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R F Guthoff

Publications and source records attributed to R F Guthoff.

At least 19 recordsLinked to original sources
PubMed2006

Injectable self inflating hydrogel pellet expanders for the treatment of orbital volume deficiency in congenital microphthalmos: preliminary results with a new therapeutic approach.

BACKGROUND/AIM: Children with congenital microphthalmos are usually able to wear an eye prosthesis but the cosmetic aspect is determined by the size of the orbital volume deficiency. Instead of using a ball shaped standard hydrogel expander or a regular orbital implant, which would necessitate enucleation of the microphthalmic eye, this study investigates the feasibility of volume augmentation with injectable pellet expanders, as formerly suggested for acquired anophthalmos in adults only. METHOD: The pellet expander is made from a self inflating hydrogel that takes up water by osmosis (dry state: length 8 mm, diameter 2 mm, volume 0.025 ml; in vitro hydrated state after around 1 day: length 15 mm, diameter 4 mm, volume 0.24 ml; swelling capacity: 9.6-fold). This report concerns six patients (two girls and four boys) aged between 4 months and 42 months with unilateral microphthalmos who were treated by injection of 4-14 pellet expanders into the retrobulbar orbital tissue. Volume augmentation was 1-3.5 ml. The pellets were injected using a customised trocar and placed behind the microphthalmos directed into the intraconal space. RESULTS: The increasing orbital volume was noticeable within 2 days and was confirmed by ultrasonography and magnetic resonance imaging. The final result can be anticipated by the volume augmentation effect produced by the amount of saline solution injected in the orbital apex region. All patients were fitted with an artificial eye, which was subsequently enlarged every 3-5 months. Anophthalmic enophthalmos was fully compensated with this technique. No complications have been encountered to date. CONCLUSIONS: Orbital volume augmentation with injectable self inflating hydrogel expander pellets is apparently a safe, quick, and minimally invasive technique for various indications in orbital reconstructive surgery-for example, to treat an enophthalmic appearance in microphthalmos and congenital or acquired anophthalmos.

Child, Preschool↗
PubMed2006

[Three-dimensional confocal laser scanning microscopy of the corneal nerve structure].

PURPOSE: The aim of this study was the evaluation of a technology for in vivo visualization of distribution and morphology of corneal nerves by means of 3D confocal laser scanning microscopy (3D-CLSM). METHOD: The anterior corneas of four human volunteers were examined by an in-house developed confocal laser scanning microscope based on a commercially available instrument (Heidelberg Retina Tomograph II, Heidelberg Engineering GmbH, Germany). Raw stacks were converted using ImageJ (NIH, USA) for 3D-reconstruction using AMIRA 3.1 (TGS Inc, USA). RESULTS: The spatial arrangement of epithelium, nerves and keratocytes was visualized by in vivo 3D-CLSM. After 3D-reconstruction of volunteers' corneas, volume rendering and selective oblique sections have been done to demonstrate the nerves in the central human cornea. 3D-imaging shows thick nerve bundles rising out of the deeper stroma. The nerves further divide, resulting in fibers that are arranged parallel to Bowman's layer and are partly interconnected. Branches rising up to the superficial cell layer cannot be visualized. Wound healing following refractive surgery can be evaluated. CONCLUSIONS: 3D-CLSM allows in vivo visualization and analysis of the spatial arrangement of the epithelium, nerves and keratocytes of the human cornea. The developed method provides a basis for further studies on the alterations of the cellular arrangement and epithelial innervation in corneal diseases. This may help to clarify gross variations of nerve fiber patterns under various clinical and experimental conditions.

Adult↗
PubMed2005

[Epidemic keratoconjunctivitis. In vivo images of corneal structures with the confocal Rostocker laser scanning microscope (RLSM)].

