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N Bornfeld

Publications and source records attributed to N Bornfeld.

At least 73 records · Page 4Linked to original sources
PubMed1998

Expression patterns of cyclin D1 and related proteins regulating G1-S phase transition in uveal melanoma and retinoblastoma.

BACKGROUND/AIMS: A checkpoint mechanism in late G1, whose regulation via loss of retinoblastoma protein (pRB) or p16, or overexpression of cyclin D1 or cyclin dependent kinase 4 (CDK4), has been proposed to constitute a common pathway to malignancy. The aims of this study were (a) to compare markers of cell cycle G1-S phase transition in an intraocular tumour with known pRB deficiency (retinoblastoma) and compare it with one with an apparently functional pRB (uveal melanoma); (b) to determine if one of these markers may have a role in the pathogenesis of uveal melanoma; and (c) to determine if there is a difference in cell cycle marker expression following treatment of uveal melanoma and retinoblastoma. METHODS: 90 eyes were enucleated from 89 patients for retinoblastoma (n = 24) or for choroidal or ciliary body melanoma (n = 66). Conventional paraffin sections were assessed for cell type and degree of differentiation. Additional slides were investigated applying standard immunohistochemical methods with antibodies specific for cyclin D1 protein, pRB, p53, p21, p16, BCL-2, and MIB-1. RESULTS: Cyclin D1 protein and pRB were negative in retinoblastoma using the applied antibodies. In contrast, cyclin D1 protein expression was observed in 65% of uveal melanomas; a positive correlation between cyclin D1 cell positivity and tumour cell type, location, growth fraction, as well as with pRB positivity was observed. p53, p21, and p16 could be demonstrated in both tumours. An inverse relation between p53 and p21 expression was demonstrated in most choroidal melanomas and in some retinoblastomas. Apart from a decrease in the growth fractions of the tumours as determined by MIB-1, a significant difference in the expression of G1-S phase transition markers in vital areas of uveal melanoma and retinoblastoma following treatment with radiotherapy and/or chemotherapy was not observed. CONCLUSION: Retinoblastomas and uveal melanomas, two tumours of differing pRB status, differ also in their immunohistochemical pattern for markers of the G1-S phase transition of the cell cycle. The results of the present study support the concept of (a) an autoregulatory loop between pRB and cyclin D1 in tumours with a functional pRB and the disruption of this loop in the presence of pRB mutation, as well as (b) a checkpoint mechanism in late G1, whose regulation via loss of p16 or pRB, or overexpression of cyclin D1 constitutes a common pathway to malignancy. Further, the results raise the possibility of cyclin D1 overexpression having a role in the pathogenesis of uveal melanoma.

Adolescent↗
PubMed1998

[Vitrectomy in diabetic retinopathy: outcome, risk factors, complications].

BACKGROUND: Functional results, risk factors and complications of vitrectomy for diabetic retinopathy were studied to improve our estimation for benefits and risks of vitreous surgery with current techniques. MATERIALS AND METHODS: The course of 389 consecutive eyes, who had undergone vitreous surgery for complications of diabetic retinopathy within a four year period, was retrospectively reviewed. The minimum follow-up was 6 months, the median 26 months. Risk factors were studied using multivariate logistic regression analysis. RESULTS: Six months postoperatively 25% of the eyes had a visual acuity of 20/60 or better, a vision of less than 5/200 was found in 25% of the eyes. The most important risk factors were detachment of the macula and iris rubeosis. Only 16% of the eyes with tractional detachment of the macula had a postoperative vision of 20/200 or better, although in 86% the macula was anatomically successfully reattached. Postoperative retinal detachment was observed in 18% of all eyes. The incidence of this serious complication was only 5% after surgery for vitreous hemorrhage, but 54% after vitrectomy for tractional detachment of the macula. CONCLUSIONS: In eyes with advanced stages of long-standing tractional detachment of the macula, the functional prognosis is very poor due to the underlying microvascular disease. In less advanced stages with vitreous hemorrhage and flat retina the risk of vitreous surgery is low.

Adult↗
PubMed1998

Choroidal hemangioma: MR findings and differentiation from uveal melanoma.

