785 resultados para Multifocal intraocular lens


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The mathematical representation of Brunswik s lens model has been usedextensively to study human judgment and provides a unique opportunity to conduct ameta-analysis of studies that covers roughly five decades. Specifically, we analyzestatistics of the lens model equation (Tucker, 1964) associated with 259 different taskenvironments obtained from 78 papers. In short, we find on average fairly high levelsof judgmental achievement and note that people can achieve similar levels of cognitiveperformance in both noisy and predictable environments. Although overall performancevaries little between laboratory and field studies, both differ in terms of components ofperformance and types of environments (numbers of cues and redundancy). An analysisof learning studies reveals that the most effective form of feedback is information aboutthe task. We also analyze empirically when bootstrapping is more likely to occur. Weconclude by indicating shortcomings of the kinds of studies conducted to date, limitationsin the lens model methodology, and possibilities for future research.

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INTRODUCTION: The association of a granulomatous uveitis and congenital cataract and is rarely observed in newborn children. We describe the history of two patients presenting simultaneously with these two features in the absence of a TORCH infection. PATIENTS AND METHODS: The first patient, a boy born in 1997, presented to our hospital two days after birth with multiples Koeppe's and Busacca's nodules and bilateral cataract. The second patient, a boy born in 2006, was referred two weeks after birth. He presented with a severe unilateral granulomatous uveitis, multiples iris nodules, a high intraocular pressure of 45 mmHg and a congenital cataract. THERAPY AND OUTCOME: Lens extraction produced a rapid resolution of uveitis in these two patients. TORCH infection was ruled out in both children by history, extensive serologies performed simultaneously in mother and child or PCR of ocular fluids. CONCLUSIONS: A congenital cataract associated with a granulomatous uveitis is an extremely rare association. The removal of the lens resulted in complete resolution of the inflammation: a phacogenic mechanism could be at the origin of ocular inflammation in both cases.

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Epithelioid hemangioendothelioma is a rare, low-grade vascular malignancy reported for the first time in 1982 by Weiss and Enzinger. It involves one or, more rarely, several organs. We report a case involving the lungs and liver, in which the first manifestation was symptomatic hypertrophic osteoarthropathy. Findings four years after the diagnosis included very slow tumor spread, resolution of symptoms, and stabilization of radiological changes.

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Purpose: to describe a case in which the diagnosis of Morganian cataract required clinical and instrumental differentiation from iris pathologies, including iris melanoma. Methods: a 60-years-old Caucasian man referred to our institute for worsening of vision in last few months. Clinical evaluation consisted in complete ophthalmological assessment, ultrasound examination (biomicroscopy and 20MHz), and Magnetic Resonance Imaging (MRI) completed with Susceptibility Weighted Imaging (SWI). Results: traumatic corneal wound of the left eye (LE) had occurred 5 years before, and was treated with medical therapy alone. Best-corrected visual acuity (BCVA) was 3/10 in the right eye (RE) and finger count in the LE, with intraocular pressure at 13 and 20mmHg, respectively. Chronic central serous chorioretinopathy, accounted for the low visual acuity of the RE. Slit-lamp biomicroscopy of the LE was as in Figure 1; LE fundus was not clinically observable. Despite MRI was compatible with an iris solid formation, characterized by contrast enhancement and hyperintense signal in SWI, ultrasound indicated rather a mixed solid and liquid content (moderately echogenic external layer, hyporeflective internal content). Iris root and ciliary body were not significantly altered; the lens showed inhomogeneous content. We considered Morgagnian cataract the most probable diagnosis. Surgery confirmed the presence of a hypermature cataract with prior anterior capsule fissuring; the liquefied cortex infiltrated the iris without anterior chamber seeping. Post-operative BCVA was 3/10 and fundus examination disclosed an advanced macular chronic central serous chorioretinopathy. Conclusions: In the reported case a previous perforating trauma have probably damaged the lens capsule and started cataract progression. Curiously cataract developed percolating into the iris stroma, thus simulating an iris mass. At our knowledge, Morgagnian cataract has never been included in the differential diagnosis of iris mass.

