calculation or even make it impossible. PATIENTS: In a highly myopic patient IOL-power calculation was not possible with conventional calculation formulas due to a preexisting refractive silicone lens located between the cataractuous natural lens and the iris. In another myopic patient ultrasound measurement of axial eye length produced variable and unreliable results. Therefore retinoscopy was performed intraoperatively in the aphakic eye. Refractive power of the IOL was calculated using a new formula. For validation of the method retinoscopy was performed intraoperatively in a second group of 11 patients with unproblematic ultrasound biometry. RESULTS: In 3 eyes IOL power was chosen according to intraoperative retinoscopy. A maximal deviation of 1.25 D from the aimed refraction resulted. In the second group, the retinoscopic method produced partially considerably inaccurate results as compared to the ultrasound biometry. Inaccuracies increased with the extent of hyperopia. CONCLUSIONS: In cases of difficult or inaccurate preoperative ultrasound biometry IOL power can be estimated after intraoperative retinoscopy in the aphacic highly myopic eye. IOL power can be calculated instantly using computer programs or tables. This method additionally enables the surgeon to control the refractive result of intraocular lens implantation prior to wound closure. However this method lacks reliability in higher hyperopic eyes, as in these cases small changes in corneal vertex distance of the lens used for retinoscopy highly alter the result.

Adult↗
PubMed1996

[Macular combined malformation (hamartoma) of the retina and retinal pigment epithelium].

BACKGROUND: Combined malformations (hamartomas) of the retina and the retinal pigment epithelium are extremely rare. Confusion of these pigmented lesions with choroidal melanomas or other malignancies is possible. MATERIALS AND METHODS: We present the cases of a 7-year-old girl who developed accommodative convergent strabism and the case of an 8-year-old boy with deterioration of visual acuity in the left eye. On examination the anterior segments were normal in both cases. Funduscopically both eyes showed a centrally located large, partly pigmented and slightly prominent tumor, which extended fanlike into the normal-appearing retina. Both lesions were partly obscured by grayish-white, semitranslucent and thickened retina with retinal folds and overlying tortuous vessels. On follow-up examination one lesion seemed to be slightly more pigmented whereas the other lesion remained unchanged. RESULTS AND DISCUSSION: Combined malformations of the retina and the retinal pigment epithelium were originally described as clinical entities (hamartomas) by Gass in 1973. A few additional cases were subsequently published by McLean in 1976, by Laqua and Wessing in 1979 and some other authors. Laqua and Wessing were the first to give a report of a histologic study in one case with a macular lesion that showed two distinguishable components. The outer pigmented portion consisted of hypertrophied retinal pigment epithelium; the inner unpigmented portion consisted of a malformed and thickened retina which, however, showed normal layering. The clinical characteristics are usually diagnostic. Fluorescein angiography is helpful in establishing the diagnosis and ruling out differential diagnoses. CONCLUSION: Although long-term follow-up did not show evidence of growth patients with combined malformation of the retina and retinal pigment epithelium should be followed up regularly.

Child↗
PubMed1996

[Chronic granulomatous chorioretinitis in tuberculosis].

BACKGROUND: Though the incidence of tuberculosis decreased substantially during the second half of the century, a steady increase of new cases has been observed within the last decade. Among other reasons, the growing number of immunodeficient patients (e.g. HIV, therapy with immunosuppressive agents) and migration from underdeveloped to industrial countries contribute to this finding. PATIENT: A 57-year-old male patient presented with a history of chronic bilateral chorioretinitis of unknown origin. During the last months a marked decrease in visual acuity of the left eye was noted. Prior diagnostic attempts had not led to a specific diagnosis. Notable was the history of long-term systemic corticosteroid therapy for chronic obstructive lung disease. Funduscopy of the right eye revealed a choroidal granuloma with adjacent serous retinal detachment. Both eyes showed multiple dot-like lesions in the retinal pigment epithelium of the posterior pole. Finally the diagnosis could be made by isolating Mycobacterium tuberculosis from sputum samples and gastric aspirate. Within a few weeks after starting tuberculostatic therapy the ocular symptoms regressed and the visual acuity improved significantly. DISCUSSION: Securing the diagnosis of tuberculous uveitis is often difficult. The differential diagnosis includes other granulomatous ocular inflammations. The detection of Mycobacterium tuberculosis and the clinical course make the diagnosis most likely. CONCLUSION: Tuberculosis should always be included in the differential diagnosis as a possible etiology for uveitis, particularly in those cases taking a chronic course. Despite the recent emergence of drug-resistant strains in most cases tuberculosis is a well curable disease.

Chorioretinitis↗
PubMed1996

Circular surgical cyclopexy after extensive traumatic cyclodialysis.

The authors operated on a patient who had bilateral ocular hypotony after severe blunt ocular trauma with subsequent circular cyclodialysis and luxation of the lenses. Because of the specific situation, none of the previously reported procedures could be applied. A new surgical technique was used to circularly refixate the ciliary body ab interno. The method described here is simple and can be recommended as an alternative technique to refixate the ciliary body in all aphakic or pseudophakic eyes with persistent ocular hypotony caused by traumatic or surgically induced cyclodialysis.

Adult↗