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Biomedical subjects

H Kraus

Publications and source records attributed to H Kraus.

At least 37 records · Page 2Linked to original sources
PubMed1998

Electrophysiological evaluation of visual loss in Müller cell sheen dystrophy.

AIMS: To describe the clinical picture and electrophysiological findings in Müller cell sheen dystrophy, a recently reported retinal dystrophy. METHOD: A basic ophthalmological evaluation as well as recording of standard electro-oculography and electroretinography were performed in one patient at the onset of visual loss and after 1 year of follow up. RESULTS: A 61 year old woman presented with visual loss in the right eye. Multiple folds at the level of the internal limiting membrane were seen at the posterior pole in both eyes. Macular oedema was present in the right eye. The visual acuity of the right eye was 6/30 and of the left 6/9. A paracentral scotoma was found in the right eye. Electro-oculographic examination of both eyes gave normal results. Electroretinography (ERG) revealed reduced b-wave and flicker amplitudes in the right eye; these potentials were normal for the left eye. The ON response in the right eye was reduced and delayed; it was normal in the left eye. A further loss of visual function was noted 1 year later in the right eye, but the ophthalmoscopic findings were unchanged. The ERG of the right eye had a negative waveform when dark adapted. Light adapted responses showed an unusual delayed b-wave, broad and delayed ON and OFF responses and a missing flicker response, suggesting a Müller cell dysfunction. Light adapted responses were slightly reduced in the left eye. CONCLUSIONS: Electrophysiological data indicate Müller cell dysfunction as a background of functional loss in Müller cell sheen dystrophy. This is in agreement with previously reported histological findings in this disorder.

Dark Adaptation↗
PubMed1997

[Electrophysiologic studies according to ISCEV (International Society for Clinical Electrophysiology of Vision) standards in children under 10 years of age].

PURPOSE: To analyze the value of electrophysiologic testing according to standards of the International Society for Clinical Electrophysiology of Vision (ISCEV) in infants less than 10 years of age. PATIENTS AND METHODS: In 64 infants less than 10 years, the results from of age electroretinograms (n = 47), visual evoked potentials (n = 30), or electro-oculograms (n = 1) were recorded. Twenty-nine infants were less than 6 years of age, and 17 infants were less than 3 years of age. Indications for examination were unexplained visual loss in 54 infants and familial hereditary retinal dystrophies in ten infants. Sedation with chloral hydrate was performed in seven children. RESULTS: In 40/64 infants (62%), the results of electrophysiologic examination were pathologic. In 29 infants visual loss was due to retinochoroidal dystrophies, and in 11 infants it was due to disturbances in the optic pathway. In 7/64, infants the suspected retinochoroidal dystrophy could be excluded. Therefore electrophysiologic testing was diagnostically accurate in 47/64 (73%) of cases. CONCLUSION: Electrophysiologic testing according to TSCEV standards can be reliably performed in infants less than 10 years of age. When the indication for electrophysiologic testing is made following meticulous ophthalmologic examination, diagnostic accuracy is given in at least 73% of cases.

Child↗
PubMed1996

[Blood supply to the liver in the human after 1 MAC desflurane in comparison with isoflurane and halothane].

OBJECTIVE: Objective of this investigation was to compare the effects of the new inhalation agent desflurane with equipotent doses of isoflurane and halothane on hepatic blood flow (tHBF). METHODS: 36 Patients scheduled for elective aortocoronary bypass grafting were enrolled to the study. tHBF was assessed by plasma clearance and hepatic extraction of indocyanine green, and standard haemodynamic parameters were measured by thermodilution technique. The measurements were performed awake and after intubation at equilibration of 1 MAC. All measurements were terminated before skin incision. RESULTS: We found a significant decrease of tHBF in all patients regardless of the inhalation agent used (H 918 ml/min +/- 107 to 625 ml/min +/- 181, I 930 ml/min +/- 195 to 637 ml/min +/- 137, D 940 ml/min +/- 129 to 677 ml/min +/- 122). The tHBF in relation to cardiac output also decreased significantly (H 17% +/- 5 to 14% +/- 3, I 16% +/- 3 to 14% +/- 5, D 20% +/- 5 to 18% +/- 6). No difference was seen between the groups according to tHBF and haemodynamics. CONCLUSION: The results of this study suggest that all inhalation agents included in the study significantly decreased tHBF during anaesthesia with the concentration of 1 MAC.

Aged↗
PubMed1996

[The retinal nerve fiber network layer in glaucoma. I. Introduction and methods].

