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Biomedical subjects

J Peregrin

Publications and source records attributed to J Peregrin.

At least 19 recordsLinked to original sources
PubMed2003

[Corneal surface analysis].

Fourier analysis is a powerful method of evaluating the surface of the cornea. In 50 patients after photorefractive keratectomy included in our study we measured spherical equivalent, regular astigmatism, irregular astigmatism and decentration retrospectively acquired by Fourier series analysis of corneal topography data 1, 3, 6 and 12 months after operation. Postoperative decentration increased significantly from a mean preoperative value. The preoperative and postoperative values are not significantly different. The Fourier spherical equivalent and the values of keratometric spherical (equivalent) are highly correlated. Correlation among decentration, irregular astigmatism and best corrected visual acuity is important for clinical practice. Due to Fourier analysis we obtain information, which could explain worse results of some surgeries.

Astigmatism↗
PubMed2003

[Vascular complications after pancreatic transplantation].

Transplantation of pancreas is presently the only way of treating diabetes of the 1st type, capable to secure a long-term normoglycemia. In spite of the fact that the surgical technique and tactics of the whole intervention has been standardized over the last years, surgical complications and more specifically vascular complications still pose a certain risk of the graft loss. The thrombosis of vessels of the transplanted pancreas occurred in our group in 4.1 per cent of cases. The other rare complications included a false aneurysm of the supplying artery and stenosis of the out-coming vein from the pancreatic graft. Both these complications were successfully treated by a radio-invasive approach. A refinement of the surgical technique and the introduction of new immunosuppressive drugs manifests favorably in decreasing occurrence of vascular complications after the transplantation of pancreas.

Adult↗
PubMed2002

[The photopic ERG response in diabetes mellitus].

The authors made photopic ERG examinations according to the international standard in 82 diabetic patients. They recorded a significant reduction of amplitudes of the b wave in a group of 38 patients who at the time of the examination did not have yet any pathological changes on the fundus. Regressive analysis did not prove after laser photocoagulation in these patients, contrary to a control group and diabetic patients with simple diabetic retinopathy, any correlation between the patients age and the extent of the retinal response. Photopic electroretinograms must be included in the electrophysiological diagnostic arsenal in diabetes.

Adaptation, Ocular↗
PubMed2002

[Optic disc pits and maculopathy (electroretinography study)].

An ERG examination according to the international standard was made in 55 patients with pits in the optic nerve disc. 19 of them suffered from concurrent maculopathy. Electroretinography revealed in scotopic responses a significant reduction of amplitudes of oscillatory potentials and reduction of potentials of the b wave in standard (maximal) reactions. Even more markedly the cone reactions and flicker were reduced--responses to intermittent (30 Hz) photostimulation. The authors consider maculopathies with pits a separate nosological unit with possible hereditary transmission. ERG signalizes a more extensive alteration of retinal structures than affection of the centre, probably on the basis of the circulation. Maculopathies with pits are also characterized by the fact that the dramatic drop of amplitudes is associated with the patient's age or the duration of the disease.

Adolescent↗
PubMed2002

[Effect of YAG capsulotomy of secondary cataracts on visual functions].

1. 20 patients (20 eyes) with secondary cataract and best corrected visual acuity (BCVA) of 20/30 or 20/20 using Snellen charts were examined before Nd-YAG capsulotomy and 14 days postoperatively. 2. Contrast sensitivity (CS) was tested on a computerized system of the Contrast sensitivity 8010 type and on VCTS charts in 6 spatial frequencies, BCVA was measured on the logMAR charts with Landolt rings and influence of glare of 342.6 cd/m2 was tested using Brightness Acuity Tester (BAT). 3. BCVA (without and under glare) in patients before and after YAG capsulotomy was significantly lower compared to the control group (p < 0.001). Postoperative improvement of BCVA was markedly higher on logMAR charts (up to 6.6 standardized lines) than using Snellen charts (1 line). 4. CS (without and under glare) using both methods in patients before and after YAG capsulotomy was significantly lower compared to the control group (p < 0.05 to p < 0.001) in spite of significant improvement postoperatively (p < 0.05 to p < 0.001), first of all at intermediate and high spatial frequencies. 5. Glare had only nonsignificant influence on BCVA and CS in all groups.

Aged↗
PubMed2001

[Visual function in myopia 2 years after photorefractive keratectomy].

1. 86 myopes undergoing photorefractive keratectomy (PRK) with refraction from -0.25 D to -12.00 D were divided into 4 groups: A: up to -2.75 D, B: -3.00 D to -5.75 D, C: -6.00 D to -8.75 D and D: -9.00 D to -12.00 D. 20 emmetropes of the same median age were evaluated as a control group. The patients were examined 2 years after PRK. 2. Best corrected visual acuity (BCVA) increased in groups A, C, D and decreased in group B compared to values one year after PRK. Both changes were only nonsignificant. 3. Contrast sensitivity (CS) was equal to values one year after PRK in group A, the same was true for groups C and D with exception of lower values in the highest spatial frequency. In group B, CS decreased significantly compared to values one year after PRK. 4. In groups A, B a C number of patients without rest correction increased, regression was seen only in group B. 5. BCVA changed only nonsignificantly under glare of 41.1 cd/m2, 342.6 cd/m2 and 1360.4 cd/m2 in 97% of patients.

Adolescent↗
PubMed2001

[The scotopic electroretinogram and age].

1. Electroretinographic examination according to recommendations of the International Society for Clinical Electrophysiology of Vision (ISCEV) was implemented in 115 healthy subjects of different age groups. 2. No significant difference was recorded in the results of men and women. 3. The amplitudes of all investigated retinal responses decline in a linear fashion with age and their peak latencies are prolonged. The mentioned changes are statistically significant even if changes of 0.5 to 0.8% per year are involved.

