On Unconstrained SU(2) Gluodynamics with Theta Angle

The Hamiltonian reduction of classical SU(2) Yang-Mills field theory to the equivalent unconstrained theory of gauge invariant local dynamical variables is generalized to the case of nonvanishing theta angle. It is shown that for any theta angle the elimination of the pure gauge degrees of freedom leads to a corresponding unconstrained nonlocal theory of self-interacting second rank symmetric tensor fields, and that the obtained classical unconstrained gluodynamics with different theta angles are canonically equivalent as on the original constrained level.Comment: 13 pages Revtex, no figures; several misprints corrected; version to appear in Eur. Phys. J.

Laser therapy in ROP: a literature review and our experience

Introduction: Retinopathy of prematurity (ROP) is a serious, vision threatening disease and among the leading causes of irreversible loss of vision. It affects prematurely born children, predominantly prior to the 32nd GW or with a body weight at birth below 1500 g. The highest risk for the development of ROP includes the time period of two weeks before to two weeks after the supposed due date. Materials and Methods: We included 10 prematurely born children with ROP requiring therapy. All of the children were screened by indirect ophthalmoscopy and the condition was documented by RetCam imaging. The treatment was conducted by the application of 810 nm diode laser. Results: Nine out of the 10 children were born before 32 GW and were with a body weight at birth below 1500 g. The disease was bilateral in 9 of the children. Laser therapy was applied to all 10 children and 18 eyes. Discussion and Conclusion: The active ophthalmological screening of all children born before 32 GW and with a body weight at birth below 1500 g, including all new-born children at risk, and the application of early laser treatment are the basis for the prevention of the development of irreversible visual loss

Identifying Place Histories from Activity Traces with an Eye to Parameter Impact.

Events that happened in the past are important for understanding the ongoing processes, predicting future developments, and making informed decisions. Important and/or interesting events tend to attract many people. Some people leave traces of their attendance in the form of computer-processable data, such as records in the databases of mobile phone operators or photos on photo sharing web sites. We developed a suite of visual analytics methods for reconstructing past events from these activity traces. Our tools combine geocomputations, interactive geovisualizations, and statistical methods to enable integrated analysis of the spatial, temporal, and thematic components of the data, including numeric attributes and texts.We also support interactive investigation of the sensitivity of the analysis results to the parameters used in the computations. For this purpose, statistical summaries of computation results obtained with different combinations of parameter values are visualized in a way facilitating comparisons. We demonstrate the utility of our approach on two large real data sets, mobile phone calls in Milano during 9 days and flickr photos made on British Isles during 5 years

