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Biomedical subjects

M Reim

Publications and source records attributed to M Reim.

At least 109 records · Page 6Linked to original sources
PubMed1993

[Retinal hemodynamics in patients with arterial hypertension].

Arterial hypertension is a risk factor for the development of retinal, cerebral and renal microangiopathy. Therefore, a prospective study was started to investigate the progression of retinal microangiopathy in hypertensive patients. Initially, 254 patients were examined in a cross-sectional study. Following an ophthalmological examination, retinal hemodynamics were quantified by means of video-fluorescence angiography. Moreover, blood fluidity (hematocrit, plasma viscosity and erythrocyte aggregation) was analyzed. The severity of the retinal changes was defined according to the Neubauer classification. One hundred (40%) patients showed retinal changes corresponding to stage I; 133 (52%) were classified as stage II. Hypertensive retinopathy (stage III and IV) was encountered in 20 (8%) patients. Arm-retina time was significant prolonged among the hypertensive patients compared with a control group. Arteriovenous passage time showed no significant differences between hypertensive patients and reference values. Plasma viscosity was significantly increased in hypertensive patients and showed a significant increase with progression of the retinal changes. Hematocrit and erythrocyte aggregation were normal among the patients studied. The present findings show an alteration in blood fluidity among hypertensive patients, whereas retinal microcirculation showed no significant disturbances. Follow-up studies are planned to assess the development of retinal microcirculatory changes among hypertensive patients.

Adult↗
PubMed1992

The results of ischaemia in chemical injuries.

Severe burns of the anterior eye segment which include cornea, limbus and adjacent conjunctiva necrosis were accompanied by ischaemia. While necrotic conjunctival and subconjunctival tissue should be removed to eliminate its toxic influence, the opaque cornea and ischaemic sclera could not be removed. The ciliary body and the iris also suffer from ischaemic damage and under such conditions nutrient metabolites are deficient in the anterior segment of the eye. In the surrounding healthy tissues an inflammatory reaction begins after several days which induces an infiltration of the damaged tissues by leucocytes and an increase of N-acetylglucosaminidase and Cathepsin-D as demonstrated in model experiments and in patients. These destructive enzymes are apparently involved in the corneal and corneo-scleral ulceration and their activities may therefore be used to assess the severity of the ocular burn.

Acetylglucosaminidase↗
PubMed1992

[Juvenile optic neuropathy caused by Km variants of biotinidase].

A patient with a newly recognised variant of biotinidase deficiency presented with acute bilateral visual loss at the age of 10 years. A progressive optic neuropathy, a predominantly motor type neuropathy and spastic paraparesis developed over the following 5 years. Metabolic investigations revealed biotin depletion causing multiple biotin dependent carboxylase deficiency. The basic defect was a biotin recycling disorder due to a biotinidase Km variant with residual colorimetric activity of 4.4% of normal. Further investigations on plasma biotinidase showed biphasic kinetics with two different reduced Vmax values and two Km-values, one being almost normal and the other highly elevated. After a period of 2 months of oral substitution with biotin 10 mg per day the visual field defects improved as well as the distal spastic parapareses and motor neuropathy. We conclude that the differential diagnosis of unexplained bilateral optic neuropathy of juvenile onset, particularly when associated with upper and lower motor neuron disease should include biotinidase deficiency.

Adolescent↗
PubMed1992

[Value of corticosteroids in after-care of patients after cataract extraction and lens implantation].

