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Biomedical subjects

A Wessing

Publications and source records attributed to A Wessing.

At least 73 records · Page 4Linked to original sources
PubMed1990

[X-chromosomal congenital retinoschisis. Clinical aspects and electrophysiology].

We evaluated retrospectively the clinical records and electrophysiological results of 52 patients suffering from X-linked congenital retinoschisis. Characteristic clinical findings were hyperopia (mean +2.3 +/- 3.1 D), reduced visual acuity (mean 0.24 +/- 0.2) and always macular pathology. Peripheral retinoschisis was present in 53% of the eyes. The natural course of the disease was normally stable. Complications were visual loss in 9.3%, vitreous hemorrhages in 4.7% and retinal detachments in 10.7% of the eyes. These complications generally occurred within the first decennium. Prophylactic laser coagulation was of no use because it was complicated by retinal detachment in 43% of our series. The electrooculogram was usually normal. In addition to the known electroretinographic findings of a low normal a-wave and reduced b-wave amplitudes, we found prolonged b-wave latencies and implicit times.

Adolescent↗
PubMed1989

Enucleation combined with orbital implants for malignant melanoma of the uvea.

Advanced malignant melanomas of the uvea unsuited for an eye salvaging approach require enucleation of the tumor containing eye. A series of 68 patients is reported who underwent enucleation combined with insertion of a spherical dura-encased implant after 30 Gray pre-irradiation therapy of the orbit. Postoperative results with special attention to cosmetic outcome and motility of the prosthesis suggest that the insertion of an orbital implant should be preferred to the enucleation with no implant.

Esthetics↗
PubMed1989

[Preoperative irradiation before enucleation in malignant melanoma of the uvea. Review of the literature and initial personal experiences].

The results of animal experiments and clinical studies concerning preoperative radiation of malignant extraocular tumors suggest that pre-enucleation radiation may be helpful in reducing the incidence of tumor-related death after enucleation of an eye containing a melanoma. Based on a retrospective study of 80 patients with malignant melanomas of the choroid or ciliary body, in which pre-enucleation irradiation with 8.5 Gray or 20 Gray was performed, no beneficial effect could be found in terms of better survival. The need for a prospective, randomized and possibly multicentered study is emphasized.

Adolescent↗
PubMed1989

[Long-term results of the treatment of Coats disease].

Fluorescein angiographies and clinical data of 265 patients (292 eyes) with primary retinal teleangiectasis were retrospectively evaluated. If patients showed the typical pathology of the fundus and were less than or equal to 20 years, they were summarized under the diagnosis Coats' disease (125 eyes). These patients revealed significantly more severe vascular changes and exudates compared with older patients with retinal teleangiectasis. The treated and untreated course was compared in the group of patients with Coats' disease. Coagulation treatment and in some cases additional retina detachment surgery resulted in a significantly better course of the disease in contrast to the untreated group. The degree of the pathology of the fundus was the main factor for successful therapy. If the vascular changes regressed, the situation was stabilized for the following years.

Adolescent↗
PubMed1989

[Dosimetry of ruthenium applicators with an eye phantom and small volume thermoluminescence detectors].

Even though 106Ru/106Rh applicators have been in clinical use over more than two decades for the radiotherapy of malignant uveal melanomas, the dosimetry of emitted beta radiation is still a physical problem. The dose rate at the applicator surface and the depth dose in tissue equivalent material can be determined only within +/- 30% error. Using new cubic-shaped thermoluminescence detectors (TLD) with small volume the dose distribution is examined in water equivalent material (RW-1). The spatial resolution is 14 times better compared to the previous technique. From dose measurements in an eye phantom the homogeneity of nuclide deposition and the depth dose distribution of a 106Ru/106Rh applicator are determined.

Brachytherapy↗
PubMed1988

[Coagulation therapy of senile macular degenerations. I. Avascular pigment epithelium detachments].

The fluorescein angiograms and visual acuity of 74 patients with avascular pigment epithelium detachment in age-related maculopathy were studied retrospectively. Thirty patients had received photocoagulation treatment, and 44 patients had been kept under observation without treatment. With regard to initial visual acuity, age, and follow-up time the two groups were statistically similar. After a mean follow-up time of four years no significant difference was found between the two groups as regards ultimate visual acuity (P = 0.9) or in the comparison between initial and ultimate visual acuity (P = 0.7). A deterioration in visual acuity was recorded in approximately two-thirds of the patients in both groups, while one-third showed improved or unchanged vision. Only in patients with an initial visual acuity better than 0.6 could this prognosis be significantly improved by coagulation therapy (p = 0.05). Higher age at onset and longer follow-up times are both unfavorable factors as regards the prognosis and cannot be influenced by photocoagulation treatment.

Aged↗
PubMed1988

[Coagulation therapy of senile macular degeneration. II. Extrafoveal choroid neovascularization].

A retrospective study was conducted covering a total of 229 patients with choroidal neovascularizations in age-related maculopathy. Of these patients, 81 had been treated by photocoagulation and 148 had been followed up without treatment. After four years' follow-up of statistically comparable groups the photocoagulation group showed significantly better results than the control group with regard to both final visual acuity (p = 0.01) as well as changes between initial and final visual acuity (p = 0.03). This therapeutic effect of photocoagulation treatment in extrafoveolar choroidal neovascularization was only observed in patients followed up for a maximum of six years (p = 007), while in patients who had been followed up for longer periods of time similar visual results between the coagulation and control groups were found (p = 0.4).

