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Biomedical subjects

H Witschel

Publications and source records attributed to H Witschel.

At least 19 recordsLinked to original sources
PubMed1995

Transscleral suture fixation of posterior-chamber lenses after cataract extraction associated with vitreous loss.

From 1987 to 1993, 21 patients who had undergone complicated cataract extraction that was associated with vitreous loss and transscleral suture fixation of the posterior-chamber lens (PC-IOL) in one eye (group A) and uncomplicated in-the-bag implantation of the PC-IOL in the fellow eye (group B) were followed prospectively. The follow-up period was 29.5 months (SD, +/- 17.0 months) in group A and 36.6 months (+/- 24.0 months) in group B. Visual acuity did not differ significantly between the two groups (P = 0.60, Wilcoxon test). In all, 17/21 patients in group A and 16/21 patients in group B achieved a visual acuity of > or = 20/40. Postoperative refractions measured in group A were +0.68 D more hyperopic than those measured in group B (P < 0.04). This result was consistent with the postoperative finding of a significantly deeper anterior chamber in group A (mean, 0.44 mm; P < 0.03). The accuracy of the desired postoperative refraction was poorer in group A. The risk for retinal detachment, cystoid macular edema, and intraocular pressure elevation was increased in patients who had had capsular defects and vitreous loss during cataract extraction. Nevertheless, transscleral suture fixation of PC-IOLs in patients with complicated cataract extractions associated with vitreous loss can give acceptable visual results. We recommend that +0.5 D be added to the calculated IOL power when severe complications require transscleral suture fixation of the PC-IOL during cataract extraction.

Aged↗
PubMed1993

[Isovolemic hemodilution in central retinal vein occlusion in patients less than 50 years of age].

AIM--Aim of the study was investigation of the effect of isovolemic hemodilution in patients younger than 50 years on the course of central retinal vein occlusion (CRVO) and to compare these results with those of older patients with CRVO. PATIENTS AND METHODS--We performed a prospective study on 35 patients younger than 50 years who were suffering from a central retinal vein occlusion. These patients were all treated by isovolemic hemodilution and compared to a group of older patients with CRVO with the same treatment. RESULTS--About 66% of the younger patients were men compared to only 46% in older patients. At least two cardiovascular risk factors were present in 8.5% of the younger and 54% of the older patients. 16 eyes showed the ischemic, 19 the nonischemic type of CRVO, a similar distribution as in older patients. The course of the disease was more favourable in younger patients, although ocular complications may occur in ischemic CRVO. Isovolemic hemodilution did not change the initial visual acuity of eyes with nonischemic CRVO, but led to an improvement in 56% of the eyes with ischemic CRVO. This means only a minor difference to the course of CRVO in hemodiluted older patients. CONCLUSION--In general, there is no principal difference between the CRVO in younger and older patients, but the course is more favourable in younger patients. On the basis of these findings we recommend isovolemic hemodilution in younger patients with ischemic CRVO.

Combined Modality Therapy↗
PubMed1991

Orbital squamous cell carcinoma after retinal detachment surgery.

We report on a 76-year-old patient with a squamous cell carcinoma of the left orbit. The tumour had no connection with the conjunctiva but was located at the site of an encircling band which had been inserted 13 years before. A major part of the tumour presented as a well circumscribed solid mass within the extraocular tissues next to the inferior equator, but the exenteration specimen also showed tumour extension within the adjacent choroid. Histological examination showed a well differentiated keratinising squamous cell carcinoma with numerous mitotic figures and many epithelial pearls. A thorough examination in search of a primary carcinoma of the lacrimal gland or the sinus, with invasion into the orbit, or an epithelial neoplasm elsewhere suggestive of metastatic disease into the choroid did not reveal any specific pathological findings. Thus the most probable origin of the tumour seems to be epithelium which had been misplaced during retinal detachment surgery and had subsequently undergone malignant transformation.

Aged↗
PubMed1991

[Chronic lipogranuloma of the eyelids after paranasal sinus operations].

Over a period of about 1 year we observed five patients who developed tumors of their eyelids a few days to 3 weeks after surgery on the paranasal sinuses through the nasal passage. One patient noticed a swelling of his ipsilateral eyelid during an irrigation procedure for the maxillary sinus, which was also followed by endonasal surgery. After surgery each patient developed an ipsilateral periorbital hematoma and subsequently solid indolent tumors of the eyelid without a tendency to regress over a period of 3 to 14 months. Therefore, surgical treatment was necessary. The histological examination showed lipogranulomas with giant cells and many lipid vacuoles of different size. Exploring the origin of these lipids, we performed a magnetic-resonance-spectrum analysis of one tumor sample. We predominantly found signals for linear hydrocarbons, which are the main components in paraffin-liquids. We presume that our patients developed lipogranulomas of their eyelids due to the paraffin introduced into the tissue by the ointment used to tampon the paranasal sinus after endonasal surgery.

Adult↗
PubMed1989

[Arteriovenous malformation of the orbit].

Arteriovenous malformation is a rare vascular disease of the orbit that has to be differentiated from arteriovenous fistulas (e.g., of the carotid sinus), arterial aneurysms, the varices and the angiomas. It develops in the presence of an underlying constitutional maldifferentiation of the vascular bed but usually only becomes manifest in early adulthood. Typical clinical signs are exophthalmos, often with pulsation and thrill; episcleral and conjunctival vascular congestion; secondary glaucoma; and, to varying degrees in the late stage, restricted movement with double images as well as functional losses. The therapeutic measures otherwise routinely applied for such vascular deformities - e.g., surgical excision or, even better, embolization - have to be handled with ease in the orbit, since these vascular convolutions are also supplied in all cases by the ophthalmic artery. Two typical cases are presented to illustrate the clinical picture, diagnosis, differential diagnosis, and treatment possibilities.

