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Stefan M Pojda

Publications and source records attributed to Stefan M Pojda.

At least 19 recordsLinked to original sources
PubMed2006

[The influence of dopamine injected into the lateral geniculate body on flash visual evoked response in rats].

PURPOSE: Numerous neurotransmitters and neuromodulators operating on all levels of the visual system, influence the parameters of cortical evoked response. The aim of this study was to find the influence of dopamine (DA) injected into the lateral geniculate body (nucleus) on flash visual evoked response (FVEP). MATERIAL AND METHODS: The experiments were performed on adult Wistar rats. They were implanted with 1 caniula conducted into the lateral geniculate body and 2 electrodes: active under the skull on dura mater in occipital region of brain and reference one on the skull in the interorbital region. FVEPs curve before and after injection into the lateral geniculate body 0.9% NaCl and DA were analyzed. RESULTS: DA in the lateral geniculate body causes increasing latency and amplitude of FVEP peaks. CONCLUSIONS: Dopamine in the lateral geniculate body can improve visual perception in the occipital cortex.

Animals↗
PubMed2006

[The influence of stimulation dopaminergic D, i D2 receptors in lateral geniculate body on flash visual evoked potentials (FVEP) in rats].

PURPOSE: The topic of this paper is to define the influence of stimulation dopaminergic D1 i D2 receptors in lateral geniculate body by flash visual evoked potentials (FVEP). MATERIAL AND METHODS: Wistar rats were examined. There were stereotaxically implanted with guide caniula into the lateral geniculate body to inject substances and with VEPs electrodes on the skull and on the surface of visual cortex. VEPs curve before and after injection into the lateral geniculate body: 0.9% NaCl, agonists of dopamine receptors D1 - SKF 38393, and D2 Quinpirole and also the same agonist after antagonists D1 - SCH 23390, i D2 Sulpiride were analyzed. RESULTS: Stimulating receptors D1 in the lateral geniculate body cause amplitude increase and shortness of latency. Quinpirole, agonist of D2 receptor do not significant change FVEPs curve. CONCLUSIONS: Stimulation of D1 receptors in the lateral geniculate body can improve visual transmission throught it and response in the occipital cortex.

Animals↗
PubMed2005

[Flash full-field electroretinography in diseases with night blindness].

PURPOSE: The aim of this study is to present similarities and differences of electroretinograms in early stages of retinal diseases with nyctalopia. MATERIAL AND METHODS: Flash full-field electroretinography was done according to ISCEV standards and also with chromatic stimulations in patients with nyctalopia, who were diagnosed as various forms of congenital stationary night blindness and various types of retinitis pigmentosa, choroideremia, gyrate atrophy and also in patients with nyctalopia, because of unknown reason. ERG results were compared with normal values and with each other. RESULTS: In diseases with nyctalopia the function of peripheral retina is markedly abnormal and scotopic ERG is significantly reduced or even absent. In retinitis pigmentosa a-wave is small or absent especially scotopic but photopic ERG is also abnormal. Well preserved a-wave distinguished ERG of patients with stationary night blindness from the other progressive diseases of retina or choroid. CONCLUSIONS: In patients with nyctalopia using ERG is possible to obtain which retinal elements do not work but it is only start point to following diagnostic examinations, to make proper final diagnosis.

Adolescent↗
PubMed2005

[Quality of life in patients suffering from choroideremia].

PURPOSE: To direct attention on every-day problems in choroideremia, which are not a barrier in patients occupation. MATERIAL AND METHODS: Two cases of patients with choroideremia which was diagnosed when they were 30 and 54 are described. In spite of widespread visual field changes patients with good visual acuity did not have to change their lifestyles or their jobs (miner and mechanic). Visual acuity, visual field, mesoptometry, adaptometry, electroretinography, electrooculography were done. The mother of the younger patient was also examined. Her fundus of the eye showed typical changes for carriers. In the older patient's family among 41 family members 7 men were affected in 3 generations. Follow-up was 6 years. RESULTS: In ERG rod activity was very low or abolished and cone activity was reduced, more in older patient. In the younger patient visual acuity and mesoptometry were normal, rod adaptation was very low. The patient was able to work as a miner due to good mesopic vision. In follow-up no significant progression of the disease was observed. The older patient had previously been treated for retinitis pigmentosa for a few years. Diagnosis of choroideremia was made when visual acuity of the patient declined. It was impossible to perform mesoptometry and adaptometry because of advanced night blindness. In the dark room the patient found it very difficult to move. In follow-up lowering of the visual acuity, progression of visual field as well as electroretinographic changes occurred. CONCLUSIONS: Patients with choroideremia may be professionally engaged despite of every-day problems connected with widespread scotomas in visual field and nyctalopia. They should not become pensioners too early. The disease progression is faster in older than in younger patients.