Aged↗
PubMed1988

Intracellular storage of sodium and magnesium in Drosophila Malpighian tubules. X-ray microanalysis of native cryosections.

Using electron probe X-ray microanalysis after cryofixation, cryosectioning and freeze-drying we investigated the content of electron-dark vacuoles in the intermediate cell region of the proximal segment of Malpighian tubules in Drosophila larvae. According to this method these vacuoles store sodium and magnesium in a high correlation (r = 0.98) of 5:1 ratio. Phosphorus, potassium and sulfur are also stored. In the intermediate groundplasm surrounding the vacuoles the element content is different from that in the vacuoles. The significance of vacuolar sodium and magnesium storage for the ionic metabolism is unknown. In addition to Na, Mg, P, K and S the vacuoles also contain 3-OH-kynurenine and other fluorochromes. With the pyroantimonate technique intravacuolar precipitates were demonstrated. X-ray microanalysis of the precipitates revealed sodium and calcium, although following cryofixation calcium was not detectable in the vacuoles by X-ray analysis.

Animals↗
PubMed1987

Bone-marrow transplantation and toxoplasmic retinochoroiditis.

A 33-year-old woman underwent bone-marrow transplantation following radiation and chemotherapy for chronic myelocytic leukemia (CML); immunosuppressive therapy was continued for graft-versus-host disease. Five months after successful transplantation, she developed necrotizing retinitis in both eyes with rapid progression over the following weeks. Due to her immunosuppressed state the patient developed pneumonia and died. Postmortem evaluation of the retinal lesions in both eyes disclosed infection by Toxoplasma gondii, which was also found in the brain and myocardium. Multiple viable toxoplasmic cysts were observed at the transition zone from a necrotic to a normal retina. Additionally, cysts of Toxoplasma gondii a normal retina. Additionally, cysts of Toxoplasma gondii were seen in the adjacent intact retina and in areas of necrosis with almost complete absence of retinal or choroidal inflammation. Toxoplasmosis should therefore be considered along with fungi and viruses in the differential diagnosis of necrotizing retinochoroiditis in immunocompromised patients.

Adrenal Cortex Hormones↗
PubMed1987

Giant cell astrocytoma of the retina. Clinicopathologic report of a case not associated with Bourneville's disease.

A 56-year-old man presented with a disc-based intraocular mass at the posterior pole with massive subretinal exudation. Fluorescein angiography, ultrasonography, and CAT scans did not aid final diagnosis. Four months later, the patient presented again, with massive tumor progression, total retinal detachment due to proliferative vitreoretinopathy, and rubeosis iridis. Pathologic evaluation of the enucleated globe revealed a giant cell astrocytoma of the retina.

Astrocytoma↗
PubMed1986

Complications of local beta radiation of uveal melanomas.

The results of local beta ray radiation of 295 eyes containing a uveal melanoma (including 74 melanomas of the anterior choroid and ciliary body) are presented with special respect to the complications of treatment. The most frequent complications were radiation retinopathy and optic neuropathy. Complications known to occur from other radiation methods, such as dry eye syndrome, loss of cilia, and scleral necrosis, did not occur in our series. The incidence of radiation cataract, as compared to the treatment with 60Co plaques, was lower in our series. An average of 700 Gy delivered to the scleral base of the tumor was needed for uveal melanomas which could be destroyed. This radiation dose resulted in a 10% incidence of radiation retinopathy.

Eye Diseases↗
PubMed1984

Solitary intraretinal macular hemorrhage.

Thirty patients presented with a solitary intraretinal macular hemorrhage (SIMH) without clinical evidence of associated retinal or choroidal vascular disease. The hemorrhages originated from the perifoveal capillary network and often extended into the central fovea. They were solitary in all cases, usually small and situated beneath the internal limiting membrane. Fluorescein angiograms showed no abnormalities except for blockage of normal fluorescence of retinal and choroidal vessels underlying the hemorrhage. Resolution of the hemorrhage mostly occurred within 1-2 months, with complete recovery of visual acuity. Possible pathogenetic mechanisms such as clotting disorders or Valsalva maneuvers could be found in only a few cases, while in the majority of cases SIMH seemed to be idiopathic.

Adolescent↗
PubMed1984

Healon in retinal detachment with proliferative vitreoretinopathy.

In 73 eyes, retinal detachments complicated by proliferative vitreoretinopathy (PVR) were treated by intravitreal injections of Healon, in addition to scleral buckling procedures. The number of completely reattached retinas three months postoperatively was dependent upon the grade of PVR: 50% were reattached when PVR comprised only one quadrant (Grade C-1); 30% when two to four quadrants were involved (Grade C-2, C-3 and D-1). Reattachment was not achieved in two cases of PVR with funnel-like configurations (D-2). Major complications that could be attributed to Healon did not occur. The results indicate that Healon injections, combined with scleral buckling procedures, are an encouraging approach to retinal detachments with PVR Grades C-2 through D-1.

Combined Modality Therapy↗
PubMed1984

[Initial results in percutaneous radiotherapy of malignant melanomas of the choroid with the linear accelerator].

Twenty-seven eyes harboring a choroidal melanoma which could not be treated by other methods were treated with external beam radiation using a linear accelerator. After a mean follow-up period of 15.6 months 3 eyes had to be enucleated. In two eyes fresh tumors developed, which were successfully treated with local beta-radiation. In the remaining 22 eyes the tumor growth was stopped or the tumor regressed. External beam therapy for choroidal melanomas seems to be an effective alternative to enucleation in eyes with tumors not accessible for other methods of treatment and which cannot be enucleated, e.g., single eyes.

Choroid↗