Adaptation, Ocular↗
PubMed2001

[Comparison of visual function in myopia over -6.0 dpt after photorefractive keratectomy and laser in situ keratomileusis].

1. 41 myopes undergoing PRK and 31 patients undergoing LASIK for correction of spherical refractive error were examined before and 1, 3, 6 a 12 months after surgery on Schwind Multiscan with ablation zone between 5 and 7 mm. Mean preoperative spherical equivalent of refraction was -8.0 +/- 1.7 D in PRK group and -9.2 +/- 2.1 D in LASIK one. 2. Contrast sensitivity (CS) was tested on a computerized system of the Contrast sensitivity 8010 type in 6 spatial frequencies (0.74; 1.97; 3.69; 7.39; 14.77; 29.55 c/deg) and the best corrected visual acuity (BCVA) was measured on the normalized charts with Landolt rings. 3. At 12 months postoperatively, mean spherical equivalent of refraction was -0.6 +/- 1.0 D (PRK) and -1.0 +/- 0.8 D (LASIK). A refractive error within +/- 0.5 D had 31.5% (PRK) and 57.5% (LASIK) patients. Increasing of BCVA was measured in 51.5% (PRK) and 41.9% (LASIK) patients about 1 optotype to 2.5 lines. Mean CS in 6 frequencies reached 99.4; 102; 105; 109; 115 and 140% of preoperative values in PRK group and only 96; 95.8; 96.3; 95.8; 97.8 and 94.6% in LASIK one. 4. At 12 months after surgery, mean spherical equivalent, CS was better and number of patients with increased BCVA was significantly higher after PRK, than those attained with LASIK. On the other hand, a number of patients with a refractive error within +/- 0.5 D was higher and percentage of reoperations was lower in LASIK group.

Adolescent↗
PubMed2000

[Analysis of the time course in electroretinography potentials].

1. For isolating of electroretinographic oscillatory potentials (Ops) a method of algebraic polynomial approximation of the low-frequency course of the electroretinogram is described. 2. Using the described method of approximation in 16 subjects, the isolated Ops displayed peak-latencies by 1-2 ms shorter than using the Fast Fourier Transform and a time window. Moreover, the amplitudes of OP1 were by 20% and of OP2 by 6% higher.

Electroretinography↗
PubMed1999

[Electrophysiology in hypovitaminosis A].

Electroretinographic examinations performed according to the international standard were used in two patients with alimentary hypovitaminosis A. In one instance a mentally caused long-term deficiency of dietary vitamin A intake was involved, in the second instance a fistula from the proximal jejunum into the transverse colon. In both instances night blindness was reported. The initial vitamin A values were 1.0 and 0.6 micromol/l resp. and after substitution therapy they rose to 2 micromol/l. While the rod and maximal ERG responses improved gradually, the oscillation potentials remained pathological as regards amplitudes and latencies. We consider them therefore a sensitive indicator of the electric sensitivity of the retina also in other cases of confirmed or suspected vitamin A deficiency. The existence and orientation of our metabolic and gerontological clinic provides adequate opportunities for these investigations.

Electroretinography↗
PubMed1999

[Changes in visual function in myopia 12 months after photorefractive keratectomy].

1. 110 myopes undergoing photorefractive keratectomy (PRK) with refraction from -0.25 D to -12.0 D were divided into 4 groups: A: upto -2.75 D, B: -3.0 D to -5.75 D, C: -6.0 D to -8.75 D and D: -9.0 D to -12.0 D. BCVA using the computerized method with Landolt rings and CS using an adjustment method with ascendant and descendent approach to threshold contrast adaptation on a computerized system of the Contrast sensitivity 8010 type were examined in patients before and 1 year after PRK. 20 emmetropes of the same median age were evaluated as a control group. 2. Preoperative BCVA and CS in myopes of all four groups was significantly lower (p < 0.05 az p < 0.001), compared to controls. Decrease of functions was proportional to refraction. 3. With increasing refraction less patients were within +/- 0.5 D and +/- 1.0 after surgery. 4. Twelve months after PRK, BCVA in the group A reached the level of controls, CS in the same time interval was equal to control even in groups A and B. 5. According to results of our study, PRK is a suitable method for myopia upto -6.0 D.

Adolescent↗
PubMed1999

[Hereditary occurrence of deep cavities in the optic nerve associated with Best's disease].

The authors present a pedigree where in three generations in male members deep excavations of the optic discs along with Best's disease of the centres in a variable form were recorded. The heredity is autosomal dominant. Retinal changes conditioned by defects of the pigmented epithelium reduce vision to a maximum of 6/60. The anomaly is associated with a pathological EOG record and normal ERG response. The observation is a contribution to discussions in the literature about the hereditary character of excavations of the optic nerve.

Adult↗
PubMed1998

Mechanical thrombectomy of massive pulmonary embolism using an Arrow-Trerotola percutaneous thrombolytic device.

Mechanical thrombectomy of a large central thrombus in massive pulmonary embolism is a new option for the treatment of this serious condition. The special mechanical devices designed to fragmentize a blood clot include the Arrow-Trerotola percutaneous thrombolytic device (PTD), the use of which in the pulmonary arteries has not yet been reported. The case of massive embolism into the left pulmonary artery with subsequent collapse is to demonstrate the immediately clinically successful treatment using the PTD. Our initial experience with the PTD shows that its use is a safe and quick procedure.

Angiography↗