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PURPOSE: To evaluate the effect of intraocular administration of nitric oxide (NO) donors in the rabbit eye on intraocular pressure (IOP), inflammation, and toxicity. METHODS: Intravitreal and intracameral injections of two NO donors, SIN-1 and SNAP, and SIN-1C and BSS were performed. Clinical examination, IOP measurements, protein evaluation in aqueous humor, and histologic analysis of the ocular globes were realized. Nitric oxide release was demonstrated by nitrite production in the aqueous humor and in the vitreous using the Griess reaction. RESULTS: The drastic decrease of IOP, observed after a single NO donor injection, was correlated directly with nitrite production and, thus, to NO release. Injection of inactive metabolite of SIN-1, SIN-1C, which is not able to release NO, did not modulate IOP. When administered in the aqueous humor or in the vitreous, NO did not diffuse from one segment of the eye to another. No inflammation or histologic damage was observed as a result of a single NO donor administration. CONCLUSIONS: Nitric oxide is implicated directly in the regulation of IOP and its acute, and massive release into the rabbit eye did not induce inflammation or other growth toxic effects on the ocular tissues.

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BACKGROUND: : Superselective ophthalmic artery chemotherapy (SOAC) has recently been proposed as an alternative to intravenous chemoreduction for advanced intraocular retinoblastoma. Preliminary results appear promising in terms of tumor control and eye conservation, but little is known regarding ocular toxicity and visual prognosis. In this study, we report on the vascular adverse effects observed in our initial cohort of 13 patients. METHODS: : The charts of 13 consecutive patients with retinoblastoma who received a total of 30 injections (up to 3 injections of a single agent per patient at 3-week interval) of melphalan (0.35 mg/kg) in the ophthalmic artery between November 2008 and June 2010 were retrospectively reviewed. RetCam fundus photography and fluorescein angiography were performed at presentation and before each injection. Vision was assessed at the latest visit. RESULTS: : Enucleation and external beam radiotherapy could be avoided in all cases but one, with a mean follow-up of 7 months. Sectoral choroidal occlusive vasculopathy leading to chorioretinal atrophy was observed temporally in 2 eyes (15%) 3 weeks to 6 weeks after the beginning of SOAC and retinal arteriolar emboli in 1 eye 2 weeks after injection. There was no stroke or other clinically significant systemic side effects except a perioperative transient spasm of the internal carotid artery in one patient. Vision ranged between 20/1600 and 20/32 depending on the status of the macula. CONCLUSION: : Superselective ophthalmic artery chemotherapy was effective in all patients with no stroke or other systemic vascular complications. Unlike intravenous chemoreduction, SOAC is associated with potentially sight-threatening adverse effects, such as severe chorioretinal atrophy secondary to subacute choroidal occlusive vasculopathy or central retinal artery embolism, not to mention the risk of ophthalmic artery obstruction, which was not observed in this series. Further analysis of the risks and benefits of SOAC will define its role within the therapeutic arsenal. Meanwhile, we suggest that SOAC should be given in one eye only and restricted to advanced cases of retinoblastoma, as an alternative to enucleation and/or external beam radiotherapy.

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Abstract Purpose: We aimed to investigate the safety, tolerability, and systemic diffusion of a single escalating dose of XG-102 (a 31-D-amino-acid peptide inhibiting JNK pathway activation), administered subconjunctivally in the treatment of post-surgery or post-trauma intraocular inflammation. Methods: This is a dose-escalating, tolerance Phase Ib study. Twenty patients with post-surgery or post-traumatic intraocular inflammation were assigned to 1 of the 4 dose escalating (45, 90, 450, or 900 μg XG-102) groups of 5 patients each. Patients were evaluated at 24, 48 h, 8, and 28 days following the administration of XG-102, including laboratory tests, standard eye examinations, vital signs, and occurrence of adverse events. A single plasma quantification of XG-102 was performed 30 min after administration, according to previous pharmacokinetics studies performed on volunteers. Results: A total of 17 non-serious adverse events, considered unrelated to the study treatment, were reported for 10 patients. The adverse event incidence was not related to the drug dose. All patients experienced a decrease in intraocular inflammation as of 24 h post-administration and this decrease was sustained up to 28 days thereafter. No patient required local injection or systemic administration of corticoids following the administration of XG-102. XG-102 was undetectable in the first 3 dose groups. In the fourth-dose group (900 μg) the XG-102 plasma levels were above the limit of detection for 3 patients and above the limit of quantification for 1 patient. Conclusions: In this first clinical trial using XG-102, administered as a single subconjunctival injection as adjunct therapy, in patients with recent post-surgery or post-trauma intraocular inflammation is safe and well tolerated. Further studies are required to evaluate its efficacy.