BACKGROUND AND PURPOSE: The aim of this study was to establish the MR imaging characteristics of choroidal hemangioma and to compare them with those of uveal melanoma. METHODS: Among 41 patients examined at 1.5 T (4-cm surface coil, T1-weighted and fast spin-echo T2-weighted sequences), 25 had uveal melanoma and 16 had circumscribed choroidal hemangioma. After i.v. bolus injection of gadopentetate dimeglumine, dynamic and T1-weighted sequences were acquired. RESULTS: In patients with choroidal hemangioma, uniform signal characteristics were detected on fast T2-weighted images. In 15 of 16 patients with choroidal hemangioma, lesions were isointense with vitreous on fast spin-echo T2-weighted images, whereas lesions in 24 of 25 patients with uveal melanoma were hypointense. Signal characteristics of uveal melanoma and hemangioma did not differ significantly on plain T1-weighted images. Enhancement was earlier and much stronger for circumscribed choroidal hemangioma than for uveal melanoma. After i.v. bolus application of gadopentetate dimeglumine, the increase of signal intensity was higher for circumscribed choroidal hemangioma (signal intensity ratio, 5.8) than for uveal melanoma (signal intensity ratio, 2.2). CONCLUSION: Circumscribed choroidal hemangioma may be difficult to differentiate from melanoma by ophthalmologic examination. Differentiation may not be possible if direct viewing of uveal space-occupying lesions is hampered by opaque vitreous media. The characteristic findings on fast spin-echo T2-weighted MR images and early enhanced images aid in differentiating choroidal hemangioma from uveal melanoma.

Adolescent↗
PubMed1997

MR anatomy and small lesions of the eye: improved delineation with a special surface coil.

To develop an improved investigation protocol for MRI studies of intraocular lesions, imaging with a small surface coil (diameter 6 cm) was compared with a standard surface coil (diameter 11 cm). Both coils were assessed initially on an eye phantom and then by studying 22 patients with uveal melanoma and similar lesions of the eye. The influence of bandwidth and field or view (FOV) were systematically studied and evaluated quantitatively. A smaller bandwidth improved image quality independent of surface coil size. The subsequent secondary increase in chemical shift artefact was acceptable. Smaller FOVs (60-80 mm) necessitated the use of a smaller surface coil. A smaller bandwidth also proved to be advantageous with the use of the smaller surface coil. In conclusion, a smaller-diameter surface coil improves MR imaging of ocular lesions. Pulse sequences with a small bandwidth maintain an acceptable signal-to-noise ratio when the FOV is reduced.

Artifacts↗
PubMed1997

[Long-term vision follow-up after vitrectomy in diabetic retinopathy].

BACKGROUND: We investigated whether visual acuity remained stable in the long run after vitrectomy for complications of diabetic retinopathy and which risk factors for a decrease in vision could be identified. MATERIALS AND METHODS: The charts of 389 patients who had undergone vitreous surgery for complications of diabetic retinopathy between 1990 and 1994 were retrospectively reviewed. The median follow-up was 26 months with a minimum of 6 months. RESULTS: Seventy-two percent of the eyes with a vision of 20/200 or better within 6 months after surgery retained this vision after 2 years. The percentage of eyes with vision of less than 5/200 was 25% after 6 months and increased to 41% after 4 years. After 2 years 24% of the eyes had lost two or more lines compared to the best vision within the first 6 months after surgery. The main cause for a decrease of vision in type-I diabetics was retinal detachment, in type-II diabetics a progression of maculopathy and opticopathy. Risk factors for a detachment were pre-existing retinal detachment before surgery and reduced postoperative vision. The risk factor for a progression of maculopathy and opticopathy was a silicone tamponade. CONCLUSIONS: Eyes with good vision soon after surgery remain stable in the long run. Eyes with advanced stages of diabetic retinopathy and only ambulatory vision after surgery have an increased risk for new loss of visual function in the long run.

Adult↗
PubMed1997

Long-term results after low dose ocular irradiation for choroidal haemangiomas.

