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Biomedical subjects

A Berta

Publications and source records attributed to A Berta.

At least 19 recordsLinked to original sources
PubMed1999

The continuous-injection technique to reduce complications during retrobulbar anesthesia.

Retrobulbar as well as peribulbar anesthesia remain relatively risky procedures; retrobulbar hemorrhage and especially globe penetration or perforation can have blinding consequences. Our continuous-injection-technique greatly reduces these risks whether used for retrobulbar or peribulbar anesthesia. If the ophthalmologist starts injecting the agent while advancing the needle, the fluid pushes tissues away, possibly preventing a hemorrhage. Since resistance against the plunger is instantaneously experienced if the needle impacts the sclera, the ophthalmologist is adequately warned before actual perforation of the sclera occurs.

Anesthesia, Local↗
PubMed1998

Transforming growth factor-beta induced protein, betaIG-H3, is present in degraded form and altered localization in lattice corneal dystrophy type I.

Lattice corneal dystrophy type I (LCDI) is an inherited autosomal dominant local amyloidosis, restricted to the corneal stroma. Comparison of electrophoretic profiles of normal and dystrophic corneas revealed a 42 kD protein, which was present only in dystrophic corneas. The N-terminal sequence of this protein showed identity to transforming growth factor-beta induced gene product (betaIG-H3). A polyclonal antiserum was raised in chicken against a synthetic peptide identical to the N-terminal portion of betaIG-H3. On immunoblots, the antiserum stained the 42 kD band, and also a 68 kD band corresponding to the reported molecular weight of the intact betaIG-H3. In normal corneas, only the 68 kD band was present. Immunohistologically, the antiserum stained corneal subepithelial regions, including subepithelial deposits, in dystrophic corneas. In normal corneas, the staining was observed only in the epithelium. These results may reflect the role of betaIG-H3 in extracellular matrix construction and/or amyloid formation.

Amino Acid Sequence↗
PubMed1998

[Epidemiology of severe eye injuries. United States Eye Injury Registry (USEIR) and Hungarian Eye Injury Registry (HEIR)].

BACKGROUND: Both in industrialized and in developing nations, the devastating impact of ocular trauma on society is increasingly recognized. Lacking standardized surveillance systems, however, comparable epidemiological information has not been available previously. METHODS: For several years, the United States Eye Injury Registry (USEIR) and the Hungarian Eye Injury Registry (HEIR) have been collecting data on all types of serious ocular trauma, based on identical operating criteria and using standardized reporting forms. We performed a retrospective analysis comparing the two datasets, containing over 8,400 injuries from the U.S. and over 1,200 injuries from Hungary. RESULTS: Sixty percent of patients in the U.S. and 52% of patients in Hungary were less than 30 years of age, with an at least 80% male preponderance in both registries. The home was the most frequent place of injury in both countries (USEIR: 41%, HEIR: 35%); industrial premises represented no more than 14%. Guns were responsible for 12% of cases in the USEIR (HEIR, 1%). Champagne corks were identified as a unique and relatively common source of eye injury in Hungary (1.4%, as opposed to 0.07% in the U.S.). In the USEIR, 16% of injuries were caused by assault (HEIR, 24%; chi-square value = 36.7, p < 0.0000001). The enucleation rate was 12% in the U.S. and 1% in Hungary. CONCLUSIONS: The different findings in the two countries identify certain areas for the implementation of preventive measures (supplying champagne bottles with warning labels and a coordinated fight against violence in Hungary, stricter fireworks legislation in the U.S., public awareness for home injuries in both countries, etc.). Based on the encouraging results from this study, we plan to continue our efforts using modified reporting forms and an upgraded software. We invite additional countries to adopt the USEIR model.

Adolescent↗
PubMed1998

Comparison of different keratometers with the EyeSys videokeratoscope.

We compared the accuracy and the reproducibility of the measurements using a Haag-Streit, a Shin-Nippon, and a Carl Zeiss keratometer and an EyeSys videokeratoscope. Two investigators performed 20 measurements on 3 calibrated steel balls and 5 measurements on 22 normal corneas with all instruments. Calculating the accuracy of the measurements the limits of the 95% confidence intervals of the bias were determined. The accuracy was better than +/-0.1D for the keratometers, whereas it was better than +/-0.25D for the EyeSys videokeratoscope. The coefficient of reproducibility (1.96 x standard deviation) on test balls and corneas was smaller than 0.25D in the case of the Shin-Nippon and Carl Zeiss keratometers and the EyeSys videokeratoscope whereas it was between 0.25-0.5D in the case of the Haag-Streit keratometer. The Carl Zeiss keratometer was the best with respect to the accuracy and reproducibility of the measurements. Paired t-test was used to find possible significant differences between the results of the two investigators, but only clinically insignificant differences were found.

