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Biomedical subjects

J Rehák

Publications and source records attributed to J Rehák.

At least 19 recordsLinked to original sources
PubMed2006

[The ultrasound findings in posttraumatic endophthalmitis].

The aim of this study was to evaluate the ultrasound findings in eyes with endophthalmitis following penetrating injury and to establish unfavorable predictive signs of this serious disease. In a retrospective study we evaluated findings in 7 eyes of 7 patients followed up because of posttraumatic endophthalmitis at the Department of Ophthalmology, School of Medicine, in Olomouc, Czech Republic, EU, during the period September 1999-December 2004. The mean age of the patients was 37.3 years (range 22-49 years). The mean duration of the period between the injury and the formation of the endophthalmitis was 8.4 days (range 1-21 days). The visual acuity at the time of admittance was very low; it ranged between light perception and 1/60 (0,016 or 20/1200). All patients underwent diagnostic-therapeutic pars plana vitrectomy with vitreous samples taken for microbiological examination and intravitreal antibiotic application. The final visual acuity (VA) ranged from 1/60 (0,016 or 20/1200) to 6/12 (0.5 or 20/40), so it was very variable and that gave us the possibility to follow the connection between the final VA and seriousness of the penetrating injury, and also with the interval between the emergence of the endophthalmitis and beginning of its treatment. During the ultrasound examination, the presence of membranes in the vitreous body, posterior vitreous detachment, thickening of the choroid, detachment of the choroid and detachment of the retina were of concern to us. Membranes were present in the vitreous in 5 eyes. Without membranes detected by the ultrasound, there were 2 eyes; in both of them the final VA was better than 6/36 (0,1667 or 20/120). The posterior vitreous detachment was detected in 3 eyes, and not detected in four eyes. We didn't find any connection between the final VA and posterior vitreous detachment. The thickening of the choroid was present at the ultrasound examination in all seven eyes. The detachment of the choroid was not found in any eye. The retina was detached in two eyes. In three eyes only, the final central VA was better than 6/36 (0.1667 or 20/120). In two of them, the intraocular foreign body was found and in both the bacteria Staphylococcus epidermidis was detected. In the third eye, the soil bacteria Enterococcus and Klebsiela were cultivated. The ultrasound findings in these three eyes are identical only in the term of thickening of the choroid, similar to other eyes. In two of them no membranes were detected by ultrasound and no posterior vitreous detachment was found. The ultrasound examination in eyes with endophthalmitis after penetrating injury is specific in particular because of the mechanism of the injury. In contrast to the cases of the postoperative endophthalmitis, no prognostic unfavorable sings in the ultrasound examination can be strictly identified.

Adult↗
PubMed2006

[Ocular sparganosis in the Czech Republic--a case report].

The authors report a case of 14-year-old boy presented to the Ophthalmologic Department of University Hospital in Olomouc with the diagnosis af acute anterior uveitis. A living parasite has been detected in the anterior chamber in a slit lamp examination. The vitreous and retina remained uninvolved. The acute iridocyclitis associated with parasitic infection is a very rare cause of anterior uveitis in Central Europe. The patient underwent surgical removal of the parasite via paracentesis. The inflammation resolved under the treatment with atropine and dexamethasone drops within a few days. Histopathological examination revealed the parasite as a young larval stage of tapeworm from family Pseudophyllidea (sparganum). Based on the analysis of development cycles of different types of tapeworms and according the literature data on tapeworms found in the Czech Republic genus Spirometra seemed to be the most plausible cause of the patient's disease. As the most probable source of viable parasites authors suspect swallowed water containing tiny infected crustaceans in the dam near the town Olomouc in Moravia.

Adolescent↗
PubMed2005

[Early functional effect of the pars plana vitrectomy in complications of the proliferative diabetic retinopathy].

During the 1997-2002 period, 48 eyes of 41 patients of the mean age 58 years were operated on because of complications of proliferative diabetic retinopathy. In the cohort of operated patients, the type I diabetes mellitus was determined in 10 (21%) cases, the type II diabetes mellitus in 36 (75%) cases, and in two cases (4%), another type of diabetes was detected. One patient of those two had LADA type diabetes and the second one had secondary diabetes due to chronic pancreatitis. In the early postoperative period, or during first three months postoperatively, after the pars plana vitrectomy, the visual acuity (VA) in 28 (59%) eyes improved, in 16 (33%) eyes remained the same, and in 4 eyes (8%) worsened. VA 1/60 (0.017 or 3/200) and better had 37 (77%) eyes, VA 6/60 (0.1 or 20/200) and better had 17 (37%) eyes, and VA 6/12 and better (0.5 or 20/40) had 3 (6%) eyes only. VA worse than 1/60 (0.017 or 3/200) had 11 (23%) eyes. Authors emphasize the importance of regular and detailed ophthalmologic examinations with early diagnosis of pathological changes and early start of adequate treatment.

