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Biomedical subjects

E Scherfig

Publications and source records attributed to E Scherfig.

At least 19 recordsLinked to original sources
PubMed2000

The acoustic lighthouse effect. An ultrasonic response met in eyes after vitreoretinal surgery with silicone oil.

PURPOSE: To discuss and possibly explain the ultrasonic lighthouse effect, a metaphor suggested for an artifact-like phenomenon sometimes found by B-scan in eyes having had intra-ocular perfluorocarbon and/or silicone oil injected as part of vitreoretinal surgery. METHOD: Analysis of the ultrasonic findings with a view to the specific gravities of the above injected substances. Compared to water, perfluorocarbon has a higher and silicone oil a lower gravity; they are heavy and light, respectively. RESULTS: The elicited lighthouse effect may appear localized or 'mobile'. When evoked only from specific positions on the globe, most likely it is explained by a lens-like accumulation of material trapped at the vitreous base just under the transducer. When mobile it depends on head position; there is a gravitational shift in position of the material, as evident in particular when becoming visible in the anterior chamber. CONCLUSIONS: In case reports in literature slit-lamp verified anterior segment perfluorocarbon remnants have caused acoustic disturbances of a similar nature. In this study we found evidence that also silicone oil can underlie the acoustic lighthouse effect.

Adult↗
PubMed2000

The anterior lens capsule used as support material in RPE cell-transplantation.

PURPOSE: To investigate the use of an ocular basement membrane as support material for transplanted porcine RPE cells. METHODS: Porcine RPE cells were grown on bovine corneal extracellular matrix (ECM), isolated bovine- and porcine lens capsules, and tissue culture plastic. Cell density, and cell morphology were studied by phase contrast microscopy and transmission electron microscopy. RESULTS: RPE cells grown on porcine anterior lens capsule and on ECM obtained better morphology and higher final cell density than cells grown on plastic and on bovine anterior lens capsule. It was possible to transplant the porcine anterior lens capsule to the subretinal space in pigs. Within two weeks of observation, the lens capsule was well tolerated in the subretinal space. CONCLUSION: The anterior lens capsule seems to be promising as support material for use in RPE cell-transplantation.

Animals↗
PubMed1999

Resolution of retinal digital colour images.

Several digital colour cameras commercially available were fitted on a fundus camera. A test target placed in an artificial eye was used for measurements of the resolution of the resulting digital images and compared to film material. The maximal target resolution of the fundus camera was 6 microm corresponding to 24 microm at the image plane. The best film material matched this closely. To avoid aliasing, the size of the digital image must be 2-3000 pixels to match this resolution. This criterium is fulfilled by present high-end digital cameras. Further development of hardware and software is needed for their introduction into clinical settings.

Color↗
PubMed1999

Leiomyoma of the ciliary body. Report of 2 cases.

PURPOSE AND METHODS: The files of the Eye Pathology Institute contain only two cases of leiomyoma of the ciliary body. The diagnoses were re-evaluated, applying modern immunostainings. RESULTS: The tumors were composed of interlacing fascicles of spindle-shaped cells with bright eosinophilic cytoplasm and cigar-shaped nuclei. Both tumors were well-vascularized, mostly by thin, branching capillaries. Larger vessels were also seen. In one case the tumor perforated the sclera. The tumor cells reacted with the reticulum stain and the Masson trichrome and were positive for antibodies against: smooth muscle actin (SMA), muscle specific actin (MSA), laminin and vimentin (one case). CONCLUSION: Leiomyoma of the ciliary body is a rare smooth muscle cell tumor that may arise from either pericytes, ciliary - or intrascleral heterotopic muscle.

Actins↗
PubMed1999

Optic nerve oxygen tension in pigs and the effect of carbonic anhydrase inhibitors.

