147 resultados para EYE-MOVEMENTS
Resumo:
A giant retinal tear is a full-thickness retinal break that extends circumferentially around the retina for 90 degrees or more in the presence of a posteriorly detached vitreous. It causes significant visual morbidity from retinal detachment and proliferative vitreoretinopathy. The fellow eye of patients who have had a spontaneous giant retinal tear has an increased risk of developing a giant retinal tear, a retinal detachment or both. Interventions such as 360-degree encircling scleral buckling, 360-degree cryotherapy and 360-degree laser photocoagulation have been advocated by some ophthalmologists as prophylaxis for the fellow eye against the development of a giant retinal tear and/or a retinal detachment, or to prevent its extension. To evaluate the effectiveness of prophylactic 360-degree interventions in the fellow eye of patients with unilateral giant retinal tear to prevent the occurrence of a giant retinal tear, a retinal detachment or both. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 11), MEDLINE (January 1950 to December 2011), EMBASE (January 1980 to December 2011), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to December 2011), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 6 December 2011. In addition, we searched the proceedings of the Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) up to 2008 for information about other relevant studies. Prospective randomised controlled trials (RCTs) comparing one prophylactic treatment for fellow eyes of patients with giant retinal tear against observation (no treatment) or another form of prophylactic treatment. In the absence of RCTs, we planned to discuss case-control studies that met the inclusion criteria but we would not conduct a meta-analysis using these studies. We did not find any studies that met the inclusion criteria for the review and therefore no assessment of methodological quality or meta-analysis could be performed. No studies met the inclusion criteria for this review. No strong evidence in the literature was found to support or refute prophylactic 360-degree treatments to prevent a giant retinal tear or a retinal detachment in the fellow eye of patients with unilateral giant retinal tears.
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Laughter is a frequently occurring social signal and an important part of human non-verbal communication. However it is often overlooked as a serious topic of scientific study. While the lack of research in this area is mostly due to laughter’s non-serious nature, it is also a particularly difficult social signal to produce on demand in a convincing manner; thus making it a difficult topic for study in laboratory settings. In this paper we provide some techniques and guidance for inducing both hilarious laughter and conversational laughter. These techniques were devised with the goal of capturing mo- tion information related to laughter while the person laughing was either standing or seated. Comments on the value of each of the techniques and general guidance as to the importance of atmosphere, environment and social setting are provided.
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The traditional training of surgeons focused exclusively on developing knowledge, clinical expertise, and technical (surgical) skills. However, analyses of the reasons for adverse events in surgery have revealed that many underlying causes originate from behavioural or non-technical aspects of performance (eg, poor communication among members of the surgical team) rather than from a lack of surgical (ie, technical) skills. Therefore, technical skills appear to be necessary but not sufficient to ensure patient safety. Paying attention to non-technical skills, such as team working, leadership, situation awareness, decision making, and communication, will increase the likelihood of maintaining high levels of error-free performance. Identification and training of non-technical skills has been developed for high-risk careers, such as civil aviation and nuclear power. Only recently, training in non-technical skills has been adopted by the surgical world and anaesthetists. Non-technical skills need to be tailored to the environment where they are used, and eye surgery has some substantial differences compared with other surgical areas, for example, high volume of surgery, use of local anaesthetics, and very sophisticated equipment. This review highlights the need for identification of the non-technical skills relevant to eye surgeons and promotion of their use in the training of eye surgeons.
Resumo:
BACKGROUND: In experimental models of retinopathy of prematurity (ROP), a vasoproliferative disorder of the retina, retinal lesions are usually assessed by morphological examination. However, studies suggest that the polyamine system may be useful in monitoring proliferation processes. For this reason, polyamine concentrations in rat erythrocytes (RBC) and the regulation of polyamine system in rat eyes under the conditions relevant to ROP were investigated. METHODS: Newborn Wistar rats were reared in room air (control) or exposed first to hyperoxia (60% or 80% oxygen, 2 weeks) and then to normoxia (relative hypoxia, 1 or 2 weeks). Blood was collected from orbital vessels at 2 weeks of age and before death. Polyamine system-related enzyme activities were measured in retina and lens with radioassays. Polyamines were quantified by fluorometry after extraction, dansylation and HPLC separation. RESULTS: Oxygen (80% only) significantly decreased RBC polyamine concentrations, which then markedly increased after rats were transferred for a week to normal air, suggesting retardation of growth processes and compensatory stimulation, respectively. However, polyamine system changes in the rat eye were not so pronounced. Enzyme activities and polyamine concentrations tended to be lower in retina after hyperoxia and were only slightly higher, with the exception of ornithine decarboxylase, after a subsequent 1 week of normoxia. In litters subjected to normoxia for longer periods no changes were found. CONCLUSION: The transient and short-lived alteration in polyamine metabolism, especially in the eye, suggests that exposure of newborn rats to high oxygen supplementation followed by normoxia does not necessarily result in marked retinopathy.