Adult↗
PubMed1997

[Corneal transplantation in Hungary. Data of the National Keratoplasty Registry 1992-1996].

Upon the request of the National Transplantation Committee a nationwide keratoplasty register is functioning at the Department of Ophtalmology, University Medical School of Debrecen. Since then at the end of each year we collected data from the University Departments and Hospitals performing corneal transplantation concerning their keratoplasties and related activities. According to the acquired data the number of corneal transplantations performed in Hungary was 299 in 1992, 298 in 1993, 320 in 1994, 426 in 1995, and 479 in 1996. Keratoplasties in Hungary were performed in 6 University Departments and in 13 Hospitals, all together in 19 institutions in the past five years. The overwhelming majority of corneal transplantations (in 1995 95.8% and in 1996 96.4%) were penetrating keratoplasties. The ratios of lamellar keratoplasties in 1995 and in 1996 were 3.0% and 2.5%, respectively. The ratios of sclerokeratoplasties were slightly above 1% in both years. The distributions of implanted fresh and preserved (eye bank) corneas were around 50-50% in these two years so, that in 1995 a somewhat more and in 1996 somewhat less preserved corneas were used. This ratio for preserved corneas was less than 20% in the period between 1992 and 1994. The law regulating the procurement and the transplantation of corneas is based on presumed consent and explicit objection which is the better type of regulation for the performance of keratoplasties in large numbers. The number of corneal transplantations in Hungary in the past years was close to the figures of industrial countries (England, Germany) calculated for similar populations, inspite of the fact that financing was in many respects unacceptable.

Corneal Transplantation↗
PubMed1997

Penetrating keratoplasty for pseudophakic bullous keratopathy.

Corneal decompensation after cataract surgery and intraocular lens (IOL) implantation has become the leading indication for penetrating keratoplasty during the past decade. We reviewed the clinical course and the surgical management of 212 patients with penetrating keratoplasty for pseudophakic bullous keratopathy treated at our Department during the last 15 years. Corneal transplantation for pseudophakic bullous keratopathy was successful in 76%. One third of the patients achieved a long-term visual acuity of 0.5 and more. At keratoplasty the original IOL was left in place in 129 eyes. We removed from and not replaced the IOL in 37 eyes and we performed IOL exchange in 46 eyes. The secondary IOL was an angle-supported flexible anterior chamber lens in 40 cases, and a suture fixated posterior chamber lens in 8 cases. During the penetrating keratoplasty for pseudophakic bullous keratopathy the most important question is how to manage the previously implanted intraocular lens. We have to decide whether the intraocular lens should be removed or replaced at the time of surgery. The choice of removing, retaining or replacing the intraocular lens at keratoplasty depends on the variable intraocular pathological conditions and each case requires individual evaluation.

Anterior Chamber↗
PubMed1997

Scleral reinforcement in progressive myopia and intraoperative ultrasound control of the cadaver fascia lata strip.

Scleral reinforcement (sustentaculum sclerae) is one of the operations against myopia. During the progression of myopia the eye grows. The chorioretinal layer can only moderately follow the expansion of the sclera, and mostly this is the cause of the complications that can cause permanent visual acuity decrease. The aim of the operation is to strengthen the posterior part of the sclera by implantation of a cadaver fascia lata strip, that slows down or stops the expansion of the eyeball, and this way prevents the development of complications. At our Department we perform the Snyder-Thompson technique. Between 1984 and 1994 343 operations were performed at our Department. We followed up the changes of the axial lengths by ultrasound (A-mode) examinations. The axial length decreased in 43.7% remained unchanged in 22.2% and increased in 34.1% of the cases. We controlled the location of the strip intra- and postoperatively with B-mode ultrasound. Nowadays scleral reinforcement is still the only possibility to stop or slow down the expansion of the eyeball in cases of progressive high myopia.

Cadaver↗
PubMed1997

Keratoprosthesis. Implantation of artificial corneas.