PURPOSE: To evaluate how the oxygen tension of the optic nerve (ONP(O)2) is affected by the administration of the carbonic anhydrase inhibitors dorzolamide and acetazolamide and by alterations in oxygen and carbon dioxide in the breathing mixture. METHODS: Polarographic oxygen electrodes were placed in the vitreous humor immediately over the optic disc in 20 anesthetized pigs. Blood gasses and cardiovascular physiology were monitored. ONP(O)2 was recorded continuously with breathing gasses of 21% O2-79% N2, 100% O2, 20% O2-80% N2, and 5.19% CO2-19.9%, O2-74.9% N2. Acetazolamide (15-1000 mg) and dorzolamide (6-1000 mg) were administered intravenously. RESULTS: The mean (+/- SD) ONP(O)2 was found to be 24.1+/-11.6 mm Hg when the pigs were breathing room air and 50.7+/-29.3 mm Hg when they were breathing 100% O2 (n = 15; P < 0.001). In response to breathing 5.19% CO2, ONP(O)2 changed from 20.8+/-5.6 mm Hg (with 20.0% O2) to 28.9+/-3.6 mm Hg (n = 4; P < 0.001). Intravenous injections of 500 mg dorzolamide increased ONP(O)2 from 16.4+/-6.1 mm Hg to 26.9+/-12.2 mm Hg, or 52.5%+/-21.2% (n = 5; P = 0.017). A dose-dependent effect on ONP(O)2 was seen with intravenous dorzolamide doses of 1000, 500, 250, 125, 63, 27, 15, and 6 mg. Intravenous injections of 500 mg acetazolamide increased ONP(O)2 from 23.6+/-9.5 mm Hg to 30.9+/-10.0 mm Hg (n = 6; P < 0.001), and a dose-dependent effect was seen with doses of 1000, 500, 250, 125, 31, and 15 mg. CONCLUSIONS: ONP(O)2 is significantly increased by the carbonic anhydrase inhibition of dorzolamide and acetazolamide, and the effect is dose dependent. These data demonstrate for the first time a direct effect of carbonic anhydrase inhibitors on ONP(O)2.

Acetazolamide↗
PubMed1998

[Cryotherapy of retinal prematurity in Denmark 1992-1996].

Retinopathy of prematurity (ROP) is a vasoproliferative disorder often met in infants of very preterm delivery. Lower stages usually regress spontaneously, but progression to so-called threshold-ROP should lead to anterior retinal ablation therapy, by cryopencil or laser. Fifty-three Danish infants born 1992-96 were evaluated in the University eye clinic of Rigshospitalet for the disease; 65 eyes of 36 infants had cryotherapy; eight infants developed severe bilateral visual handicap (22%). The reason for not giving cryotherapy to the remaining 17 was: too late referral in five, and ROP below threshold in 12; seven of the 17 later appeared in the (mandatory) national register for childhood visual handicap. Perusing these data the other way round, 15 of the registered 18 cases were thus known to us, while three had escaped referral. With reservation for the small numbers included, the national trend at present is an increasing annual number of subjects receiving retinal ablation therapy for ROP, and a decrease in severe visual impairment due to the disorder. Obviously all preterm infants at risk should be under early regular ophthalmic surveillance for ROP.

Child↗
PubMed1998

Human retinal pigment epithelial cell-induced apoptosis in activated T cells.

PURPOSE: The immune privilege of the eye has been thought to be dependent on physical barriers and absence of lymphatic vessels. However, the immune privilege may also involve active immunologic processes, as recent studies have indicated. The purpose of the present study was to investigate whether human retinal pigment epithelial (RPE) cells can induce apoptosis in activated T cells. METHODS: Fas ligand (FasL) expression was detected by flow cytometry and immunohistochemistry. Cultured RPE cells were cocultured with T-cell lines and peripheral blood lymphocytes for 6 hours to 2 days. Induction of apoptosis was detected by 7-amino-actinomycin D and annexin V staining. RESULTS: Retinal pigment epithelial cells expressed FasL and induced apoptosis in activated Fas+ T cells. Blocking of Fas-FasL interaction with antibody strongly inhibited RPE-mediated T-cell apoptosis. Retinal pigment epithelial cells induced apoptosis in several activated T-cell populations and T-cell lines, including T-cell antigen receptor (TCR)-CD3-negative T-cell lines. In contrast, RPE cells induced little or no apoptosis in resting peripheral T cells. Major histocompatibility complex (MHC) class II monoclonal antibodies, which block alloactivation, had no inhibitory effect on RPE-mediated T-cell apoptotic responses in MHC class II-specific CD4+ T-cell lines. CONCLUSIONS: Retinal pigment epithelial cells express FasL and induce TCR-independent apoptosis in activated human T cells through Fas-FasL interaction. Retinal pigment epithelial cells may constitute an immunologic functional barrier against potentially harmful T cells.

Apoptosis↗
PubMed1997

[Retinal detachment. The vitrectomy technique].