Adult↗
PubMed2005

Time precision of hippocampal CA3 neurons.

Time precision of generation of action potentials (AP) is limited by the electrical properties of neuronal membrane, by the probabilistic nature of synaptic transmission and by the membrane noise. In the software environment GENESIS 2.2, we constructed a multicompartmental model of a rat hippocampal neuron, made up of soma, dendritic tree and axonal initial segment (IS). In the model were implemented channel and thermal noise, corrupting the propagation of postsynaptic signal at the soma-dendritic (SD) membrane and the AP initiation at the IS. Various levels of synaptic redundancy, connecting the presynaptic neurons with the SD membrane by various numbers N of unreliable synapses of varying probability P of vesicle release, were modelled. During simulations, random spatio-temporal patterns of synaptic activity were presented to the neuron repeatedly, eliciting sequences of APs, which were further statistically processed. The influence of P, N, channel and thermal noise on the time precision of AP generation was tested by repeated stimulation of identical input. The precision was mostly influenced by the synaptic unreliability and substantially dependent upon values N and P. The channel noise was about an order less corruptive than the synaptic unreliability, causing the time precision of neuronal responses to vary from submilliseconds to tens of microseconds, depending on the values P and N.

Action Potentials↗
PubMed2004

[Argon laser photocoagulation in the therapy of the wet form of age-related macular degeneration].

The authors evaluate the results of argon laser therapy of extrafoveal and juxtafoveal subretinal neovascular membranes in the wet form of age-related macular degeneration. Their experience is evaluated in the group of 24 eyes of 23 patients during the period of observation lasting from 6 to 42 months. It became obvious that in the group of 24 eyes with extrafoveal and juxtafoveal subretinal neovascular membrane the laser photocoagulation cured up the condition in 17 eyes (71%), whereas the therapy failed in 7 eyes (29%). Vision improved in 7 eyes (29%), retained stabilized in 10 eyes (42%), but deteriorated in 7 eyes (29%). Among 11 eyes with extrafoveal subretinal neovascular membrane the authors reached improvement in 10 eyes (90.9%), the therapy failed with one eye (9.1%), the vision improved in 6 eyes (55%), remained stabilized in 4 eyes (36%), but deteriorated in one eye (9%). In 13 eyes with juxtafoveal subretinal neovascular membrane 7 eyes were cured up (54%), the therapy failed in 6 eyes (46%), vision improved in one eye (8%), remained stabilized in 6 eyes (46%), but deteriorated in 6 eyes (46%). Based on the results obtained it has become obvious that laser photocoagulation is a useful method for the therapy of extrafoveal and juxtafoveal subretinal nasovascular membranes in te age-related macular degeneration. Better prognosis has been shown in the extrafoveal subretinal neovascular membrane.

Aged↗
PubMed2004

[Personal experience in treatment of diabetic maculopathy].

The authors evaluate group of 111 eyes with diabetic macular edema treated by laser photocoagulation. The criterion to start laser therapy was biomicroscopically evident clinical significant macular edema. The visual acuity (VA) is evaluated during 1-5 years after the photocoagulation was started. The group with stabilized VA includes eyes with change of VA up to one line of Snellen optotypes. The groups with improved or worsened VA include eyes with change of 2 or more lines of Snellen optotypes. In the first year after the beginning of photocoagulation, VA in 87 eyes (78%) was stabilized, in 20 eyes (18%) improved, and in 4 eyes (4%) worsened. In the second year after the beginning of photocoagulation, VA in 85 eyes (77%) was stabilized, in 19 eyes (17%) improved, and in 7 eyes (6%) worsened. In the fifth year, VA in 82 eyes (74%) was stabilized, in 12 eyes (11%) improved, and in 17 eyes (15%) worsened comparing to the findings of first examination. It is evident from the study, the group with stable VA during the 5 years period changes a little bit, in the group with improved VA it is a perceptible decline from 18% to 11%. The most evident change is seen in the group with worsened VA--here we can notice an interesting conspicuous tendency of doubling the number of worsened eyes during each two years. Whereas 1 year after the beginning of the photocoagulation it consists of 4 eyes (4%) only, two years later, this is in the third year, it is 9 eyes (8%), and another two years later, thus 5 years after the beginning of photocoagulation it is already 17 eyes (15%). Very important finding is the low number of eyes in the group with worsened VA--together 7 (6%) at the examination performed 2 years after of the photocoagulation has been started because it is confirmed that in groups without treatment the number of eyes with worsened VA exceeds 50%. The photocoagulation near the center of the macula has to be performed with considerable caution--the authors have the experience that during several years after the photocoagulation the atrophic lesion enlarges up to twice its size to the original one, especially in older patients.