AIM/BACKGROUND: The most common choice of treatment for choroidal haemangiomas (CH) in the past has been the employment of scatter photocoagulation of the surface. This management often requires repetitive treatment or additional invasive management due to massive exudative detachment of the retina. The aim of this retrospective study was to investigate the outcome of the alternative application of low dose external beam irradiation with high energetic photons on these tumours. METHODS: A total absorbed dose of 20 Gy was applied to a total of 51 symptomatic eyes: 36 with a circumscribed CH of the posterior pole and 15 with diffuse CH as part of the Sturge-Weber syndrome. The indication for treatment was an exudative retinal detachment including or threatening the fovea. The mean follow up times in each group were 4.5 and 5.3 years, respectively. Out of a group of 33 patients from whom reliable data could be derived, 17 had symptoms lasting longer than 6 months. RESULTS: In 23 cases (63.8%) with circumscribed CH complete resolution of the subretinal fluid was achieved; the remaining 13 cases (36.2%) showed residual serous detachment distant to the fovea. The visual acuity improved by two or more lines in 14 cases (38.9%), remained stable in 14 cases (38.9%), and decreased in eight cases (22.2%). The functional success was dependent on the lag duration between onset of first subjective symptoms and treatment. The morphological results with diffuse CH were similar to those of the group of circumscribed CH. The visual acuity (VA) at last examination was improved in seven cases (46.6%); in the remaining eight cases, VA was unchanged or had deteriorated. The poor functional outcome in the latter was mainly attributable to secondary glaucoma. CONCLUSION: External beam irradiation is a useful and a low invasive therapeutic option for CH. A successful functional outcome is dependent on the time delay between first onset of symptoms and the beginning of therapy, the formation of subretinal fibrosis, and also on secondary glaucoma in the case of Sturge-Weber syndrome.

Adolescent↗
PubMed1997

Uveal melanoma: detection of extraocular growth with MR imaging and US.

PURPOSE: To compare the sensitivity and specificity of magnetic resonance (MR) imaging with that of ultrasound (US) in the detection of extraocular extension of uveal melanoma. MATERIALS AND METHODS: In 70 patients, the diagnosis of melanoma and absence or presence of extraocular growth were confirmed with histologic examination (13 patients) or with ophthalmoscopy and surgery (57 patients). Unenhanced and enhanced T1-weighted and T2-weighted MR imaging was performed with surface coils at 1.5 T. A- and B-mode US scans were obtained with 8- and 10-MHz probes, respectively. RESULTS: Extraocular growth was confirmed in seven patients: Five patients had retrobulbar tumor, and two had optic nerve infiltration. US enabled detection in three cases, whereas six cases were diagnosed with MR imaging including both cases of optic nerve infiltration. False-positive findings were more frequent with US (n = 5) than with MR imaging (n = 1). CONCLUSION: MR imaging proved to be more sensitive and more specific than US in the detection of extraocular extension of uveal melanoma.

Eye Neoplasms↗
PubMed1997

MR of the eye with retrobulbar anesthesia.

MR imaging with retrobulbar anesthesia was performed in eight patients with uveal melanoma. Injection of 2 mL prilocain hydrochloride in 2% epinephrin into the eye muscle cone resulted in improved image quality in seven patients, without side effects. Ocular MR imaging can be indicated to clarify indeterminate sonographic findings in cases of extrascleral growth or to exclude optic nerve invasion in patients with tumors located at the posterior pole of the globe.

Anesthesia, Local↗
PubMed1996

Prognostic implications of monosomy 3 in uveal melanoma.

BACKGROUND: A high proportion of patients with uveal melanoma die of metastatic disease. In a subgroup of uveal melanomas there is the loss of one chromosome 3. To assess the prognostic implications of this genetic anomaly, we studied 54 patients for a median of 3.4 years. METHODS: 180 patients underwent primary enucleation for malignant uveal melanoma at the Ophthalmology Department of the Universitätsklinikum Essen between 1987 and 1993. Tumour material was available for chromosome analysis and DNA preparation from 69 of these patients (for logistic reasons unlikely, we believe, to introduce bias). 15 patients were excluded from our study: nine because the methods for assessment of monosomy 3 were unsuccessful; five because of insufficient information about their relapse status; one because histopathological data were incomplete. Of the 54 remaining patients, the tumours of 16 were assessed for copy number of chromosome 3 by karyotype analysis, of 30 by comparative genomic hybridisation, and of eight by both techniques. Clinical status was assessed by contact with family doctor or a clinical check up. Statistical analysis was by the log-rank test and Cox proportional-hazard regression. FINDINGS: The tumours of 30 patients had monosomy 3. 17 (57%) of these patients relapsed with metastatic disease, and the 3-year relapse-free survival rate was 50%. By contrast, of the 24 patients whose tumours had retained both chromosomes 3, none developed metastatic disease. In univariate analysis monosomy 3 was the most significant (p < 0.0001) predictor of poor prognosis in uveal melanoma, followed by tumour location (p < 0.0007) and tumour diameter (p < 0.0021). Histopathological subtype, age, sex, extrascleral growth, and tumour thickness had no additional predictive value. INTERPRETATION: In uveal melanoma, monosomy 3 is a significant predictor of both relapse-free and overall survival.