In the retinal nerve fiber layer diffuse and localized defects can be seen in glaucoma. Photographs made with a green filter on black and white high contrast film allow to follow these alterations. This method will be used together with colour photographs for the statement of intra- and interobserver agreement.

Fluorescein Angiography↗
PubMed1996

[Surgical activity at the 2d Eye Clinic 1985-1994].

During 10 years the annual number of operations increased by 87%. The number of cataract surgery raised more than twice. A change of surgical techniques was seen: from intracapsular cryoextractions to extracapsular surgery with intraocular lens implantation and finally to phacoemulsification. The number of glaucoma operations increased markedly in accordance to the good results of early surgery. More than four times increased the number of pars plana vitrectomies. Further development of surgery is limited by space problems.

Czech Republic↗
PubMed1996

[Ambulatory cataract surgery].

The authors present an account of the experience with the first one hundred out patient cataract surgery which were performed at the Second ophthalmological Clinic in 1993 and 1994. They found that the only absolute contraindication is the need to administer general anaesthesia and they discuss the main problems which ensue from the present state of the health services and society as a whole.

Ambulatory Surgical Procedures↗
PubMed1995

[The value of aspiration cytology within the scope of triple diagnosis of palpable breast changes].

The diagnostic value of aspiration cytology and the overall diagnostic quality of the so-called triple test (aspiration cytology, mammography and physical examination) in the evaluation of palpable breast masses were investigated in a retrospective study. 608 histologically evaluated cancers and 224 benign lesions were investigated. A main purpose of the study was to find out whether the triple diagnostic test can replace surgical biopsy and thereby reduce the number of unnecessary biopsies. All lesions triple-diagnosed as malignant were histologically proved to be malignant, i.e. there were no false positive results. The rate of false negative results was found to be within the range reported for false negative results in fresh frozen sections. Based on these results we state that the dogmatic statement "every palpable mass in the breast must be excised" should be replaced by the recommendation "every palpable mass must be assessed and clarified". A great number of retrospectively unnecessary biopsies can be avoided by a systematic use of the triple diagnosis. The diagnostic safety of this method is close to that of open biopsy. In all cases where positive or negative concordant triplets are found, histological confirmation by biopsy can be avoided. Patients with benign lesions can be thoroughly followed up by repeated physical and radiological examinations. Patients with triple diagnostic malignant results can be adequately treated. Lesions for which triple diagnosis yields neither benign nor malignant, must be biopsied: This is also necessary in all cases with suspicious findings in mammography without a palpable mass, if the equipment for stereotactic or ultrasound- guided biopsies is not available.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy, Needle↗
PubMed1995

[Implantation of intraocular lenses in children].

The authors evaluated the visual acuity and binocular functions after implantation of an intraocular lens in 33 eyes in 29 children aged 5 to 15 years. Indication for operation was in 21 eyes traumatic, in 11 eyes congenital progressing and in one eye complicated cataract. There were 28 primary implantations, 6 secondary ones. The authors implanted 32 posterior chamber lenses and two anterior chamber ones. The mean age of the operated children is 12.9 years. The mean observation period is 1.7 years. A visual acuity of 0.5 or better was recorded in 81.8% eyes, incl. one third with a visus of 6/6. The most frequent cause of reduced visual is amblyopia. Stereopsis and fusion was found in 67.9% children. The most serious complication after operation was an enhanced inflammatory reaction, which was found in 36.4% eyes, decentering of the intraocular lens in 24.2% eyes. One intraocular lens (3%) was explanted because of complications. The most frequent postoperative complication was the development of secondary cataract in 81.8% eyes. Except for one eye it was resolved by Ng YAG laser capsulotomy.

Adolescent↗
PubMed1994

Optical triple sensor for measuring pH, oxygen and carbon dioxide.

A triple sensor unit consisting of opto-chemical sensors for measurement of pH, oxygen and carbon dioxide in bioreactors is presented. The pH and the CO2 sensor are based on the color change of a pH-sensitive dye immobilized on a polymeric support. The resulting changes in absorption are monitored through optical fibers. The oxygen sensor is based on the quenching of the fluorescence of a metal-organic dye. All three sensors are fully LED compatible. The sensitive membranes consist of plastic films and can be stored and replaced conveniently. The sensors are sterilizable with hydrogen peroxide and ethanol. In addition, the pH sensor is steam sterilizable. Accuracy, resolution and reproducibility fulfill the requirements for use in biotechnological applications. Calibration procedures for each sensor are presented. The working principle and the performance of all three sensors are described, with particular emphasis given to their application in bioreactors.