Adult↗
PubMed2005

[Influence of prenatal exposition for selenium on visual evoked potentials (FVEP) in rats].

Selenium is an essential trace element in lower concentration and toxic in higher one. The aim of the study was to find out if the small doses of selenium taken by pregnant rats change the visual evoked potential (FVEP) curve in newborns. The FVEP was done in 4-6 month old white, Wistar, offsprings rats. 8 rats were from the mothers which drank water solution of natrium selenosum in dose 1.5 ppm through the whole pregnant time ( selen group) and 8 rats were from the pure farm (control group). The shortened of the latencies and increased of the amplitudes of N1 and P1 waves were observed in the selenium exposed group in comparison to the control, but only the changes between amplitudes of N1 and P1 were statistically significant. The small doses of selenium by improving the VEP may probably change for the better vision too.

Animals↗
PubMed2005

[Ocular complications in course of idiopathic retroperitoneal fibrosis].

Idiopathic retroperitoneal fibrosis is a rare collagen vascular disease of still unclear, immunological etiology. One of the first descriptions of this pathology was derived from Ormond and the Ormond's disease became its second name. It is characterized by a chronic, non-specific inflammation of the retroperitoneum, which obstructs retroperitoneal structures. The most frequent complication is the ureteric obstruction with hydronephrosis and renal failure. The fibrotic process may develop in different, even remote sites, including ophthalmic system. We have presented a 50-year-old woman with Ormond's disease and anterior uveitis. We have also described the other ocular complications of this disease.

Female↗
PubMed2005

[Intraorbital foreign body--three years follow-up].

A case of patient with metallic intraorbital foreign body, was described. The foreign body went trough the eye and finally was situated close to the optic nerve. After three years, no signs of siderosis were found (ERG). The patient is still under control.

Adult↗
PubMed2005

[Visual evoked potentials (FVEP) after the prenatal exposure to heavy metals--experimentals studies].

PURPOSE: To find out, if any and how deep alterations in visual tract are due to prenatal intoxication by heavy metals such as: cadmium (Cd), lead (Pb), mercury (Hg) and manganese (Mn). The measure of these alterations were the changes in flash visual evoked potentials after prenatal intoxication. MATERIAL AND METHODS: The experiments were carried out on 55 white newborns Wistar rats, which were divided into 5 groups: control group (14 rats), Cd group (12), Pb (6), Hg (14) and Mn (9). The method of the FVEP study was described by Pojda et al. RESULTS: The latencies of the peaks N1 and P1 were prolonged in the Mn group till 113-118% (p< 0.05). Slight prolongation of N1 latencies about 1% in Cd and Hg groups and of 4% in Pb group were not statistically significant. The differences of P1 latencies were not statistically significant in these groups, compared to the control group. The amplitude of N1 wave decreased in Cd group about 63% and in Mn group of 32% compared to the control (p<0.05). In Hg intoxicated group the N1 amplitude decreased to 56% (p< 0.01). The amplitude of P1 decreased in all intoxicated groups (Hg of 56%, Cd 55%, Mn 49%) statistically significant, except the Pb one, in which even 21% decrease was not significant. CONCLUSIONS: The heavy metals prolonged the latencies and diminished the amplitudes of flash visual evoked potentials, so may be, they are not only neurotoxic but also "ophthalmotoxic" factors.

Administration, Oral↗
PubMed2005

[The function of eye and vision system in children and youth treated with vigabatrin--our own experiences].