Pseudostrabismus, masking manifest strabismus

Въведение: Често диагнозата страбизъм е "изписана на лицето", особено при голям ъгъл на отклонение.Въпреки това диагностичната дилема с риск от хипердиагностика е налице, особено при деца с епикантус, телекантус, положителен или отрицателен ъгъл капа. Обратно, в някои случаи без козметичен вид на кривогледство, се установява дълбоко разстройство на бинокулярното зрение (анормална ретинена кореспонденция, амблиопия, централен скотом, редуцирана стерео острота) - микрострабизъм.Псевдострабизмът може да съществува едновременно с истински страбизъм, като козметично го неутрализира, преувеличава или дори създава илюзия за кривене в обратна посока.Цел: Да покажем интересни случаи с псевдострабизъм, съществуващ едновременно с истински страбизъм.Материал и методи: Представени са два клинични случаи на деца с регресирала форма на ретинопатия на недоносените (РН, ROP) и положителен ъгъл капа в резултат от ектопия на макулата. Използвани са офталмологични и артоптични методи.Резултати: В единия случай псевдоекзотропията козметично компенсира напълно съществуващата истинска есотропия, a в другия случай при наличие на голям ъгъл есотропия, козметичният вид е на екзотропия.Заключение: Децентрацията на корнео-фовеоларният рефлекс по Хиршберг не доказва страбизъм, нито измерва ъгъла на кривене. Диагнозата за истинска хетеротропия или хетерофория се поставя след cover/uncover тест. Така може да се натъкнем на съществени разлики между видимото и истинско кривене. Правилната диагностика е важна за правилното ортоптично и хирургична лечение на страбизма.Introduction: The diagnosis strabismus is often "written on the face", especially in cases with large angle of deviation. Nevertheless, the diagnostic dilemma with a risk of hyperdiagnosis is present, especially in children with epicanthus, telecanthus, positive or negative kappa angle. Conversely, in some cases without a cosmetic appearance of squinting, there is a severe impairment of binocular vision (abnormal retinal correspondence, amblyopia, central scotoma, reduced stereo vision) - microstrabismus. Pseudostrabismus may coexist with real strabismus, cosmetically neutralizing it, exaggerating it or even creating an illusion of squinting in the opposite direction.Objective: To report interesting cases with pseudostrabismus, coexisting with real manifest strabismus.Material and Methods: We present two clinical cases of children with cicatricial retinopathy of prematurity (ROP) and positive angle kappa, resulting from ectopia of the macula. We use ophthalmic and ortoptic methods.Results: In one case the existing real esotropia is fully cosmetically compensated by pseudoexotropia. The other case has cosmetic appearance of exotropia, while a large angle of esotropic deviation is present on cover/uncover test.Conclusion: Decentration of the corneo-foveal reflex (Hirshberg) does not diagnose strabismus, nor it measures the angle of deviation. Diagnosis for real heterotropia or heterophoria is done only after cover/uncover test. Thus, we may encounter significant differences between visible and real squinting. Correct diagnosis of strabismus is important for the right ortoptic and surgical treatment

Retinoblastoma – a literature review and our experience

Retinoblastoma is the most common malignant eye tumor in children that is lethal if left untreated. The contemporary treatment modalities aim not only to save life, but also to preserve the eyes as an organwith form vision and the wich would greatly reflect on the quality of children’s lives. Historically, enucleation was the first successful therapeutic approach to reduce mortality, followed more than 100 years ago by the radiation therapy as the first attempt to save the eyes. Over the last two decades, conservative treatment of retinoblastoma has undergone an impressive development, allowing complete cure with minimal sequelae when timely diagnosed and treated. Today’s treatment protocol includes combination of selective chemotherapy, radiation therapy, laser therapy and, if necessary, systemic chemotherapy. The goal of this article is to review the up-to-date conservative management of retinoblastoma and to emphasize the importance of general practitions and pediatricians for timely diagnosis

Coats disease ‒ case report

Coats disease is a rare, in about 90% of cases unilateral idiopathic eye pathology. It is characterized by telangiectatic and aneurysmally altered retinal blood vessels and progressive intra- and subretinal exudation, which can lead to exudative retinal detachment. Most often the symptoms manifest in the advanced stages. Purpose: To report a case with Coats disease. 10 year old boy, admitted to the Eye Clinic of the University Alexandrovska Hospital – Sofia, with leucocoria and strabismus of the right eye. Method: Full ophthalmic and orthoptic examination, OCT. Results: 3B stage of Coats disease of the right eye was established. The chance for improvement after surgery was evaluated as very little, so our patient remained under observation with protective glasses and prevention of complications. Conclusion: It is of great importance to early diagnose the disease, so to have more treatment options

Functional endoscopic sinus surgery (FESS) with navigation system in childhood – our experience. Presentation of clinical cases

Introduction: Functional endoscopic sinus surgery (FESS) is the gold minimally invasive standard in diagnosing and surgically treating many diseases of the nose and paranasal cavities. An advantage of FESS is the possibility of application in all age groups.Materials and methods: We observed pediatric patients attended the Otorhinolaryngology Clinic in the University Hospital “Dr. Georgi Stranski” – Pleven in 2021. FESS surgery was performed in the “Integrated interdisciplinary operating unit with navigation and telesurgery systems” at the Center of competence on personalised medicine, 3D and telemedicine, robotic and minimally invasive surgery „Leonardo da Vinci” in Medical University – Pleven.Clinical cases: Case 1: A 7-year-old male patient with orbital complication of rhinosinusitis, with left orbital preseptal cellulitis, without ophthalmoplegia or loss of vision, + ptosis of the eyelid and data on pansinuitis from CT images. Performed FESS found lysis of lamina papyracea with involvement of anterior and posterior ethmoidal cells. Postoperative treatment was done with Ceftriaxone 1g/12h i.v. for 7 days, nasal glucocorticoids and antihistamines.Case 2: A 17-year-old female patient with suggested primary ciliary dyskinesia with a recurrent rhinosinusitis, persistent nasal obstruction, and thick viscous secretions that did not respond to conservative treatment. Sweat test for cystic fibrosis (-). FESS reshaping of the natural openings of the maxillary sinuses and anterior ethmoidectomy were performed bilaterally.Conclusion: FESS is a minimally invasive method, which is suitable for application in pediatric patients. When applied by trained professionals, FESS with an integrated navigation system is optimal for the diagnosis and surgical treatment of chronic and acute rhinosinusitis in children