In two double-blind controlled trials the anti-inflammatory effects of dexamethasone were examined in post-cataract extraction eyes after lens implantation in 321 patients. In the first trial, 103 patients were included. 49 eyes received eye-drops with 0.1% dexamethasone and antibiotics, the control-group of 54 eyes received the same antibiotics without any steroids. The follow-up was 2 months. In the case of unexpected complications, the patients dropped out. This was the case in 48% of the steroid-group and in 79% of the control-group. The main reason for this statistically significant difference were inflammatory complications in the control-group, which are difficult to quantify. The incidence of fibrinous reactions was not significantly different in the two groups, probably because of small numbers. In the second trial, we looked for fibrinous reactions. The follow-up was 3 weeks, 218 patients participated. They were divided into three groups: 71 patients received eyedrops with 0.1% dexamethasone 4x daily, 77 patients received the same drops 4x daily up to the fifth postoperative day, from then on 1x daily. 70 patients received the same drops 1x daily. A mild fibrinous reaction was seen in 10% of the high-dose-group, in 6% of the medium-dose-group and in 21% of the low-dose-group. Only the difference between the last two groups is statistically significant. We conclude that the therapy with corticosteroids after cataract extraction and lens implantation may be reduced early in the postoperative course.

Adult↗
PubMed1992

[Retinal circulation and current blood glucose value in diabetic retinopathy].

In 42 type II diabetic patients with nonproliferative diabetic retinopathy the arm-retina time (ART) and arteriovenous passage time (AVP) were measured by means of videofluorescein angiography. Glycosylated hemoglobin (HbAlc) as a parameter of longterm diabetic control and the blood glucose level were determined. The ART in the diabetics was similar to the ART of normals and the AVP was significantly prolonged. HbAlc level ranged between 5.6 and 12.2% (8.6 +/- 1.7%) and the blood glucose level between 4.5 and 22.9 mmol/l (11.4 +/- 4.5 mmol/l). Significant correlations were found between AVP and blood glucose (r = 0.37) and between AVP and HbAlc (r = 0.49). No correlation was found neither between ART and blood glucose nor between ART and HbAlc. A multiple stepwise regression analysis shows that of both investigated parameters HbAlc is the predicting variable for AVP. These results show that in diabetic patients the retinal blood flow is more influenced by the longterm diabetic control than by the blood glucose level at the time of examination.

Aged↗
PubMed1992

[Corneal sensibility following epikeratophakia].

The postoperative rate of reinnervation following corneal surgery is widely considered to be a useful indicator of the healing process. This study reports the corneal sensitivity of 14 patients following epikeratophakia for different indications (myopia, aphakia and keratoconus) after time periods ranging from 7 to 104 weeks. All transplants were clear at the time of measurement. A newly developed aesthesiometer (using a low electric current for stimulation) was employed. Nine positions on the operated eye were chosen for the measurements, five locations of the non-operated fellow eye served as controls. On the operated eye the corneal sensitivity peripheral to the trephination were significantly reduced at the 9 and 12 o'clock positions as compared to the other eye. The 3 and 6 o'clock locations showed no significant difference. On the epikeratophakia lenticule the sensitivity was significantly reduced at all points, the center showing the largest difference (p less than 0.001). No correlation with age, sex or the indication for the procedure was observed. Although there was a trend of a positive correlation between the postoperative time period and the central corneal sensitivity, the follow-up was too short to reach significant levels. The nearly complete lack of corneal sensitivity, particularly in the center of the transplant is therefore well compatible with its long-time survival, even when the lenticule has been prepared with the cryolathe and lyophilized for transportation.

Adult↗
PubMed1992

[Ocular findings in infection with Borrelia burgdorferi].

During the years 1988 to 1990 ten patients were observed in the eye clinic of RWTH Aachen with ocular findings of infection with Borrelia burgdorferi. 6 of them showed neuro-ophthalmological signs, 4 had uveitis. In both groups recent infections were documented in fresh and chronic stages of the disease, lasting longer than one year. The various clinical pictures of the disease following infection with Borrelia burgdorferi are described. As a vaccination against Borreliosis is not yet available, it is important to detect the antibodies against Borrelia burgdorferi early enough, to initiate an effective treatment.

Abducens Nerve↗
PubMed1992

[A family with blepharophimosis, ptosis, epicanthus inversus and telecanthus. Occurrence of the hereditary marker in five generations].