One hundred and ten eyes from 110 patients who in 1992 had undergone vitrectomy for regmatogenous retinal detachment were included in a retrospective study. Two year follow-up was obtained for 97 eyes. At the end of follow-up 45% of the eyes had complete anatomical success. Fifty-five percent had attachment of the macula. Anatomical success after a single operation was obtained in 33%. A visual acuity of more than 0.05 was obtained for 35% of the eyes at the end of follow-up. Eighty patients had a follow-up interview; of these 56% stated that the advantages of the operation outweighed the disadvantages.

Adolescent↗
PubMed1997

[Retinal detachment. The scleral buckling technique].

Eighty-four eyes from 83 patients who in 1992 had undergone scleral buckling surgery for rhegmatogenous retinal detachment were included in a retrospective study. Two year follow-up was obtained for 72 eyes. At the end of follow-up 93% of the eyes had complete anatomical success. A visual acuity of 0.5 or more was obtained for 45% of the eyes at the end of follow-up. Sixty-three patients stated that the advantages of the operation outweighed the disadvantages.

Adolescent↗
PubMed1997

Transvitreal retino-choroidal biopsy of suspected malignant lesions of the choroid. Follow-up of cases over 7 years.

The cases of transvitreal retino-choroidal (TVRC) biopsy from 1987 to 1994 were assembled in order to examine the efficiency, complications and risks to patients. Of 92 biopsies 91 had sufficient material for diagnosis. Eighty (87%) contained malignant tissue, whereas 10 cases were negative and two unsuccessful. Tumours of appropriate size were treated by brachytherapy. Twenty-three large tumours were enucleated primarily. Eight irradiated eyes had to be removed. In 31 cases, therefore, it was possible to examine the whole tumour for changes caused by the biopsy and to compare the typing of the biopsy with that of the whole tumour. In the irradiated eyes histologically viable tumour cells remained mostly in the inner part of the tumour. Scleral necrosis was not found. The technique used appears to be safe. Histological verification is highly recommended before any conservative therapy, inter alia to obtain true statistics of therapeutic results.

Adolescent↗
PubMed1995

Differential diagnosis of choroidal melanomas and nevi using scanning laser ophthalmoscopical indocyanine green angiography.

Fluorescein angiography is one of several standard ancillary diagnostic techniques in the evaluation of suspected malignant choroidal melanoma. Indocyanine green choroidal angiography has improved visibility of the choroidal circulation in comparison with fluorescein angiography. Studies concerning the use of indocyanine green angiography in the differentiation between nevi and melanomas have been few and the results inconclusive. A case of a choroidal melanoma (verified by histopathological examination) and a nevus in the same eye is documented by fluorescein and indocyanine green choroidal angiography performed by scanning laser ophthalmoscopy. This modality may be considered in the evaluation of a suspected malignant choroidal melanoma.

Aged↗
PubMed1994

Gas gangrene panophthalmitis. A case from Greenland.

A case of clostridium perfringens gas gangrene panophthalmitis developed after a penetrating eye injury. The affected eye became amaurotic, but the panophthalmitis was controlled by minimal surgical debridement and systemic antibiotic therapy with penicillin, fucidic acid and metronidazole. Elective enucleation was performed 15 days after the trauma for cosmetic reasons. The enucleated eye was examined histopathologically and showed massive retinal necrosis but no signs of bacteriae.

Anterior Chamber↗
PubMed1993

Eye surgery in severe retinopathy of prematurity. Experience from the Copenhagen University Eye Clinic of Rigshospitalet 1986-91, with emphasis on cryotherapy.

Data concerning observation of 40 pre-term infants referred to the Copenhagen University eye clinic 1986-91 for evaluation of ROP, predominantly of advanced stages, have been analysed. Twenty-one eyes in 13 subjects underwent cryotherapy at stage 3 (-4), on day 50-172 after delivery (median 72 days). Out of 19 eyes available for follow-up 10 obtained good of fair function; nine eyes ended with no L. Four subjects with ROP stage 4-5 at referral underwent vitrectomy and one trabeculectomy, all in eyes where surgery on beforehand was considered palliative or 'mainly experimental'. No indication for therapy was recorded in 22 infants; they mainly appeared for evaluation rather late in the course of ROP, to have the feasibility of reconstructive anatomy considered. The mean age of the infant at first discovery of ROP was 55 days when only stage 1-2 was found, 63 days when stage 3, and 69 days when at least stage 4 was described. Altogether, the range was 30-100 days. The inhomogeneity of the data is stressed. Though the possible benefit of earlier recognition cannot be proven, the investigation clearly indicates the need of uniform observation schedules nationwide and clearer indications for referral to the vitreo-retinal department.