Resumo:
Plaques constructed with 125I were used to irradiate the sites of perforating ocular injuries in rabbits. An approximate dose of 16Gy given over a period of 6 days was shown to significantly reduce intraocular cellular proliferation when irradiation was commenced within 24 hours after injury. If irradiation was delayed until day 5, this reduction in cellular proliferation and intraocular membrane formation did not occur. Smaller radiation doses of approximately 6Gy given within 24 hours post-injury and administered over 6 days also reduced the extent of cellular proliferation but was not as effective as the 16Gy dose.
Resumo:
Purpose: To evaluate the clinical and histological side effects of a prototype stereotactic radiotherapy system delivering microcollimated external beam radiation through pars plana in porcine eyes.
Methods: Five Yucatan mini-swine (10 eyes) were randomized to five treatment groups. Eight eyes were dosed with X-ray radiation on Day 1, and two eyes served as untreated controls. Treated eyes received doses up to 60 Gy to the retina and up to 130 Gy to the sclera using single or overlapping beams. The treatment beams were highly collimated such that the diameter was approximately 2.5 mm on the sclera and 3 mm on the retinal surface. Fundus photography, fluorescein angiography (FA), and spectral domain optical coherence tomography (SD-OCT) were obtained on days 7, 30, 60, and 110. Images were examined by a masked grader and evaluated for abnormalities. Animals were sacrificed on day 111 and gross and histopathological analysis was conducted.
Results: Histological and gross changes to eye structures including conjunctiva and lens were minimal at all doses. Fundus, FA, and SD-OCT of the targeted region failed to disclose any abnormality in the control or 21 Gy treated animals. In the 42 and 60 Gy animals, hypopigmented spots were noted after treatment on clinical exam, and corresponding hyperfluorescent staining was seen in late frames. No evidence of choroidal hypoperfusion was seen. The histological specimens from the 60 Gy animals showed photoreceptor loss and displacement of cone nuclei.
Conclusion: Transcleral stereotactic radiation dosing in porcine eyes can be accomplished with no significant adverse events as doses less than 42 Gy.
Resumo:
This opportune case study describes visual and stepping behaviours of an 87 year old female (P8), both prior to, and following two falls. Before falling, when asked to walk along a path containing two stepping guides positioned before and after an obstacle, P8 generally visually fixated the first stepping guide until after foot contact inside it. However, after falling P8 consistently looked away from the stepping guide before completing the step into it in order to fixate the upcoming obstacle in her path. The timing of gaze redirection away from the target (in relation to foot contact inside it) correlated with absolute stepping error. No differences in eyesight, cognitive function, or balance were found between pre- and post-fall recordings. However, P8 did report large increases in fall-related anxiety and reduced balance confidence, supporting previously suggested links between anxiety/increased fear or falling and maladaptive visual/stepping behaviours. The results represent a novel insight into how psychological and related behavioural factors can change in older adults following a fall, and provide a possible partial rationalisation for why recent fallers are more likely to fall again in the following 12 months. These findings highlight novel possibilities for falls prevention and rehabilitation.
Resumo:
Transitional justice literature has highlighted a negative relationship between enforced disappearances and reconciliation in post-conflict settings. Little attention has been paid to how human rights issues can become stepping-stones to reconciliation. The article explains the transformation of the Cypriot Committee on Missing Persons (CMP) from an inoperative body into a successful humanitarian forum, paving the way for the pro-rapprochement bi-communal grassroots mobilization of the relatives of the missing. By juxtaposing the experience of Cyprus with other societies confronting similar problems, the article shows how the issue of the missing can become a driving force for reconciliation. The findings indicate that a policy delinking humanitarian exhumations from the prospect of a wider political settlement facilitates positive transformation in protracted human rights problems and opens up a window of opportunity to grassroots actors.