The condition with blepharophimosis, ptosis, epicanthus inversus and telecanthus is reported in one family over five generations. The syndrome is transmitted as an autosomal-dominant characteristic with a very high penetrance and expressivity, preferentially affecting and being transmitted by males. Affected females were infertile. There were no other accompanying systemic disorders. A three-year-old boy, who develops deprivation amblyopia, was first treated by levator attachment according to Friedenwald's method. Medical canthal surgery followed two years later to correct the epicanthus and telecanthus. A good clinical result was achieved by performing Mustardè's Z-plasty and shortening of the medial canthal ligament. Alternative techniques are reviewed briefly.

Blepharophimosis↗
PubMed1992

High-speed filming of the Periotest measurement.

Periodontal disease may be diagnosed with the Periotest technique, which involves electronically controlled and reproducible percussion of tooth. The movement on percussion was investigated with high-speed film and then compared with the return of teeth after static deflection for several seconds as has been reported previously by Lukas and Scholz. The elastic and viscous properties of the periodontium and the surrounding bony tooth socket are to a large extent non-linear. The 10-20 microns deflection of the healthy tooth represents only a fraction of static tooth mobility published by Parfitt or Schulte et al. The visco-elastic properties of a healthy tooth enabling the percussion of the Periotest tapping head to be decelerated in less than 1 ms are largely lost in periodontitis. It is this essential difference which the Periotest method utilizes.

Alveolar Bone Loss↗
PubMed1992

[Movement correction of digital sequence angiographies of the retina].

Retinal hemodynamics can be quantified from videoangiographic image sequences by digital image processing. Intensity changes of dye dilution curves provide dynamics parameters of the local retinal blood flow. The measuring points of dye dilution curves have to be fixed on identical image contents in each image of a complete image sequence. To obtain measurements for every pixel on the retinal surface a motion-compensated image sequence is required. A new method adapted to the compensation of eye motion and movement artifacts in Scanning Laser Ophthalmoscopy in long image sequences (300-500 images) is presented in this paper. To inhibit error propagation of time sequential motion estimation, the eye movement is divided into two dynamic movements components. The method presented permits compensation for eye motion in retinal fluorescein angiographic sequences. Owing to the short calculation times, this algorithm can be used in clinical routine.

Artifacts↗
PubMed1992

[Elasticity of capsulorhexis in the animal model].

A special caliper was designed to determine the stretching capacity of a circular capsulorhexis allowing measurements in 0.02 mm increments. A small capsulorhexis 4.5-6.0 mm in diameter could be stretched 2.7 times; a large capsulorhexis 6.5-8.0 mm in diameter was stretched 2.6 times the original diameter. A smooth circular capsulorhexis is very strong and stabile but also has significant stretching capacity. In a small capsulorhexis, there is the danger that zonular fiber defects or posterior capsular rupture may occur during manual expression, of the nucleus. A large capsulorhexis is more suitable for manual nucleus delivery.

Animals↗
PubMed1992

Chemical and thermal lesions in the orbital region.

In severe chemical and thermal burns the surroundings of the globe are frequently affected. Longstanding inflammatory reactions and severe scar formation around the globe are consequences from such damage. Lids, tarsi, conjunctival and subconjunctival tissues down to the fornices and the anterior orbit are destroyed. Beside medical therapy various operations are necessary to restore an environment for the globe to allow its survival.

Burns↗
PubMed1992

[Eye changes in acanthosis nigricans maligna--possible effect of growth factors in the etiopathogenesis of this paraneoplastic disease picture].