Our experience in the surgical treatment of Obstructive Sleep Apnea

Background: Obstructive Sleep Apnea (OSA) is a sleep-related breathing disorder, leading to decreased quality of life, increased risk of cardiovascular morbidity and mortality, increased frequency of automobile accidents. Continuous positive airway pressure (CPAP) remains the first line of treatment for OSA. Many patients are unwilling or incapable to tolerate the treatment and therefore turn to surgical options to alleviate symptoms and sequela of the disease.Аim: To present our experience in the surgical treatment of OSA.Materials and Methods: 50 patients (48 male / 2 female) underwent surgical treatment for OSA in our clinic for a period of 10 years. Subjective complaints were evaluated by interview of the patient and partner pre- and postoperatively, with key factors studied being snoring level (visual analogue 1–10) and Epworth Sleepiness Scale (ESS). Objective data were Body Mass Index (BMI), nasal endoscopy, pre and postoperative polysomnographic data, rhinomanometry, Mallampati score, diagnostic imaging of the nose and sinuses.Results: The mean BMI of the patients was 29.8± 3.4. 21 patients had nasal obstruction for which they underwent surgical treatment. 5 patients had micro or retrognathia. 37 Pateints had a Mallampati score of 3 and 13 of 4. All 50 patients underwent Uvulopalatopharyngoplasty (UPPP) and 6 patients also had Radiofrequency tongue base reduction. There were no serious complications. Subjective improvement in the severity of the symptoms was obtained in 88% (44) of patients. Objective success was obtained in 56% (28) of the patients.Conclusions: Surgical treatment of OSA leads to a significant subjective improvement in the severity of symptoms and acceptable objective results. For maximal results a multidisciplinary approach is required for the complex treatment of OSA

Vitamin D status in children with myopia

Introduction. A dramatic increase of myopia worldwide has been observed in recent years. New risk factors for the development of myopia have been the target of numerous investigations. The basis of our research is the correlation between serum levels of vitamin D [25(OH)D] and myopia itself.Purpose: To find out the relationship between serum levels of 25(OH) D and myopia. Patients and methods: The study included 222 children with different refraction status. Full ophthalmologic examination, cycloplegic refraction, echobiometry were performed. The serum levels of 25(OH)D were measured by liquid chromatographic mass spectrometry (level of insufficiency < 80 nmol/L).Results: The average patients’ age (51% boys and 48,2% girls) was 11,7 y (SD ± 3,03). They were subdivided into two groups – children with myopia (84,7%) and those without myopia (15,3%). The mean serum 25(OH)D level of all tested was 61,48 nmol/L (16-140 nmol/L; SD ± 20,15); of myopia – 59,67 nmol/L (16-140 nmol/L; SD ± 19,30) and of the non-myopia group – 71,91 nmol/L (33-111 nmol/L; SD ± 21,79). There was a statistically significant difference in serum levels between the two groups (Р = 0,001). The risk of myopia was higher with the decrease of 25(OH)D values (OR = 1,028 ; 95% CI 1,008-1,048). Conclusion. In our investigation group we established low serum levels of 25(OH)D which indicated the need for conducting a population study of its status among Bulgarian children. The correlation between the higher risk of myopia and the vitamin D scarcity has to be further studied, also considering the factor of outdoor/sun-exposure time.