Diabetic Retinopathy↗
PubMed2004

[Ultrasound findings in endophthalmitis].

The ultrasound examination is the integral part of diagnostic procedure in endophthalmitis. During the ultrasound examination we may follow the organization of opacities in the vitreous, membranes formation, the thickening of the choroid, posterior vitreous membrane detachment, detachment of the choroid, the retinal detachment, chorideal abscess or granuloma, the edema of the optic nerve head and thickening of sclera. Not all of these ultrasound findings are always present. In our retrospective study, ultrasound findings of 17 eyes of 17 patients hospitalized at the Department of Ophthalmology at the School of Medicine, Palacký University in Olomouc during the period September 1999 - December 2002, were followed. Ultrasound findings in all eyes were evaluated and the final central visual acuity (VA) was followed. In eyes with VA 6/60 (20/200 or 0.1) or worse, the posterior vitreous membrane was not at all or only partially detached. In this group the finding of choroid thickening was more common. The finding of incomplete or absent posterior vitreous membrane detachment, and/or the thickening of the choroid might be prognostic unfavorable ultrasound finding in endophthalmitis.

Endophthalmitis↗
PubMed2002

[Treatment of central serous chorioretinopathy--personal experience].

On a group of 18 eyes the authors evaluate their experience with medicamentous and laser therapy of central serous chorioretinopathy. They report unsatisfactory results in the group of patients treated with non-steroid antiphlogistics, resorbents, vasoprotective agents, vitamins, where they observed adherence of ablated neuroepithelium in 4 eyes on average after 5.5 weeks. But in 7 similarly treated eyes adherence of the ablation did not occur even after 4 months. The authors confirm the value of direct laser photocoagulation for reducing the period of ablation in central serous chorioretinopathy. In all 11 photocoagulations of treated eyes the ablation adhered on average after 5.2 weeks. The authors maintain that they achieved better final visual acuity and greater improvement of visual acuity in patients where the ablation period of the neuroepithelium was shorter than in patients with a prolonged course of ablation.

Choroid Diseases↗
PubMed2002

[Treatment of central serous chorioretinopathy with beta blockers].

On a group of 13 eyes the authors evaluate their experience with medicamentous treatment of central serous chorioretinopathy. For treatment they used the non-selective beta-blocker Trimepranol, 2 x 5 mg/day. They found that in 11 eyes, in 84.6% cases, adherence of the ablated neuroepithelium of the macula occurred latest within four months of treatment, in two eyes (15.4%) this therapeutic dose did not lead to remission of the disease even after four months of treatment and the condition was evaluated as failure of treatment. The authors conclude that a therapeutic dose of Trimepranol of 2 x 5 mg/day is not a reliable therapeutic solution of central serous chorioretinopathy.

Adrenergic beta-Antagonists↗
PubMed2001

[Dr. Jan Vanysek: founder of the ophthalmology clinic in Hradec Kralove. A distinguished personality in Czechoslovak ophthalmology].

Professor Vanýsek was the first Czechoslovak ophthalmologist who overstepped the boundaries of the Republic and became one of the foremost scientist in ophthalmology. He was head of a department, consistent more with ideas of the 21st than 20th century. He founded two important ophthalmological school--in Hradec Králové and Brno. He laid the foundations for an experimental institute in Brno which would have become one of the foremost European institutions if Vanýsek had not been condemned by the totalitarian regime in the seventies.

Czechoslovakia↗
PubMed2001

[Personal experience in the treatment of proliferative diabetic retinopathy using an argon laser].