PURPOSE: Epidemic keratoconjunctivitis (EKC) is a highly contagious infection caused by adenovirus types 8, 19, and 37. The formation of subepithelial nummular infiltrates may lead to permanent visual disturbance. These infiltrates consist histopathologically of an accumulation of lymphocytes, histiocytes, and fibroblasts. PATIENT AND METHOD: The reasons for the persistence of these nummular infiltrates are not fully understood. We examined a 28-year-old female patient with typical signs of EKC infection clinically and additionally with the RLSM. RESULTS: Nummuli were identified by the RLSM as areas with an accumulation of dendritic cells (supposed to be Langerhans cells) as well as so far unidentified punctiform structures located in the basal cell layer and in the region of the subepithelial nerve plexus. CONCLUSIONS: The RLSM allows us to investigate corneal microstructures in vivo with precise depth localization related to epidemic keratoconjunctivitis. Further investigations may disclose the role of dendritic cells in the pathogenesis of the nummular formation as well as their contribution to the variable persistence of partially threatening vision opacities.

Adult↗
PubMed2005

[Three-dimensional ultrasound biomicroscopic examinations for haptic differentiation of potentially accommodative intraocular lenses].

PURPOSE: The principal ability of potentially accommodative IOLs is based on an axial shift of the IOL optics induced by the ciliary body action in interaction with a reversible change in haptic angulation. The aim of this study was to investigate the accommodative performance of this new IOL generation. METHOD: The authors have designed a test device to study IOL performance experimentally. These results were extrapolated to the in vivo situation in patients with accommodative implants. RESULTS: The 3D high-resolution presentation of the anterior segment of the eye allows a separation of the IOL haptic elements. In vitro and in the selected in vivo cases a change in haptic angulation <10 degrees in combination with a maximal IOL shift of 0.5 mm was found. CONCLUSIONS: The simulation model used in combination with 3D ultrasound biomicroscopy provides information about the potential of accommodative IOL designs. Conclusions corresponding to changes in haptic angulation during accommodation can be drawn and applied to the in vivo situation.

Accommodation, Ocular↗
PubMed2005

[Listeria endophthalmitis].

Listeria monocytogenes is a rare cause of endogenous endophthalmitis. During the last 20 years about 30 cases have been published, all of which showed similar clinical features and a profound visual loss mainly owing to delayed diagnosis. This case report is about an otherwise healthy 41-year-old woman whose diagnosis was established 17 days after the onset of symptoms by microbiological cultures. Under sufficient therapy signs of local inflammation disappeared and intraocular pressure decreased. Pars plana vitrectomy was necessary; although post-surgery complications developed, the result was complete recovery of visual acuity.

Adult↗
PubMed2005

[Diseases of the lacrimal gland].

Experience with the differential diagnosis of lacrimal gland illnesses is limited in daily practice due to their rarity. It is therefore of particular importance to have guidelines for the practitioner by which he can decide on the application of conservative or surgical therapy, and whether it is necessary to take a biopsy to clarify the diagnosis. There is a wide spectrum of possible illnesses which include systemic diseases, inflammatory disorders, neoplastic, benign and malignant tumors. When a pleomorphic adenoma cannot be excluded, biopsy is contraindicated and complete tumor excision with its capsule is necessary to prevent the possibility of malignant transformation and a negative effect on long-term prognosis. In this overview, special interest is placed on the typical clinical aspects and imaging features of lesions of the lacrimal gland fossa, their differential diagnosis and management.

Adenoma, Pleomorphic↗
PubMed2005

Contribution to comprehension of image formation in confocal microscopy of cornea with Rostock cornea module.

AIM: To investigate the influence of refractive index of aqueous humour on imaging of corneal endothelium in confocal microscopy. To clarify the phenomenon of dark endothelial and bright epithelial cell membranes in confocal images of corneas. METHODS: Use of a novel digital confocal laser scanning microscope, a combination of the Heidelberg retina tomograph (HRT II) and the Rostock cornea module. Exchange of aqueous humour solution from domestic pigs against glycerol/water solutions (refractive indices eta = 1.337-1.47). Transelectron microscopy of endothelial and epithelial cell morphology. RESULTS: Under the terms of variable refractive indices no differences were observed for general imaging of endothelium. Bright cells were bordered by dark cell membranes in all experiments. Electron microscopy of endothelium and epithelium revealed differences in intracellular and cell membrane structure of both cell types. CONCLUSION: Source of specific confocal optical behaviour of endothelium does not come from interface conditions to aqueous humour, but may result from intracellular variations and ultrastructure of cell membranes.