PURPOSE: The aim of this study is to find the relationship between visual function changes and vigabatrin treatment continuation or discontinuation. MATERIAL AND METHODS: 19 patients (11 males, 8 females) from 8 to 20 years old, treated with vigabatrin because of partial epilepsy, were examined. Best corrected visual acuity, contrast sensitivity and static visual field were done. The examinations were repeated after 1-2 months and after 1-2 years. The longest follow-up was about three years (one girl). In some children from this group additional elctrophysiologic tests (ERG, EOG according to ISCEV standards), were done. RESULTS: Corrected visual acuity was 5/5 in all eyes. Contrast sensitivity was normal and it was not changed in follow-up period. Abnormal visual field was found in more than half of examined patients. The improvement of visual field occurred after vigabatrin discontinuation, but in one patient the improvement occurred although vigabatrin treatment was continued. Most of the patients refused control ERG and EOG, but in first examination decreased or border b-wave amplitude after "flicker 30Hz" was found. CONCLUSIONS: In some patients treated with vigabatrin reversible visual field changes occurred. Multicentre study should be performed, to solve the problem of relationship between visual field changes, vigabatrin and other antiepileptic treatment. All tests in group of epileptic patients are difficult because of poor cooperation.

Adolescent↗
PubMed2004

[Sudden blindness of 11-year old boy in the course of acute lymphoblastic leukemia].

PURPOSE: The aim of this study is to present dramatic ocular manifestation of acute lymphoblastic leukemia. MATERIAL AND METHODS: The 11 years old boy was hospitalized due to acute leukemia at the Department and Clinic of Pediatric Hematology, and was referred to ophthalmic examination because of sudden blindness of the right eye. General ophthalmic examination and electrophysiological tests were done. RESULTS: No light perception of right eye, and markedly reduced visual evoked responses were caused by infiltration with great edema in optic nerve and its surrounding of retina. In spite of the fact, that the infiltrations disappeared after general therapy, the vision did not recover at all. CONCLUSIONS: Even intensive treatment may be ineffective in blindness prevention in severe course of acute leukemia.

Blindness↗
PubMed2004

[Short wavelength perimetry--the significance in diagnosis of glaucoma in myopic patients].

The static perimetry is the most useful diagnostic method in glaucoma. The aim of this paper is to compare the results of static short wavelength automatic perimetry (SWAP) with the classic one (white) in myopic patients with and without glaucoma. The Tubingen Automatic Perimeter was used, the threshold strategy within the central 30 degrees and glaucoma program was performed. The sensitivity of the retina in blue on yellow perimetry was nearly two classes lower than in the classic method in both groups. The enlargement of the blind spot and the appearance of the arcuate relative scotomas could be shown in SWAP, while classic perimetry is still normal. Both, the mean defect (MD) and the mean sensitivity (MS) in SWAP indicated for the very early glaucomatous changes in myopic patient, too. The changes of the loss variance (LV) was not characteristic for these patients.

Adolescent↗
PubMed2004

[Optic disc drusen and glaucoma--case report].

Optic disc drusen make examination towards glaucoma difficult to interpret. They change nerve head morphology and visual field defects can resembling glaucomatous damage. Patient with strong headache was examined and we found drusen on both optic nerve heads and intraocular pressure about 27 mmHg. Visual fields demonstrated scotomas--in lower half and the enlargement of the blind spot. After topical treatment and intraocular pressure normalization, the patient's complaints had gone. Control examination after one year revealed progression of visual field changes. Electrophysiological examination showed abnormalities typical for glaucoma.

Adolescent↗
PubMed2004

[The intracranial hypertension in the course of Arnold-Chiari malformation].

PURPOSE: The aim of this study was to remind the symptoms and diagnostic methods helpful to recognize Arnold Chiari syndrome. MATERIAL AND METHODS: We have presented a 53-year-old woman with papilledema who was operated and treated oncologically because of right breast tumor - four years ago. As a result of diagnostic research which took into consideration a brain magnetic resonance imaging (MRI), the suspicion of metastatic cerebral tumor was excluded and Arnold - Chiari malformation was diagnosed. CONCLUSIONS: The intracranial hypertension and it's ocular manifestation - papilloedema may be caused by different, also congenital, reasons. The brain MRI is the mainly procedure to diagnose the Arnold - Chiari malformation.

Arnold-Chiari Malformation↗
PubMed2004

[Acute endophthalmitis of 15-year old boy in the course of acute lymphoblastic leukemia--part I].

