Biomedical subjects
U Thomann
Publications and source records attributed to U Thomann.
Successful phototherapeutic keratectomy for recurrent erosions in bullous keratopathy.
BACKGROUND: The treatment of patients with recurrent erosions due to bullous keratopathy is disappointing in cases when penetrating keratoplasty cannot be performed. A trial has been made to prevent recurrent erosions through the smoothing of the cornea with the excimer laser. METHODS: Excimer laser phototherapeutic keratectomy (PTK) was performed after removal of the epithelium. RESULTS: Sixteen patients (17 eyes) with recurrent erosions due to bullous keratopathy were treated. The mean follow-up period was 17.2 months (range: 3 to 32 months). All patients responded well to the treatment; their pain subsided after a few weeks. In four cases, a second treatment was necessary because areas with loose epithelium remained, which resulted in recurrent erosions. No complications have been seen so far. CONCLUSION: Excimer laser PTK is an effective, easy to perform treatment of bullous keratopathy.
Phototherapeutic keratectomy for bullous keratopathy.
AIMS: This study was designed to investigate the therapeutic potential of excimer laser for recurrent painful erosions in patients not suited to treatment with penetrating keratoplasty. METHODS: Phototherapeutic keratectomy (PTK) with the excimer laser was performed prospectively on a series of 13 eyes of 12 patients with recurrent corneal erosions in connection with bullous keratopathy of varied aetiology. The main complaint of the patients before the treatment was frequent attacks of pain. The patients selected either refused corneal grafting or could not for a variety of reasons expect to profit visually from an operation. The treatment was performed with the MEL 60 Aesculap Meditec excimer laser using either a spot mode (five cases), a scanning mode (three cases), or a combination of both (five cases). RESULTS: All patients responded well to the treatment, and the pain subsided after a couple of weeks. In five cases (38.5%) a second treatment was necessary because of persistent pain, which was, however, much less than before the initial treatment. In four of these five patients small corneal bullae persisted. The visual performance of the seven patients with visual acuity better than 20/200 ameliorated in two cases and remained unchanged in four cases. One patient lost two Snellen lines after the laser treatment for terminal glaucoma. The mean follow up was 14.1 months (range 1-28 months). No complications were seen so far. CONCLUSION: It was concluded that PTK is a very promising and effective outpatient treatment for patients with bullous keratopathy. This therapeutic approach is not thought to have been described before.
[Phototherapeutic keratectomy].
BACKGROUND: In the last few years the excimer laser has been increasingly used not only for refractive surgery but also for therapeutic purpose. We report about our two year experience with this form of therapy. PATIENTS AND METHODS: Phototherapeutic keratectomy (PTK) has been performed on 27 eyes of 25 patients. The following diseases have been treated: Recurrent erosions (14), 9 of them in connection with bullous keratopathy, persistent epithelial defects (4), corneal opacity (6), one of them due to macular dystrophy, limbal infiltrates (2) and pterygium (1). RESULTS: 3 of 4 patients with persistent epithelial defects and 92% of the recurrent erosions were treated successfully. Above all the treatment of recurrent erosions in connection with bullous keratopathy was very satisfactory. The patients with corneal opacity achieved a significant improvement of their visual acuity. CONCLUSION: The excimer laser is very suitable for therapy of different corneal surface pathologies. The possibility to treat painful bullous keratopathy is very encouraging.
[Pars plana vitrectomy and cerclage after successful glaucoma operation with Molteno implant].
A single or double plate Molteno Implant may control IOP in otherwise desperate cases. Fibrosis of the filtration bleb will lead to failure. We report about 4 patients (age 12 to 77 years--3 neovascular glaucoma, 1 with postinflammatory goniosynechia) who had good IOP after the implantation of a Molteno device. 10 to 26 weeks (mean 18.25) after glaucoma surgery we performed a pars plana vitrectomy because of different reasons: proliferative diabetic retinopathy, proliferative retinopathy due to central venous occlusion, ciliovitreal block mechanism, PVR D3. One aphakic eye was treated with silicone oil and an encircling band. 19 to 30 weeks after posterior segment surgery (mean 24.5) IOP remained controlled. We describe the technique of pars plana approach and putting an encircling band without destroying the preformed filtration bleb. Encircling techniques, pars plana vitrectomy and silicone oil in aphacic eyes seem to bee possible without loss of the filtration effect of the Molteno operation.
[The Molteno implant in intractable glaucoma].
The results of a study with Molteno-implants in eyes with intractable glaucoma, performed for the first time in Switzerland, are presented and discussed with regard to visual acuity, intraocular pressure, and painlessness.
[Cutaneous diphtheria imported from tropical countries].
Two cases of imported cutaneous diphtheria from tropical areas are described. Vacationing in the Seychelles, a 29-year-old man injured his left malleolus a few weeks before his return to Switzerland. The wound did not heal and an ulcer developed. Microbiologic investigation yielded toxinogenic Corynebacterium diphtheriae. There were no signs of systemic intoxication. The man had not been vaccinated against diphtheria since childhood. In the second case a 51-year-old woman returned from Thailand and Nepal with two very painful ulcers between the toes of her right foot, which was reddish-coloured. Microbiologic investigation again yielded toxinogenic Corynebacterium diphtheriae and there was no sign of systemic intoxication. Treatment with erythromycin brought about complete healing of the ulcers.
The human tRNAVal gene family: organization, nucleotide sequences and homologous transcription of three single-copy genes.
At least 13 independent tRNAVal gene loci were detected in the human genome. Three of these genes were isolated and shown to occur only once in the haploid genome. No further functional tRNA genes are located on the isolated clones. Two tRNAVal genes encode the known major and minor tRNAVal isoacceptors, the third may be a pseudogene because a corresponding tRNAVal is not yet known. Comparison of extragenic sequences did not reveal significant homologies, indicating the separation of these genes early in vertebrate evolution. An Alu-type repeat was found in two of the clones within several hundred bp distance from the tDNA. All three genes are transcriptionally active in a HeLa nuclear extract. We show here for the first time that homologous in vitro transcription of mammalian tRNA genes strongly depends on extragenic control regions: interestingly, as a consequence of different flanking regions, the transcription efficiencies vary by an order of magnitude among the genes for the major and the minor tRNAVal and thus reflect the concentrations of these tRNAs in vivo.
Age-dependent phenotypic expression of a pattern dystrophy of the retina.
We studied a family with pattern dystrophy of the retina (PDR) in order to elucidate the clinical course of the disorder, relations between the different forms, and the mode of inheritance. Thirty-nine family members, representing three generations, underwent a thorough ophthalmological examination, with fluorescein angiography whenever a macular abnormality was suspected. Of family members over the age of 32 years, 46.7% showed signs of PDR. We classified the clinical forms of PDR in this family into four types: minimal lesion, pseudovitelliform type, butterfly-spider type, and late-stage lesion. These forms were predominant in the order cited in age groups 31-40 years, 41-50, 51-60, and > 60 years. Significant visual loss occurred only after the age of 50 years, when 8 of 14 eyes had visual acuity of less than 20/25. Inheritance was autosomal dominant. PDR presented different clinical forms in members of this family, and in successive age classes patterns of increasing severity prevailed. Thus, the different phenotypic forms apparently represent transient stages related to the age of the patient.
Intraocular pressure after excimer laser photorefractive keratectomy for myopia.
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