Animals↗
PubMed2004

[The extracellular matrix structure in keratoconus].

PURPOSE: Keratoconus is a non-inflammatory disease characterized by progressive thinning of the central cornea. There are indications for an autosomal dominant heredity. Our purpose was to find correlations between gene expression and structural changes in extracellular matrix components. METHODS: Stromal RNA (keratoconus and comparison) was isolated from corneas, transformed to cRNA and analysed using biochips (Affymetrix). Structural investigations were performed by laser scanning and transmission electron microscopy. RESULTS: In keratoconus corneas there was an upregulation of different extracellular matrix components (collagen XV, metalloproteases) and a down-regulation of collagen IV (alpha1, alpha3) and versican. The morphological changes correlated to genetic obtained data. The orthogonal arrangement of the collagen fibrills (anteriorly and central) was altered in the collagen matrix of keratoconus corneas. CONCLUSIONS: The changes point on deregulation of the matrix arrangement. The interest in the cause of the disease is focused on the interfibrillar arrangement, the interaction between collagen and proteoglucanes.

Adult↗
PubMed2004

[Lateral orbital decompression for Graves' orbitopathy. Indication, surgical technique, and treatment success].

PURPOSE: In Graves' disease a discrepancy between volume increase of the orbital soft tissues and fixed volume of the orbital cavity leads to exophthalmos. The patients do not only feel cosmetically disfigured, they often complain about more or less painful retroorbital pressure sensation or show symptoms of compressive optic neuropathy or corneal exposure because of a significant lid lag. To solve this problem, different orbital decompression techniques have been developed. This is to report about our results with a modified Dollinger technique for lateral orbital decompression. PATIENTS AND METHODS: A total of 27 patients aged 19-76 years (mean: 45.1 years) with Grave's ophthalmopathy were recorded who had undergone orbital decompression by a lateral approach between June 1999 and April 2003. The modified Dollinger technique was performed by deepening the osteotomy to the level of the sphenoid wing and by additional resection of intraconal fat. RESULTS: The reduction of exophthalmos achieved after decompressive surgery averaged 2.9 +/- 1.1 mm. Of the patients whose indication for orbital decompression was a compressive neuropathy, the visual acuity improved postoperatively for 3 lines. Of the 16 patients with preoperative retrobulbar pressure sensation, 12 had no complaints after the operation. Remarkably no significant impairment of the ocular motility resulted after surgery. CONCLUSIONS: Decompression of the orbit by the modified Dollinger technique is a safe and effective approach to reduce exophthalmos, retrobulbar pressure sensation, and compression neuropathy as a result of diffusely elevated orbital tissue tension. In the case of direct compression of the optic nerve in the orbital apex, additional medial orbital wall decompression has to be considered.

Adult↗
PubMed2004

[Treatment of eyelid retraction in Grave's disease by recession of the levator complex].