The authors evaluate the results of treatment of proliferative diabetic retinopathy by panretinal photocoagulation with an argon laser in a group of 122 eyes, 89 patients, with a mean follow-up period of 4.7 years. They achieved complete regression of revascularization of 69% eyes, partial regression in 21% eyes. In 10% eyes they treatment failed. The resulting visual acuity was 6/12 and better in 41% eyes, a visual acuity worse than 6/60 was recorded in 11% eyes. It remained unaltered in 70% eyes, deteriorated in 19%. The authors evaluated the success rate of laser photocoagulation in relation to the stage and site of neovascularizations. They found that the poorest reaction to panretinal photocoagulation is obtained in advanced neovascularization of the disc and they remain of the known view that advanced neovascularizations display a certain grade of autonomy which is the cause of a poorer response to panretinal photcogaulation. They confirm former observations that if signs of regression of neovascularization develop early, within 3-6 weeks after the onset of laser photocoagulation this may be considered a prognostically favourable sign.

Aged↗
PubMed2000

[Professor Václav Vejdovský--the man and his work].

Professor Václav Vejdovský, for many years head of the Olomouc Clinic, is a distinguished personality of Czechoslovak ophthalmology. He was head of the department for 42 years and created an important school of ophthalmology. He was one of the founding members of the Czechoslovak Ophthalmological Society and for many years its vie-chairman, in 1967-1970 its chairman. He represented Czechoslovakia in the committee of the European Ophthalmological Society. Professor Vejdovský has special merits as regards introduction of Czech nomencalture into previous almost exclusively German ophthalmology in Moravia.

Czech Republic↗
PubMed1994

[Cryotherapy in treatment of neovascular glaucoma with closed chamber angle].

BACKGROUND: The purpose of this study was to compare the clinical results of two cryosurgical methods in the treatment of neovascular glaucomas. PATIENT AND METHODS: In 43 eyes with acute neovascular glaucomas, cryosurgery was carried out. In 12 eyes, cyclocryocoagulation was performed as a single operation, whereas in 31 eyes transscleral panretinal cryocoagulation was combined with cyclocryocoagulation in one surgical session. The authors assess the effect of these two cryosurgical methods on the intraocular pressure, pain of the eye, visual acuity and neovascularization of the iris. RESULTS: The results of cyclocryocoagulation versus transscleral panretinal cryocoagulation in combination with cyclocryocoagulation were the achievement of an intraocular pressure up to 26 mmHg within 6 weeks after the operation: 5 (42%) v. 25 (81%), failure in reduction of the intraocular pressure: 4 (33%) v. 2 (6%), achievement of an only transient effect of reduction of the intraocular pressure: 3 (38%) (n = 8) v. 3 (14%) (n = 22). Regression of pain within 5 days postoperatively: 55% v. 100%. In five of six eyes, treated by application of the combined operation, the maintained visual acuity was 6/24-2/60 for a period of 6 months up to 1 year postoperatively. CONCLUSION: The method of transscleral panretinal cryocoagulation in combination with cyclocryocoagulation shows better results than the performance of cyclocryocoagulation only.

Cryosurgery↗
PubMed1993

[Retinal vein occlusion. I. Pathogenesis of circulatory changes].

In the pathogenesis of macular edema in venous occlusion of the retina, the majority of authors considers the high intracapillary pressure to be the decisive factor. The author's explanation is somewhat different and is based on two assumptions. The existence of the vascular autoregulatory mechanisms of the retina and the so-called disproportion between the arterial and the venous volume. When the critical level of the disproportion of the arterial and the venous volume is surpassed, the retinal autoregulation begins to fail which manifests itself by a marked retinal edema and an essential decrease in visual acuity.

Edema↗
PubMed1993

[Retinal vein occlusion. II. Collateral systems].

During the period of 6-12 months, in the majority of patients with occlusion of the branch of the retinal vein, the macular edema regresses and the intraretinal hemorrhages are resorbed. According to the author, this restoration of the circulatory conditions in the retina takes place especially due to the development of the veno-venous collaterals. The author presents an explanation of the mechanism of the regulation of the circulatory conditions in the retina during the development of the collaterals on the basis of the new approach to the explanation of the pathogenesis of the circulatory changes in occlusion of the branch of the retinal vein.

Collateral Circulation↗