PURPOSE: The aim of this study is to present dramatic ocular manifestation of acute lymphoblastic leukemia. MATERIAL AND METHODS: 15-year old boy was hospitalized due to acute leukemia at the Department and Clinic of Pediatric Hematology and was referred to ophthalmologist because of strong pain and decreased visual acuity of the left eye. General ophthalmic examination and electrophysiology were done. These procedures were repeated after 1, 2, 5 and 11 weeks and also after 6 and 9 months. RESULTS: Acute uveitis with cellular exudation to the vitreous, papilledema, swelling of the macula and green-yellowish infiltration which elevated the temporal part of the retina, were noticed. Swelling of the iris and miosis were observed. After one week of local anti-inflammatory treatment the eye became painless with little deep injection only. Simultaneously causal treatment of basic disease was continued. Control examinations revealed step by step improvement of ocular changes. After 6 months in the place of retinal infiltration choroidoretinal atrophy was seen. The functional deficits in visual field and electrophysiological examinations were found, too. One year later, the patient came again because of recurrence. Involvement of the central nervous system with signs of meningitis occurred. Visual acuity was normal and no infiltration of eyes was found, but there was papilledema in both eyes. CONCLUSIONS: In acute leukemia ocular manifestation may be highly expressed. The patients require local symptomatic and general causal treatment in cooperation of ophthalmologist with hematologist.

Acute Disease↗
PubMed2004

[Acute endophthalmitis of 15-year old boy in the course of acute lymphoblastic leukemia. Part II--Electrophysiological examinations].

PURPOSE: The aim of the study is to present objective estimation of visual function in eyes affected by leukemia. MATERIAL AND METHODS: The boy who was described in the first part of this study was examined. Visual evoked potential (VEP), full-field flash electroretinography (FERG), electrooculography (EOG), were done according to ISCEV standards. RESULTS: The function of retina was decreased proportionally to the areas of infiltration. The amplitude of VEP peaks was lowered when the involvement of the central nervous system occurred. In the eye with retinal infiltration abnormal EOG was present a few months earlier than pigment epithelium destruction was seen in ocular fundus. CONCLUSIONS: Functional deficits may be irreversible.

Acute Disease↗
PubMed2002

[The long term clinical outcome of anterior chamber lenses after cataract surgery].

PURPOSE: To analyse the functional results and postoperative complications of primary and secondary anterior chamber lenses implantation in a follow up of 10 years. PATIENTS AND METHOD: Sixty one patients (64 eyes), 29 females and 32 males, between 22 and 96 year of age (midding 64 years), who underwent cataract surgery with anterior lens implantation from 1990 to 2000 were analysed. It was performed with cataract removal in 51 eyes (after intracapsular extraction in 18 eyes and 33 eyes with intraoperative complications making impossible to apply the posterior chamber intraocular lens). The secondary implantation was complied in 13 aphakic eyes from 1 to 13 years after cataract removal. Thirty nine patients were subjected to the control examination on October of 2000 year. The visual acuity, intraocular pressure, anterior and posterior part of the eye were examined. RESULTS: The satisfactory visual function and intraocular pressure were confirmed in most of the patients. The reasons of lower visual acuity were: the retinal detachment (2 eyes), bullous keratopathy (2 eyes after vitreous loss), age related macular degeneration (1 eye), proliferative diabetic retinopathy (2 eyes). In the anterior part of the eye in 21 eyes (54%) we observed deformation of the pupil's shape, only. CONCLUSIONS: The anterior chamber lens implantation is an efficacious method of aphakia treatment in some patients. The older patients demonstrated good functional results and tolerance of anterior chamber lens, especially after the cataract removal by krioextraction. The good tolerance and visual acuity were observed either in cases of primary or secondary implantation. In the case of capsular rupture and vitreous loss before AC IOL implantation, a complete (full) vitrectomy should be performed.

Adult↗
PubMed2002

[Flash visual evoked potentials (FVEP) examination under midazolam sedation of non-cooperating children].

PURPOSE: To find the optimal conditions for visual evoked potential (VEP) examination of non-cooperative children using midazolam maleate sedation. PATIENTS: 32 children aged from 8 months to 13 years (mean 3.5 years) with mental disorders, emotional problems and/or very low vision due to various reasons. METHODS: VEP--flash and bright flash according to ISCEV standards. Midazolam maleate sedation 0.4-0.5 mg per kilo body weight, given orally. RESULTS: Only 6 children aged from 11 months to 3.5 years (mean 2.5 years) required sedation for VEP examination. Midazolam sedation unabled VEP examination, was safe for children and well-tolerated. CONCLUSION: Second degree sedation in Ramsey score is effective for good VEP examination of non-cooperative children.

Anxiety↗