BACKGROUND: The chronic stage in Grave's orbitopathy is characterised by fibrotic changes within the orbital soft tissues, especially the extraocular muscles. Retraction of the eyelids is a common clinical feature of this phenomenon. To solve this problem several techniques for lengthening the upper eyelid have been described with variable rates of success. In this report we describe our modified Harvey's technique for the correction of upper eyelid retraction which includes a complete recession of the Muller's muscle/levator complex from the tarsal plate without the interposition of a spacer. Finally only the skin and the superficial orbicularis muscle are sutured. We also report about our results with this procedure. METHODS: 8 patients (1 male, 7 female) with lid retraction in Grave's ophthalmopathy were recorded who had undergone the modified lengthening technique by an external approach between 2001 and 2004. Four patients underwent a bilateral procedure and 1 patient showed a significant under-correction, necessitating reoperation. So a total of 13 procedures were included in this follow-up study. Beside the common ophthalmological examination, special interest was put in the difference of the two eyelid apertures in primary position pre- and postoperatively. RESULTS: Within a follow-up period of at least 3 months we recorded an averaged lengthening of the upper eyelid of 3.1 mm. The difference of the two eyelid apertures in primary position improved from 2.2 mm preoperatively to 1.0 mm postoperatively. Only 1 patient needed reoperation because of a significant under-correction. There were no late over-corrections observed. CONCLUSIONS: The modified Harvey's technique to lengthen the upper eyelid is a safe and effective method to reduce upper eyelid retraction in Grave's disease. An eventually required orbital decompression or extraocular muscle surgery has to be done before the lid surgery.

Adult↗
PubMed2004

[Orbital manifestation of microscopic polyangiitis (mPA)--presentation of clinical cases].

BACKGROUND: Microscopic polyangiitis (mPA) is one of the ANCA-associated primary systemic vasculitides. It is defined as necrotic vasculitis without granuloma development and without minimal immuno-depots in situ. The clinical picture is characterised by destruction of the small vessels with the main manifestations in the upper and lower respiratory tract, in the lungs and kidneys. The eye manifestations were noted yet not so often. PATIENT: There were 2 clinical cases, aged 5-12 years, with primary eye manifestations of the mPA. The initial oedema and the reddening of the lid area were common to all the patients. The diagnostic excisions of the inflammatory tumour of the anterior orbital area have shown histologically vasculitis of the small vessels. mPA was diagnosed by clinical and immunological parameters, including the examination of the respiratory tract and kidneys. CONCLUSIONS: In inflammatory orbital pseudotumour, diagnostic excision and evaluation of the immunological parameters are useful for the exclusion of a systemic vasculitis. Proper examinations must be performed to determine other possible organ manifestations. Prognosis is characterised by the severity of kidney involvement. Early immunosuppressive therapy is crucially important for survival prognosis.

Child↗
PubMed2003

[Treatment of congenital clinical anophthalmos with high hydrophilic hydrogel expanders].

INTRODUCTION: Children presenting with congenital anophthalmos usually develop a smaller bony orbit, a constricted mucosal socket, and a shortened eyelid fissure. This causes problems when fitting these patients with a prosthesis. Clinical evaluation of the Wiese self-inflating hydrogel expanders has demonstrated their ability to expand the socket and eyelid fissure for inserting a more realistic prosthesis in shorter periods of time. PATIENTS AND METHOD: The study included 13 consecutive anophthalmic patients, eight unilateral and five bilateral. Each patient received a hemispherical osmotic tissue expander in the rudimentary mucosal socket and later a sphere implanted in the deeper soft orbital tissue. RESULTS: The use of hydrogel expanders enlarged the lid and palpebral fissure in all children, with good cosmetic results. It allowed insertion of custom-made glass prostheses with good cosmetic appearance very early in life. Growth of the bony orbit may be stimulated successfully by these expanders in the soft orbital tissue. CONCLUSIONS: The enlargement of constricted mucosal sockets and short palpebral fissures using self-inflating hydrogel expanders is a new and successful concept in treating congenital anophthalmos.

Anophthalmos↗
PubMed2003

[Congenital clinical anophthalmia and blind microphthalmia].

Congenital anophthalmia and blind microphthalmia are very rare conditions and there is no standard treatment available. Various previously reported therapeutical concepts are reviewed. The clinical picture can be divided into three subgroups with different therapeutical options recommended: in microphthalmia the conjunctival sac size is usually normal or slightly decreased. The use of non-expandable conformers is possible with good results. Patients treated with hydrogel expanders can wear a prosthesis earlier and with better cosmetic results. In congenital anophthalmia the conjunctival sac is very small and contracted and patients cannot wear a prosthesis or even a conformer. Hydrogel expander treatment--first for the conjunctival sac and second for the orbit--is the therapeutical option which may lead to good cosmetic results. Children >5 years of age and/or unsuccessful pre-treated cases may benefit from osteotomy to reduce mid-face asymmetry. To attain the main therapeutical goal in this subgroup, the ability to fit a normal prosthesis, a combination of different techniques like hydrogel expanders, dermis fat graft, lid surgery etc. may be necessary.