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PURPOSE: To evaluate the safety and efficacy of an intravitreal fluocinolone acetonide (FA) implant compared with standard therapy in subjects with noninfectious posterior uveitis (NIPU). DESIGN: Randomized, controlled, phase 2b/3, open-label, multicenter superiority trial. PARTICIPANTS: Subjects with unilateral or bilateral NIPU. METHODS: One hundred forty subjects received either a 0.59-mg FA intravitreal implant (n = 66) or standard of care (SOC; n = 74) with either systemic prednisolone or equivalent corticosteroid as monotherapy (> or =0.2 mg/kg daily) or, if judged necessary by the investigator, combination therapy with an immunosuppressive agent plus a lower dose of prednisolone or equivalent corticosteroid (> or =0.1 mg/kg daily). MAIN OUTCOME MEASURES: Time to first recurrence of uveitis. RESULTS: Eyes that received the FA intravitreal implant experienced delayed onset of observed recurrence of uveitis (P<0.01) and a lower rate of recurrence of uveitis (18.2% vs. 63.5%; P< or =0.01) compared with SOC study eyes. Adverse events frequently observed in implanted eyes included elevated intraocular pressure (IOP) requiring IOP-lowering surgery (occurring in 21.2% of implanted eyes) and cataracts requiring extraction (occurring in 87.8% of phakic implanted eyes). No treatment-related nonocular adverse events were observed in the implant group, whereas such events occurred in 25.7% of subjects in the SOC group. CONCLUSIONS: The FA intravitreal implant provided better control of inflammation in patients with uveitis compared with systemic therapy. Intraocular pressure and lens clarity of implanted eyes need close monitoring in patients receiving the FA intravitreal implant.

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The main aim of the Work Package 1 (WP1) of the ORAMED project, Collaborative Project (2008-2011), supported by the European Commission within its 7th Framework Programme, was to obtain a set of standardized data on extremity and eye lens doses for staff in interventional radiology and cardiology (IR/IC) workplaces and to recommend a series of guidelines on radiation protection in order to both guarantee and optimize staff protection. Within the project, coordinated measurements were performed in 34 hospitals in 6 European countries. Furthermore, simulations of the most representative workplaces in IR and IC were performed to determine the main parameters that influence the extremity and eye lens doses. The work presented in this paper shows the recommendations that were formulated by the results obtained from both measurements and simulations. The presented guidelines are directed to operators, assistant personnel, radiation protection officers and medical physics experts. They concern radiation protection issues, such as the use of room protective equipment, as well as the positioning of the extremity and eye lens dosemeters for routine monitoring.

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A computer-aided method to improve the thickness uniformity attainable when coating multiple substrates inside a thermal evaporation physical vapor deposition unit is presented. The study is developed for the classical spherical (dome-shaped) calotte and also for a plane sector reversible holder setup. This second arrangement is very useful for coating both sides of the substrate, such as antireflection multilayers on lenses. The design of static correcting shutters for both kinds of configurations is also discussed. Some results of using the method are presented as an illustration.

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PURPOSE: Ocular anatomy and radiation-associated toxicities provide unique challenges for external beam radiation therapy. For treatment planning, precise modeling of organs at risk and tumor volume are crucial. Development of a precise eye model and automatic adaptation of this model to patients' anatomy remain problematic because of organ shape variability. This work introduces the application of a 3-dimensional (3D) statistical shape model as a novel method for precise eye modeling for external beam radiation therapy of intraocular tumors. METHODS AND MATERIALS: Manual and automatic segmentations were compared for 17 patients, based on head computed tomography (CT) volume scans. A 3D statistical shape model of the cornea, lens, and sclera as well as of the optic disc position was developed. Furthermore, an active shape model was built to enable automatic fitting of the eye model to CT slice stacks. Cross-validation was performed based on leave-one-out tests for all training shapes by measuring dice coefficients and mean segmentation errors between automatic segmentation and manual segmentation by an expert. RESULTS: Cross-validation revealed a dice similarity of 95% ± 2% for the sclera and cornea and 91% ± 2% for the lens. Overall, mean segmentation error was found to be 0.3 ± 0.1 mm. Average segmentation time was 14 ± 2 s on a standard personal computer. CONCLUSIONS: Our results show that the solution presented outperforms state-of-the-art methods in terms of accuracy, reliability, and robustness. Moreover, the eye model shape as well as its variability is learned from a training set rather than by making shape assumptions (eg, as with the spherical or elliptical model). Therefore, the model appears to be capable of modeling nonspherically and nonelliptically shaped eyes.