Resumo:
This collection offers a diachronic analytical study of new and alternative social movements in Spain from the democratic transition to the first decade of the 21st century, paying attention to anti-war mobilizations and the use of new technologies as a mobilizing resource. New and alternative social movements are studied through the prism of identified linkages among the left, movement identities and global processes in the Spanish context. Weight is given to certain important historical aspects, like Spain’s relatively recent authoritarian past, and certain value-added factors, such as the weak associationalism and materialism exhibited by the Spanish public. These are complemented by exploring insights offered by key theoretical approaches on social movements (political opportunities structures, resource mobilization). The volume covers established social movement cases (gender, peace, environmental movements) as well as those with a more explicit connection to the current context of global contestation (squatters’ and anti-globalization movements).
Resumo:
Evaluation of: Brown DM, Heier JS, Ciulla T et al. Primary end point results of a Phase II study of vascular endothelial growth factor trap-eye in wet age-related macular degeneration. Ophthalmology 118(6), 1089-1097 (2011); Heier JS, Boyer D, Nguyen QD et al. The 1-year results of CLEAR-IT 2, a Phase 2 study of vascular endothelial growth factor trap-eye dosed as-needed after 12-week fixed dosing. Ophthalmology 118(6), 1098-1106 (2011). Age-related macular degeneration is the most common cause of blindness in older adults in western countries, and is likely to become the largest cause of irreversible sight loss in the developing world. Treatments such as ranibizumab and bevacizumab that inhibit VEGF have improved visual outcomes markedly. Controlled trials and clinical experience have shown that the best outcomes are achieved when monthly treatment has been administered over 2 years. This poses a significant burden on health providers and patients. A novel inhibitor of VEGF, VEGF Trap-Eye, which allows less frequent dosing without loss of efficacy, has emerged as a potential treatment. CLEAR-IT 2 was a prospective randomized Phase II trial designed to assess the safety, tolerability and the anatomic and visual effects of repeated treatments with a range of doses of VEGF Trap-Eye. Impressive anatomic and visual improvements were noted with no safety concerns. © 2011 Expert Reviews Ltd.
Resumo:
Purpose: To describe associations between reticular pseudodrusen, individual characteristics, and retinal function.
Design: Cohort study.
Participants: We recruited 105 patients (age range, 52–93 years) who had advanced neovascular age-related macular degeneration (AMD) in only 1 eye from 3 clinical centers in Europe.
Methods: Minimum follow-up was 12 months. The eye selected for study was the fellow eye without advanced disease. Clinical measures of vision were distance visual acuity, near visual acuity, and results of the Smith-Kettlewell low-luminance acuity test (SKILL). Fundus imaging included color photography, red-free imaging, blue autofluorescence imaging, fluorescein angiography, indocyanine green angiography, and optical coherence tomography using standardized protocols. These were used to detect progression to neovascular AMD in the study eye during follow-up. All imaging outputs were graded for the presence or absence of reticular pseudodrusen (RPD) using a multimodal approach. Choroidal thickness was measured at the foveal center and at 2 other equidistant locations from the fovea (1500 μm) nasally and temporally. Metrics on retinal thickness and volume were obtained from the manufacturer-supplied automated segmentation readouts.
Main Outcome Measures: Presence of RPD, distance visual acuity, near visual acuity, SKILL score, choroidal thickness, retinal thickness, and retinal volume.
Results: Reticular pseudodrusen was found in 43 participants (41%) on 1 or more imaging method. The SKILL score was significantly worse in those with reticular drusen (mean score ± standard deviation [SD, 38±12) versus those without (mean score ± SD, 33±9) (P = 0.034). Parafoveal retinal thickness, parafoveal retinal volume, and all of the choroidal thickness parameters measured were significantly lower in those with reticular drusen than in those without. The presence of RPD was associated with development of neovascular AMD when corrected for age and sex (odds ratio, 5.5; 95% confidence interval, 1.1–28.8; P = 0.042). All participants in whom geographic atrophy developed during follow-up had visible RPD at baseline.
Conclusions: Significant differences in retinal and choroidal anatomic features, visual function, and risk factor profile exist in unilateral neovascular AMD patients with RPD compared with those without; therefore, such patients should be monitored carefully because of the risk of developing bilateral disease.