Aged↗
PubMed1996

Fast spin-echo MR imaging of the eye.

Magnetic resonance imaging of the eye usually includes T2-weighted images both for screening purposes and for characterization of melanoma. Conventional T2-weighted spin-echo (SE) imaging suffers both from long acquisition times and incomplete recovery of the vitreous' signal. A fast SE sequence was therefore compared prospectively with conventional sequences in 29 consecutive patients with lesions of the eye. Fast SE images delineated melanoma and other lesions of the eye from vitreous better than conventional T2-weighted images. Image quality and lesion conspicuity were improved on the fast sequence. Whereas melanoma appeared hypointense to vitreous on both types of images, subretinal effusion was hypointense on fast images and hyperintense on conventional T2-weighted images. Ghosting of the globe, which, however, did not decrease diagnostic value, was more pronounced on fast images. Conventional T2-weighted images may be replaced by fast SE images in MR studies of the eye with a gain in lesion conspicuity and significant time saving.

Eye Neoplasms↗
PubMed1996

Primary vitrectomy without scleral buckling for rhegmatogenous retinal detachment.

BACKGROUND: Pars planta vitrectomy has evolved as an alternative method in the treatment of more complicated rhegmatogenous retinal detachments. We report a series of patients who underwent primary vitrectomy with gas tamponade without the use of additional scleral buckling. METHODS: A retrospective study of 53 patients with a follow-up of 6-45 months (mean 17.8 months) was carried out. Preoperative findings included unusual, multiple or large breaks, vitreous haemorrhage, proliferative vitreoretinopathy and bullous retinal detachment. Preoperative visual acuity was between light perception and 1.0, with 30% (16/53) of patients with 0.4 or better. RESULTS: Retinal reattachment was achieved in 64% of cases (34/53) with one and in 92% (49/53) with one or more operations. Final visual acuity was between light perception and 1.0, with 41% (22/53) of patients with 0.4 or better. Cataract formation occurred in 86% (37/43) of all patients with a clear lens preoperatively. Macular pucker was noted in 11% (6/53) and postoperative proliferative vitreoretinopathy causing redetachment in 6% (3/53). CONCLUSION: With primary vitrectomy, a high final anatomical success rate with few intraoperative complications can be achieved in more complicated forms of rhegmatogenous retinal detachment. The major drawback of the procedure is the high incidence of post-operative cataract formation.

Adult↗
PubMed1996

[Limits and possibilities of vitreous body surgery in diabetic retinopathy].

BACKGROUND: Several indications for vitreous surgery for complications of diabetic retinopathy have been established, but there is little well-founded information concerning situations in which visual prognosis is poor and vitreous surgery should not be performed. MATERIALS AND METHODS: The charts of 389 patients who had undergone vitreous surgery for complications of diabetic retinopathy between 1990 and 1994 were retrospectively reviewed. The minimum follow-up was 6 months with a median of 26 months. Using multivariate logistic regression analysis we studied factors which were correlated with a postoperative visual acuity of less than 5/200. A model was developed predicting the probability of an unfavorable visual outcome in various situations. RESULTS: Forty-five eyes (12%) had a best postoperative visual acuity of less than 5/200. Risk factors were detachment of the macula, extent of the detachment, iris neovascularisations and the duration of visual loss. For reoperations similar risk factors were found. The chance that an eye with total tractional retinal detachment of more than 6 months duration and with rubeosis of the iris will achieve a postoperative visual acuity of 5/200 or better is only 2%. CONCLUSIONS: Eyes with total tractional retinal detachment, especially with longer duration of the detachment and rubeosis, have a very poor chance of achieving useful vision and should not be operated.

Adult↗