Child, Preschool↗
PubMed1992

An unusual ophthalmic tumour in a 5-year-old boy.

A rare tumour in a 5-year-old boy is presented and discussed. In time and location the story had two parts (Fig. 1): 1) a conjunctival granuloma at the nasal limbus of the right eye was surgically removed. 2) a few months later a huge lesion presented in the posterior segment of the same eye. Was it an ocular tumour with extension to the orbit or an orbital process with impression or invasion of the eye? Repeated surgical biopsies have indicated nodular scleritis of the posterior eye segment as the definitive diagnosis.

Child, Preschool↗
PubMed1989

Transvitreal retinochoroidal biopsy.

Biopsies from retina and/or choroid were performed through a transvitreal approach in 14 patients during the 2-year period 1984-1986. A 20-gauge fine needle was used. The transvitreal approach was chosen because exact location of the biopsy could be documented by video recording and/or by photography. The needle was guided either by a stereotactic micromanipulator or by hand. Immediately after biopsy laser burns were placed around the biopsy hole. Light microscopical and, in selected cases, transmission electron microscopical examination of the material obtained showed malignant melanoma, choroidal haemorrhage, leukaemic infiltration of the choroid, intraretinal fibrosis in detached retina, atrophic retina after vasculitis and malignant lymphoma of the uvea. More than 2 years after biopsy, no retinal detachment due to the biopsy or any tumour-seeding has been observed. Two cases of vitreous haemorrhage cleared spontaneously. No visual impairment was related to the biopsies.

Adolescent↗
PubMed1988

Treatment of age-related macular degeneration by laser photocoagulation. Visual results 2-8 weeks and 2-4 years after initial laser treatment.

Laser treatment with blue-green argon, green argon and/or krypton red was performed on 578 eyes in 443 patients with neovascular age-related macular degeneration (AMD). The visual acuity was examined in all eyes 2 to 8 weeks after initial treatment and in 204 eyes in 167 patients 2 to 4 years after initial treatment. The short term results were as follow: 91/578 eyes (16%) had improved (greater than or equal to 2 lines on Snellen's charge or equivalent steps), 445/578 eyes (77%) remained unchanged and 42/578 eyes (7%) had deteriorated visual acuity (greater than or equal to 2 lines on Snellen's chart or equivalent steps). The reduction in visual acuity, may in about half of the 42 eyes be caused by too intensive laser application in the beginning of this study in 1983 and 1984 where treatment was applied with blue-green argon, which has now been abandoned. In the group with an observation time of 2 to 4 years, 42/204 eyes (21%) had improved, 119/204 eyes (58%) remained unchanged and 43/204 eyes (21%) had a deteriorated visual acuity. In the 204 eyes the subretinal neovascular lesion(s) were located extrafoveally in 52 eyes, juxtafoveally in 114 eyes and subfoveally in 38 eyes. It is to be pointed out, that even patients with a pre-laser visual acuity of 6/60 or worse obtained an improvement of visual acuity in 12/27 eyes. About 40% of the eyes needed re-treatment from 1 to 8 times. It is unknown whether the obtained results are to be considered marginal or more substantial.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1988

Isolated leukemic choroidal relapse in a child with acute lymphoblastic leukemia one year off therapy, diagnosed through transvitreal retino-choroidal biopsy.

A serous retinal detachment and choroidal hemorrhagic infiltration developed in a 17-year-old girl with acute lymphoblastic leukemia one year after cessation of therapy without concurrent bone marrow (BM) or central nervous system relapse. A choroidal biopsy through a sclerotomy with simultaneous release of subretinal fluid revealed no malignant cells. Accordingly, she was treated with prednisone, topical corticosteroid and atropine with normalisation of vision and clinical findings. Five months later the retinal detachment and choroidal infiltration recurred. In order to re-attach the retina once more and obtain a representative choroidal biopsy, a pars plana vitrectomy followed by a retinotomy with removal of subretinal tissue was done revealing leukemic infiltration of the choroid. Simultaneously a BM relapse was diagnosed.

Adolescent↗