Adolescent↗
PubMed1989

Primary malignant melanoma of the orbit arising in a cellular blue naevus.

Primary malignant melanoma of the orbit is a rare clinical entity. We report the clinical course and present the light and electron microscopic findings in a case arising in a cellular blue naevus. While most orbital melanomas are associated with a naevus of Ota, there was no clinically visible abnormal pigmentation in our patient. The possible origin of the tumour cell and its ultrastructural features are discussed.

Adult↗
PubMed1989

[Histopathology of the eye--recent technics].

The histopathology of the eye is especially suitable for demonstrating the necessity and advantages of a close clinicopathological correlation. It should therefore be performed by a clinical ophthalmologist who is especially trained in histopathology. During recent years it has been realized more and more that metabolism and function in a living organism are only possible in relation to intact morphological structures. This led to a "renaissance" of morphology in general and of human histopathology and ophthalmopathology in particular. The workup of ophthalmopathologic specimens includes careful dissection of the globe, its macroscopic examination under the stereomicroscope, photographic documentation of interesting findings, and the application of all modern techniques of histopathology, such as light microscopy, electron microscopy, scanning electron microscopy, freeze-fracture techniques, and immunohistochemistry. The above methods are briefly discussed.

Eye↗
PubMed1988

[Retinal cryocoagulation in rubeosis iridis].

Patients with neovascularization of the iris were treated with cryocoagulation of the peripheral retina alone (Group A, n = 29), or in combination with cryocoagulation of the ciliary body (Group B, n = 19). The basic disease was either diabetic retinopathy or occlusion of the central retinal vein. After a follow-up of at least six months, a marked reduction in neovascularization of the iris was seen in most eyes. Intraocular pressure was reduced from a mean of 35.4 to 13.4 mm Hg in Group A, and from 55,2 to 6 mm Hg in Group B. A phthisis bulbi developed in six of 30 eyes (20%) in Group A and in 11 of 20 eyes (55%) in Group B.

Adolescent↗
PubMed1987

[Initial diagnosis of acquired immunologic deficiency syndrome (AIDS) by the ophthalmologist].

The authors report on two patients who presented with sudden loss of vision, due to irodocyclitis and retinochoroiditis in one patient and optic neuritis in the other. AIDS was diagnosed in both patients on the basis of a positive HIV antibody assay, lymphopenia, and a reduced helper-to-suppressor subset ratio. Soon afterwards, the patient with retinochoroiditis developed the full-blown picture of AIDS with cerebral involvement. Neither anticytomegaly treatment with DHPG nor triple therapy for toxoplasmosis was able to prevent the fatal course. The patient died within six months. In contrast, the patient with optic neuritis recovered full visual acuity. So far there has been no relapse, nor any opportunistic infection in other organs.

Acquired Immunodeficiency Syndrome↗
PubMed1987

[Pars plana lentectomy].

Pars plana lentectomy was performed in a total of 75 eyes of 63 patients. The main indications were congenital and infantile cataract, traumatic cataract, and complicated cataract associated with uveitis. The surgical technique, the difficulties encountered, and the intraoperative and postoperative complications are described. While there are hardly any problems associated with the operation and postoperative care in older patients, a number of difficulties occur in infants and small children. Of decisive importance here are, among other things, correct timing of the operation, a gentle surgical technique and disciplined optical rehabilitation, which requires close cooperation between the clinic and the parents. If these requirements are satisfied, the prognosis of congenital and infantile cataract can be considered favorable.

Adolescent↗
PubMed1986

[Malignant lymphoma of the eyelids].

A 51-year-old patient developed malignant lymphoma of both lower eyelids, which turned out to be immunocytoma of the lymphoplasmocytic subtype. The lymphatic tumor grew after several episodes of severe inflammation of the lids and conjunctiva in the presence of an underlying marked occupational allergy to chloramphenicol. The development of a so-called oculocutaneous immunocytoma from a reactive proliferation, its histological characteristics and its special clinical course are discussed on the basis of the present case.

Chloramphenicol↗
PubMed1984

[Neuroretinitis].

Eight patients presenting with the characteristic clinical picture of neuroretinitis are described. The decrease in visual acuity was caused by a papillitis, whereas the macular star developed later in the course of the disease when the visual acuity had already recovered. Five of our 8 cases were adults, a fact which demonstrates that neuroretinitis is not only confined to childhood. Three of the 8 cases were bilateral, two of them children. Two patients presented with neuroretinitis and additional inflammatory processes of other ocular segments (one with chorioretinitis and vasculitis; one with scleritis and uveitis), suggesting that a general vascular inflammation may be present in neuroretinitis. The macular star is produced by lipid-rich exudate in Henle's nerve fiber layer, thus giving the picture of stellate retinopathy. The exudate probably leaks from the disk due to a defect in the blood-tissue barrier or a loosening of the border tissue at the disk margin. The etiology of neuroretinitis remains an enigma. Serologic and cultural tests for preceding viral infections have so far been inconclusive.

Adolescent↗