Anophthalmos↗
PubMed2000

The keratocyte network of human cornea: a three-dimensional study using confocal laser scanning fluorescence microscopy.

PURPOSE: Keratocytes of the living human cornea were examined to compare quantitatively spatial arrangement and cell volume of the stromal layers. This knowledge is required for further studies toward a quantitative understanding of cellular alterations in corneal pathology. METHODS: Three human corneas were stained with calcein AM and ethidium homodimer (Live/Dead Kit) directly after enucleation. The fluorescent cells were examined with confocal laser scanning fluorescence microscopy. High-resolution three-dimensional (3-D) volumes of < or =270 microm in the z-axis were reconstructed. Cell density and volume density were determined by computer-aided morphometry. RESULTS: Three keratocyte subpopulations were distinguished. Their spatial arrangement was visualized by 3-D reconstructions of the scanned volumes. Whereas cell density decreased progressively from the anterior (100%) to posterior (53.7%) stroma, volume density was highest in the posterior stroma (17.03 +/- 5.05%) and lowest in the central stroma (9.31 +/- 1.09%). In the anterior stroma, volume density was found to be 10.19 +/- 4.37%. CONCLUSION: Confocal laser scanning fluorescence microscopy allowed quantitative analysis and the visualization of the spatial arrangement of the keratocyte network in the living human corneal tissue for the first time. The results provide a basis for further studies of alterations of the normal cellular arrangements in corneal disease.

Cell Count↗
PubMed1999

[Transpupillary thermotherapy of choroidal melanoma].

PURPOSE: The purpose of this report is to evaluate the efficacy of transpupillary thermotherapy (TTT) to treat choroidal melanoma. PATIENTS AND METHOD: 17 patients with choroidal melanoma were treated, 6 patients with small tumors close to posterior pole received TTT only 11 patients were treated simultaneously with TTT and Ru 106 brachytherapy. To perform TTT a diode laser with a beam diameter of 1.5 to 3 millimeters was used. Exposure time ranged from 60 to 90 seconds until a light grey appearance of the retinal surface was reached. Follow-up examinations were performed at 1-month intervals. If the tumor was partially regressed additional TTT was performed to reach the endpoint of a chorioretinal scar. RESULTS: All tumors exhibited a reduction of tumor height in a mean follow-up period of 14.25 months. Side effects were minimal. CONCLUSIONS: Treatment with TTT may be useful as a complementary modality to brachytherapy. A longer follow-up time is necessary for final evaluation.

Adult↗
PubMed1998

[Trans-pupillary hyperthermia of malignant choroid melanoma. Initial experiences].

UNLABELLED: The purpose of this report is to evaluate the efficacy of transpupillary thermotherapy (TTT) to treat choroidal melanoma. PATIENTS AND METHODS: Twelve patients with choroidal melanoma were treated. Four with small tumors close to the posterior pole received TTT alone; 8 were treated simultaneously with TTT and Ru-106 brachytherapy. To perform TTT a diode laser with a beam diameter of 3 mm was used. Exposure time ranged from 60 to 90 s until the retinal surface became light gray. Follow-up examinations were performed at 1-month intervals. If the tumor was partially regressed, additional TTT was performed to reach the endpoint of a chorioretinal scar. RESULTS: All tumors exhibited a reduction of tumor height in a maximal follow-up period of 6 months. Four cases showed complete regression within 3 months. Side effects were minimal. CONCLUSIONS: Treatment with TTT may be useful as a complementary modality to brachytherapy. A longer follow-up time is necessary for final evaluation.

Adult↗