Keratoprosthesis (implantation of artificial, plastic cornea) is indicated in severe cases with corneal leucoma (non-transparent, cicatrized cornea) in which keratoplasty (corneal transplantation) is not possible or has repeatedly failed. In the past 40 years we implanted 37 artificial corneas (7 Cardona type, 29 Konstantinov type, 1 Fjodorov type). The visual acuity increase was temporary (lasting from a few weeks to a few months) in 25 patients. The visual acuity was at least 0.2 three years following the implantation of keratoprosthesis in 12 patients. One patient had 1.0 vision 10 years after surgery. Our results indicate that the implantation of artificial corneal is still an "ultimum refugium", an operation that can be justified only in monocular patients, in eyes that cannot be and/or had unsuccessfully been operated on with repeated keratoplasties. The visual improvement is temporary, but in some cases may last for several years. Still this is the only procedure by which useful vision can be provided, for shorter or longer time intervals, for patients suffering from corneal blindness (nontransparent cornea in otherwise functioning eye) whose only eye cannot be treated with corneal transplantation. Keratoprosthesis with better biocompatibility, better fixation techniques, and wider visual fields have to be developed before the implantation of artificial cornea can be looked upon as a surgical procedure with which full optical rehabilitation can be achieved.

Biocompatible Materials↗
PubMed1997

Results of contact beta-irradiation of choroidal melanomas.

Between the end of 1986 and the end of October 1996 81 patients suffering from choroidal melanoma were irradiated at the Department of Ophthalmology University Medical School of Debrecen. The irradiations were performed with Ruthenium-106 beta ray emitting scleral plaques (ophthalmic applicators). The radioactive plaques were implanted surgically, fixed by episcleral sutures onto the sclera covering the base of the tumour, and removed by another operation when sufficient time for irradiation had elapsed. For the treatment of tumours in the vicinity of the optic nerve special plaques were used with a notch for the nerve. Precise localisation of the tumours was established by intraoperative ultrasonography and transillumination. The mean follow up period was 3.5 years after the irradiation. Tumour regression was recorded by fluorescein angiography, ultrasonography and fundus photography. In 75 cases (92.5%) the treatment was successful. Additional laser photocoagulation was performed after irradiation in 26 cases. The irradiation by Ruthenium-106 scleral plaques of choroidal melanomas proved to be an effective treatment in cases of small and medium sized choroidal melanomas in our practice and the results are similar to those of the largest radiotherapy centers of Europe.

Beta Particles↗
PubMed1997

Changing techniques and indications for lamellar keratoplasty.

In recent decades, the number of lamellar keratoplasties (LKs) being performed worldwide has been gradually decreasing. However, new technical procedures have been developed and microsurgeons must consider modified indications for lamellar grafting. In the period 1946-1995, in the Department of Ophthalmology University Medical School of Debrecen, Hungary 3889 consecutive keratoplasties were performed of which 608 were LKs. In the period 1946-1960 special surgical material (biosutures) was used without operating microscopes and the leading indication for LK was corneal scar (leukomas). Between 1961 and 1979 with the development of microsurgical procedures (10/0 nylon sutures, operating microscope), the LK technique became more advanced. In the period 1979-1995 precision lamellar grafting could be performed with the widely available improved modern techniques. Changing indications for LK were noted in the second period and this tendency has subsequently continued. Currently the main indications for LK are "immediate" keratoplasty after chemical burns, and sclerokeratoplasty against recurrent pterygia. Their observations lead the authors to conclude that the possible reasons for the changing indications of LK are the new technical procedures, the increasing knowledge, the better immunological tests and the improved postoperative therapy.

Biocompatible Materials↗
PubMed1997

Excimer laser photorefractive keratectomy with different ablation zones.

In this study we would like to introduce the excimer laser, and to demonstrate our results and complications by using different ablation zones during photorefractive keratectomy (PRK) in the correction of myopia and astigmatismus. In 1996 we performed photorefractive keratectomy on 100 myopic eyes of 52 patients (28 females, 24 males). Mean age was 26.21 years (ranged from 19 to 54 years). The preoperative refraction ranged from -1.0 D to -18.0 Diopters. The diameter of the ablation zones were between 5 and 6.5 mm. We evaluated the results and the complications of the surgeries of 100 eyes which were performed with Schwind keratom F excimer laser. After 2 days, 1 week, 1 month, 3 months, and 6 months postoperatively we tested the best uncorrected and corrected visual acuities, and performed intraocular pressure measurement, slit lamp examination as well as corneal topography. The postoperative refractions were between +/- 0.5 to +/- 1.0 Diopters. After six months postoperatively the slit lamp examination showed that 80% of the patients had no corneal haze while 20% had stage I (Hanna) corneal haze. The smaller the diameter of the ablation zone was, the more pronounced the corneal haze and the night-glare were. The photorefractive excimer laser keratectomy is judged to be a safe method, although it might have some side-effects. The different ablation zones of this treatment means an important modification, that not only allows the method to meet the individual requirements, but reduces the chance of the complications as well. Based on the authors' experiences PRK for moderate myopia with large diameter ablation zones appears more predictable than than with smaller ablation zone diameters.

