1,720,961 research outputs found
Bilateral angle-closure during hospitalization for coronavirus disease-19 (COVID-19): A case report
No full textPurpose: This report describes a case of bilateral primary angle closure (PAC) progressing to unilateral end-stage primary angle closure glaucoma (PACG) associated with treatment for coronavirus disease-19 (COVID-19) infection. Methods: A 64-year-old man came to our attention because of blurred vision after a 2-month hospital stay for treatment of COVID-19 infection. Examination findings revealed PACG, with severe visual impairment in the right eye and PAC in the left eye due to plateau iris syndrome. The patient's severe clinical condition and prolonged systemic therapy masked the symptoms and delayed the diagnosis. Medical chart review disclosed the multifactorial causes of the visual impairment. Ultrasound biomicroscopy (UBM) aided in diagnosis and subsequent therapy. Results: The cause behind the primary angle closure and the iridotrabecular contact was eliminated by bilateral cataract extraction, goniosynechialysis, and myotic therapy. Conclusions: COVID-19 treatment may pose an increased risk for PAC. Accurate recording of patient and family ophthalmic history is essential to prevent its onset. Recognition of early signs of PAC is key to averting its progression to PACG
Pediatric glaucoma: current perspectives
Full text linkGiorgio Marchini, Marco Toscani, Francesca Chemello Eye Clinic, Department of Neurological and Movement Sciences, University of Verona, Verona, Italy Abstract: “Childhood glaucoma” is a heterogeneous group of severe pediatric conditions often associated with significant visual loss and characterized by elevated intraocular pressure (IOP) and optic-disk cupping. Successful IOP control is crucial but challenging and most often achieved surgically, with medical therapy playing a supportive role. There are many classifications of childhood glaucoma, but they can simply be divided into primary, in which a developmental abnormality of the anterior chamber angle only exists, and secondary, in which aqueous outflow is reduced due to independent mechanisms that secondarily impair the function of the filtration angle. The worldwide prevalence of childhood blindness ranges from 0.03% in high-income countries to 0.12% in undeveloped countries. The majority of cases do not have an identified genetic mutation and, where the mutation is known, the genes often account for only a small proportion of cases. Several pathogenetic mechanisms are known to contribute to the development of childhood glaucoma. Whatever the cause, it results in a reduced aqueous outflow at the level of the trabecular meshwork. Age of onset and magnitude of the elevated IOP largely determine the clinical manifestation the high variability of clinical manifestations. Glaucoma from any cause in a neonate and infant is characterized by the classic triad of epiphora, photophobia, and blepharospasm, and could be associated with eye enlargement (buphthalmos) and Haab striae. The eye examination, usually performed under general anesthesia, includes: tonometry, anterior-segment examination, gonioscopy, corneal diameter and axial length measurement, dilated fundoscopy with optic-nerve-head evaluation. Medical therapy, considering the high frequency of side effects, is generally used as temporizing IOP-lowering treatment before surgery or as adjuvant treatment postoperatively in case of partially successful procedures for refractory glaucomas. Surgery is the nodal point of the management of refractory childhood glaucoma, so it is crucial to opt for a forward-looking strategy to reach the target IOP and minimize the visual loss. Keywords: childhood glaucoma, congenital glaucoma, glaucoma surgical therapy, childhood visual los
Primary congenital glaucoma surgery: outcomes and visual function
Full text linkPurpose: To assess the long-term visual outcomes of children with PCG, irrespective of the type of surgical procedure, and to create visual acuity curves to help in predicting the development of visual function in these patients. The secondary aim is to identify associated factors for visual decline or loss, highlighting differences between neonatal and infantile subgroups. Methods: The medical records of pediatric glaucoma patients from 1996 to 2017 at the University Hospital of Verona (Verona, Italy) were retrospectively reviewed. Visual acuities, surgeries, PCG subtype and etiology of vision impairment were recorded. Statistical analyses were performed to detect factors associated with vision decline. Results: Sixty-seven eyes (40 patients) were included in the study. Developmental predictive curves of visual acuity showed that children with infantile PCG had a better visual outcome than children with neonatal PCG at each step of follow-up. A good-to-moderate VA (< 1 LogMAR) was achieved in 56 eyes (83.6%), while 11 eyes (16.4%) had poor VA (≥ 1 LogMAR). The age at onset, sex, number of surgeries, intraocular pressure (IOP) control (with or without antiglaucoma drugs), axial length (AL) and corneal opacities were statistically associated with vision impairment (p < 0.01). The main cause of visual impairment was amblyopia. Conclusions: Visual outcomes of PCG significantly correlate with the age at diagnosis. Although a good long-term IOP control can often be achieved in PCG, often the visual acuity remains below the lower limits of the normal range. Poor vision in childhood is related to global developmental problems, and referral to third-level services should not be delayed to prevent vision impairment. In this regard, visual acuity curves can be a useful tool for the consultant ophthalmologist to define the visual development of children affected by PCG
Confronto tra tonometro ICARE e tonometro di Goldmann in pazienti con glaucoma primario ad angolo aperto e ipertensione oculare semplice
No full text[no abstract available
Double versus single suture stenting to manage hypertensive spikes after glaucoma drainage device implantation
No full textPurpose: To evaluate the safety and efficacy of double compared to single intraluminal suture stenting in reducing early postoperative hypertensive spikes (HS) and hypotony after Baerveldt glaucoma implant surgery. Methods: For this retrospective study, we reviewed the medical charts of 60 patients (60 eyes) who underwent Baerveldt drainage device surgery between 2017 and 2019. Two groups were formed according to whether a single suture stent was placed within the tube (5-0 polypropylene, 30 eyes, group 1) or a double suture (5-0 and 6-0 polypropylene, 30 eyes, group 2). Intraocular pressure (IOP) was measured at baseline, at 6 h, and on postoperative days 1, 2, 5, 7, 14, 21, 30, 60, 90, 180. The occurrence of HS (IOP ⩾ 30 mmHg), anterior chamber reformation, decompressive paracentesis, anti-glaucoma medication, and adverse events were recorded. Results: There was a greater decrease in IOP from baseline at days 1, 2, and 21 (p < 0.05) and number of HS at 6 h (p = 0.006) and postoperative day 1 (p < 0.001) in group 2. The mean number of decompressive paracentesis, anterior chamber reformation procedures, and topical anti-glaucoma medications was the same in both groups; the need for oral acetazolamide was significantly lower in group 2 at days 1, 21, and 30 (p < 0.05). Conclusions: While both stenting methods provide a gradual, controlled decrease in IOP, the double stenting technique was associated with a sooner and greater postoperative reduction in IOP and a good safety profile thanks to fewer HS in the early postoperative period and less need for oral acetazolamide
New findings in the diagnosis and treatment of primary angle-closure glaucoma
No full textGlaucoma is the second cause of blindness worldwide. In the next years, approximately one-fourth of all glaucoma cases will be angle-closure types. Older age, female sex, and Asian ethnicities are described risk factors as well as shorter axial length, shallow anterior chamber depth, lens position, and thickness. New findings suggest iris volume and choroidal thickness to have a key role in the mechanisms of angle closure. Classical clinical conditions are acute, intermittent, and chronic forms. Ultrasound biomicroscopy and anterior segment optical coherence tomography contribute to a better understanding of the mechanisms of angle closure, helping the ophthalmologists in the diagnosis and treatment. The therapy includes laser iridotomy, argon laser peripheral iridoplasty, lens extraction, goniosynechialysis, filtering surgery, drainage implant, and cyclodestruction
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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