A 64-year-old white male presented to our hospital with hyperplastic tarsal and to a lesser degree bulbar conjunctivae. Approximately one month later the full clinical picture of acanthosis nigricans maligna developed. In addition to ectropia of the lower eyelids he showed madarosis; neither the linea grisea nor the lacrimal points were discerneable. On gastroscopy a diffusely growing gastric adenocarcinoma adjacent to the cardia was found and later confirmed histopathologically. The computertomography of the abdomen demonstrated one solitary metastasis to one parapancreatic lymphnode. It is generally assumed that in the course of paraneoplastic syndroms products secreted by the tumor induce changes in the target organs, e.g. the conjunctiva and the skin. In the presented case (1) southern blot analysis of the tumor tissue proved an increase of Epidermal Growth Factor-receptors, (2) immunohistochemistry showed prominent staining for Transforming Growth Factor-alpha. In conclusion, this case is suggestive of a possible link between growth factors and acanthosis nigricans maligna.

Acanthosis Nigricans↗
PubMed1992

[Keratoplasty with stored tissue. Initial results of a prospective study].

The first results of a prospective study on 50 patients who were followed up 2, 4, 6, and 12 months after keratoplasty are reported. The patients received a human cornea transplant, which had been cultured in a modified MEM medium for up to 28 days. We observed that the loss of epithelium during organ culture leads to delayed regeneration after keratoplasty. This is especially important for patients who have had this problem almost before transplantation. The slower increase of visual acuity after keratoplasty with organ-cultured material is due to increased folding of Descemet's membrane. Nevertheless the best vision was usually reached within 6 to 12 months. We saw seven immune reactions by which five transplants were lost. A comparatively low rejection rate was observed especially in the group of high-risk patients (27.2%). Organ culture may therefore have some additional positive effects for these patients.

Adult↗
PubMed1992

[2 years experiences with Tenon-plasty].

Tenon plasty proved useful in eye burns, especially in cases involving corneoscleral ulceration. This surgical procedure was carried out in 24 severely burned eyes of 21 patients. A total of 75 Tenon flaps were prepared, each of them covering one quadrant of the anterior eye segment. In 13 cases the burns were fresh, showing necrotic and ischemic areas in the sclera. In seven eyes an extended corneoscleral ulceration had developed and was covered with Tenon plasty. In four cases, when highly inflamed tissue was removed from the limbus the proximal conjunctiva retracted and exposed large areas of the sclera. Again, Tenon plasty was carried out. In all cases, the damage was so extensive that no conjunctiva was available to form flaps for plastic repair. Besides, the extensive ischemia would not allow free transplants. The duration of postoperative observation after Tenon plasty ranged from 6 to 42 months. In 14 of 24 eyes the denuded corneal stroma was covered with an artificial epithelium. In 11 cases keratoplasty was performed. The conjunctival epithelium regenerated in 10 eyes within 10 days, in another 10 eyes within 20 days, and in 4 eyes within 50 days. In all cases, the corneoscleral ulceration healed. Although some symblephara formed, and in a number of cases the cornea became more turbid and vascularized, Tenon plasty was very helpful in shortening the period of intensive inpatient treatment and provided a sound foundation for further reconstructive surgery.

Adult↗
PubMed1992

[The microvasculature and microcirculation of the peri-macular capillary network. New diagnostic possibilities with the scanning laser ophthalmoscope].

The scanning laser technique makes it possible for the first time to perform objective measurements of blood flow velocities in retinal capillaries. This new technique allows for continuous recording of retinal pictures at high resolution. Only the quality of the optical media of the eye limits the resolution of the retinal image. Sequences with a sample frequency of up to 50 images/s can be stored using a digital recorder. In these digital sequences the moving blood stream in retinal capillaries is visible. Segments of high and low fluorescence can be observed moving through the capillary network of the perifoveal capillaries. The flow velocities of these segments can be measured objectively using image analysis. In addition, morphologic information about the perifoveal capillary bed can be obtained by this new technique. Determination of flow velocities and morphological parameters give an objective means of assessing oxygen supply to the macular tissue. Furthermore, the degree of changes in the perifoveal microcirculation may provide objective data for estimating the prognosis of diabetic or senile maculopathy. Further investigation is needed to examine the relationship between changes in perifoveal microcirculation and the development of macular edema in various diseases.

Adult↗