Adult↗
PubMed1997

Changing concept and modern techniques in cataract surgery.

Until the middle of the 80-ies the routine method of cataract surgery was intracapsular extraction (ICCE). Approximately 10 years ago the so called extracapsular cataract extraction (ECCE) started to become more and more widely used. After extracapsular cataract extraction had come into general use, it became possible to implant the IOL behind the iris, into the left in place capsular bag of the original lens. We usually perform extracapsular cataract extraction with posterior chamber lens (PCL) implantation as a routine procedure. In the last few years phacoemulsification started to gain acceptance. During this operation one breaks the nucleus of the lens into pieces with the help of ultrasound, and this way it is possible to remove both the nucleus and the cortex of the lens through a small wound. The first step in learning phacoemulsification is to be able to create a perfectly round hole on the anterior capsule (capsulorhexis). Besides using various manual techniques we introduced diathermal capsulotomy for capsulorhexis. This latter procedure is becoming more and more popular as it is safe, easy to perform, and gives excellent result.

Capsulorhexis↗
PubMed1997

In ophthalmology new possibilities for the use Nd:YAG laser.

Results of the technical development in laser technology created new possibilities in ophthalmic surgery, too. The easy access to various lasers offers an extraordinary opportunity for eye surgeons. At the Department of Ophthalmology of the University Medical School of Debrecen we performed 1400 laser treatments in 1996. Out of that 1100 were retinal Argon laser coagulations because of diabetic retinopathy, 200 YAG laser capsulotomies because of secondary cataract, and 30 laser iridotomies because of glaucoma. Additional 70 laser treatments were performed for special indications. During the laser treatment of the retina and the choroid we use Argon gas lasers, whereas the Nd:YAG laser used in the anterior segment of the eye is a solid-state laser. Our pulse mode modus synchronized Nd:YAG apparatus can produce megawatts of energy in nanoseconds. Authors give an account of the Nd:YAG lasers' possibilities in therapy (capsulotomy, iridotomy), present the most frequent indications of treatments in 1996, and compare it with international literature data. Authors demonstrate the newest principles of the Nd:YAG laser treatment of secondary membranes that are occasionally formed in the anterior chamber especially in the area of the pupil following cataract surgery.

Aluminum Silicates↗
PubMed1997

Different opening techniques in cataract surgery.

A retrospective study on the different opening techniques in cataract surgery at our Department in 1996 was carried out. In our everyday practice fornix based conjunctival flap and sclerocorneal oblique or vertical-oblique approach with a center at 12 o'clock was performed. In the case of hemorrhagic diathesis and secondary ACL implantation the corneal approach was preferred. After glaucomatous filtration surgery the incision was made temporally in some cases.

Cataract Extraction↗
PubMed1997

New indications for and technics in vitreoretinal surgery.

Vitreoretinal surgery has become a widely used ophthalmic surgical procedure since the late sixties. However, it remained an intensively developing field of surgical interventions, and indications still become wider and wider. The procedure starts with the removal of vitreous body, blood or inflammatory material from the vitreous cavity. After this, the given retinal disease, such as retinal detachment, macular hole, proliferative diabetic retinopathy, intraocular foreign body, etc. can be properly treated in situ. For that purpose a number of fine intraocular instruments, fluids, gases can be used. While the anatomical success rate can be up to 95%, the final visual outcome, due to the fact that the retina is not rarely seriously damaged, is less enthusiastic. However, a great number of previously untreatable vitreoretinal diseases can be managed in this way, nowadays.

Biocompatible Materials↗
PubMed1991

Tear plasminogen activators--indicators of epithelial cell destruction. The effect of scraping, n-heptanol debridement, and alkali burn of the cornea on the plasminogen activator activity of rabbit tears.

Plasminogen activator (uPA) activities were determined in the tears of rabbits following mechanical (scraping) or chemical (n-heptanol) debridement and alkali burn of the central part of the corneal epithelium. All three types of injury enhanced the plasminogen activator activities in the tears. The increase in uPA activity was highest in alkali burn, lowest for n-heptanol debridement. Scraping yielded an intermediate increase in uPA activity. The maximum value in activator activity was reached at 5 hours for mechanical injury and at 24 hours for chemical injuries. uPA activity values returned to the normal range by the time of re-epithelialization for mechanical scraping and 1-3 days following re-epithelialization for heptanol debridement and alkali burn. A trend was observed between uPA activity level and the size of the wound but the correlation was not pronounced (R = 0.538).

Alcohols↗