Carbon Dioxide↗
PubMed1994

[Does vascularization and the graft diameter affect the rejection reaction in corneal transplantation?].

The rejection (RR) is one of the most serious complications of perforating keratoplasty (PK). The authors evaluated in a retrospective investigation 316 PK made between 1986 and 1990 at the Second Ophthalmological Clinic in Prague. The authors investigated the number, onset, type of RR and its relation to the character of vascularization and size of the graft. The total number of RR was 66 (20.9%) with a mean onset period of 6.67 months. A significantly higher incidence (p < 0.01) of RR was found in the group of vascularized corneas (28.0%), as compared with corneas without vascularization (14.71%). The difference between groups with a superficial and deep vascularization was not significant. The authors did not find a significant difference in the incidence of RR in PK with a 7 mm diameter of the explant or smaller, as compared with explants larger than 7 mm.

Cornea↗
PubMed1994

[Silicone implants in untreatable glaucoma].

In the last years drainage shunts for otherwise untreatable glaucoma are effective. An own device is described, manufactured from medical, grade silicone. It consists of a tube with inner diameter of 0.4 mm and outer diameter of 0.9 mm. This tube is inserted in a disc, resembling a contact lens with a diameter of 12 mm, radius of 12 mm and a thickness of 0.55 mm. This part is fixed under a conjunctival flap between two recti muscles and the tube after proper shortening is introduced into the anterior chamber. The operation technique, results and complications in the first 11 eyes of 11 patients are reported. In 2 eyes it was not possible to lower the tension, in one only with additive medication. 2 eyes had a permanent hypotony. In 6 eyes a long term pressure normalisation was seen.

Adult↗
PubMed1993

[Implantation of bifocal intraocular lenses. Initial experience].

Twelve patients with bifocal intraocular lenses (3M, Suncoast and IOLAB) were evaluated. In 4 patients authors were not able to evaluate bifocality because of macular disorders and optic atrophy. In all remaining 8 patients the bifocality was strongly expressed. The main problem is a postoperative ammetropia. Implantation of bifocal lenses is connected with side effects which are not usually seen in implantations of monofocal intraocular lenses.

Adolescent↗
PubMed1992

General anaesthesia versus epidural anaesthesia for primary caesarean section--a comparative study.

Forty-seven healthy parturients undergoing elective Caesarean section were randomly allocated to either general anaesthesia (n = 24) or epidural anaesthesia (n = 23) under standardized anaesthetic and surgical conditions. Seven women of the epidural group required additional systemic analgesia or sedation following delivery of the neonate. Nine of 24 newborns obtained 1-min Apgar scores below 7 after general anaesthesia compared to only 3/23 after epidural anaesthesia. The time period to establish normal colour in the babies was 2.2 min after epidural and 4.9 min after general anaesthesia. Three of the 24 general-anaesthesia newborns demonstrated a tendency to hypotonia compared to only one in the epidural group. Twenty-four hours and 7 days after delivery all infants of both groups were completely normal. At the time of delivery maternal PO2 was higher in the general anaesthesia compared to the epidural group, due to higher inspired oxygen concentrations. Comparable results were obtained in umbilical PO2 venous values; lower pH values, however, were observed in the umbilical artery after general anaesthesia. There were no significant differences in the glucose levels between the groups. A significant correlation was established between uterine incision-delivery interval and 1-min neonatal Apgar scores in the general-anaesthesia group, but not in the epidural group. Our investigation did not show either the incision-delivery interval or the start of operation-delivery interval to play a role in neonatal outcome. Epidural anaesthesia is superior to general anaesthesia in Caesarean section under normal conditions with regard to neonatal outcome. Whether this is also true for critical conditions cannot be concluded from this study.

Adolescent↗
PubMed1992

[Keratoplasty in children].

The authors report anatomical and functional results of 24 keratoplasties in children aged 7 months to 15 years, incl. analysis of peroperative and postoperative complications. A total of 24 keratoplastics were performed on 20 eyes of 20 children. The mean follow up period was 2.1 years. Nineteen times the first operation was involved, three times the first, twice the second rekeratoplasty. The most frequent postoperative complication was an immunological reaction of the disk which occurred in 33%. It caused turbidity of five disks. After keratoplasty 11 disks remained transparent (45.8%), 10 disks became turbid (41.7%) and three disks semitransparent (12.5%). A visual acuity of 6/12 or better was recorded in 7 eyes (39%) and 6/60 and better in 6 eyes (30%). The cause of reduced visual acuity beneath 6/12 with a clear disk was in three instances amblyopia, in one case nystagmus.

Adolescent↗