1,605 research outputs found
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Improving Visual Field Examination of the Macula Using Structural Information
Purpose: To investigate a novel approach for structure-function modeling in glaucoma to improve visual field testing in the macula.
Methods: We acquired data from the macular region in 20 healthy eyes and 31 with central glaucomatous damage. Optical coherence tomography (OCT) scans were used to estimate the local macular ganglion cell density. Perimetry was performed with a fundus-tracking device using a 10-2 grid. OCT scans were matched to the retinal image from the fundus perimeter to accurately map the tested locations onto the structural damage. Binary responses from the subjects to all presented stimuli were used to calculate the structure-function model used to generate prior distributions for a ZEST (Zippy Estimation by Sequential Testing) Bayesian strategy. We used simulations based on structural and functional data acquired from an independent dataset of 20 glaucoma patients to compare the performance of this new strategy, structural macular ZEST (MacS-ZEST), with a standard ZEST.
Results: Compared to the standard ZEST, MacS-ZEST reduced the number of presentations by 13% in reliable simulated subjects and 14% with higher rates (≥20%) of false positive or false negative errors. Reduction in mean absolute error was not present for reliable subjects but was gradually more important with unreliable responses (≥10% at 30% error rate).
Conclusions: Binary responses can be modeled to incorporate detailed structural information from macular OCT into visual field testing, improving overall speed and accuracy in poor responders.
Translational Relevance: Structural information can improve speed and reliability for macular testing in glaucoma practice
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Optical Coherence Tomography Angiography of Iris Nevus: A Case Report
Iris nevus is common: 6% of patients with suspected iris melanoma have lesions other than melanoma, and 36% of them are nevi. Iris nevus turns into melanoma in approximately 8% of cases at a mean of 15 years. This case report provides the first description of an iris tumor examined with iris optical coherence tomography angiography (OCTA) compared to iris fluorescein angiography (IFA). A 60-year-old man with a diagnosis of iris nevus in the left eye was referred to our department for IFA and iris OCTA. The iris vasculature in IFA was visible only in the early phases, but not clearly. OCTA, however, gave visualization of the vascular network and very precisely defined the vessels of the whole lesion, except for the pupillary portion, which was masked by superficial pigment accumulations. IFA and iris OCTA can add information about the vascular architecture compared to slit-lamp biomicroscopy, ultrasound biomicroscopy, and anterior-segment OCT. However, IFA is time-consuming and invasive and can – very occasionally – cause serious adverse reactions. In contrast, OCTA defines the texture of the iris vasculature better. In conclusion, OCTA is a new method, easy to execute, needing no dye injection, and provides useful information on the vascular network of iris lesions. It could therefore be helpful in the diagnosis and follow-up of these lesions
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Testing a phantom eye under various signal-to-noise ratio conditions using eleven different OCT devices
We compared eleven OCT devices in their ability to quantify retinal layer thicknesses under different signal-strength conditions, using a commercially available phantom eye. We analyzed a medium-intensity 50 µm layer in an identical manner for all devices, using the provided log-scale images and a reconstructed linear-scale tissue reflectivity metric. Thickness measurements were highly comparable when the data were analyzed in an identical manner. With optimal signal strength, the thickness of the 50 µm layer was overestimated by a mean of 4.3 µm in the log-scale images and of 2.7 µm in the linear-scale images
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Effect of prophylactic timolol 0.1% gel on intraocular pressure after an intravitreal injection of ranibizumab: a randomized study
Purpose: The purpose of this study is to make a prospective evaluation of the effect of timolol 0.1% eye gel on short-term intraocular pressure (IOP) after an intravitreal injection (IVI) of ranibizumab.
Participants and methods: One hundred and fifty eyes of 150 IVI-naĂŻve patients with macular edema caused by various pathological conditions (age-related macular degeneration, central or branch retinal vein occlusion, and diabetic retinopathy) were scheduled to undergo an IVI of ranibizumab (0.5 mg/0.05 cc). The patients were randomly divided into three groups: 50 were not treated with timolol before the IVI (group 1); 50 received an instillation of timolol 0.1% eye gel the evening before the IVI (group 2); and 50 received an instillation of timolol 0.1% eye gel 2 hours before the IVI (group 3). The incidence of clinically significant intraocular hypertensive spikes (>25 mmHg and >40 mmHg) was then assessed.
Results: Our findings showed that mean IOP at baseline was significantly higher than at both 5 and 60 minutes after IVI (P25 mmHg were recorded at either time in 27 patients (54%) in group 1, 23 patients (44%) in group 2, and 24 patients (48%) in group 3. None of the between-group differences were significant. Spikes of >40 mmHg (which were only detected 5 minutes after IVI) were recorded in nine (18%), eight (16%), and one patient (2%) in groups 1, 2, and 3, respectively. The only significant difference was between the control and group 3 (P=0.012).
Conclusion: An increase in IOP after antivascular endothelial growth factor IVI is a frequent complication. The prophylactic use of timolol 0.1% gel effectively reduced the mean IOP when administered 2 hours before IVI and was also effective in preventing dangerous IOP spikes of >40 mmHg. It is therefore recommended before IVIs as a means of preventing emergency procedures and preserving the health of the optic nerve
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Improving perimetric examination of the macular visual field using structural information
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Cataract and optic disk drusen in a patient with glycogenosis and di George syndrome: clinical and molecular report
Background
We report the ophthalmic findings of a patient with type Ia glycogen storage disease (GSD Ia), DiGeorge syndrome (DGS), cataract and optic nerve head drusen (ONHD).
Case presentation
A 26-year-old white woman, born at term by natural delivery presented with a post-natal diagnosis of GSD Ia. Genetic testing by array-comparative genomic hybridization (CGH) for DGS was required because of her low levels of serum calcium. The patient has been followed from birth, attending the day-hospital every six months at the San Paolo Hospital, Milan, outpatient clinic for metabolic diseases and previously at another eye center. During the last day-hospital visit, a complete eye examination showed ONHD and cataract in both eyes. Next Generation Sequencing (NGS) was subsequently done to check for any association between the eye problems and metabolic aspects.
Conclusions
This is the first description of ocular changes in a patient with GSD Ia and DGS. Mutations explaining GSD Ia and DGS were found but no specific causative mutation for cataract and ONHD. The metabolic etiology of her lens changes is known, whereas the pathogenesis of ONHD is not clear. Although the presence of cataract and ONHD could be a coincidence; the case reported could suggest that hypocalcemia due to DGS could be the common biochemical pathway
Synthesis by sol-gel technique and Antibacterial activity of bioactive hydrid SiO2 inorganic matrix by different structures of Ferrous citrate (Fe(II)C): comparative study
Abstract.
The aim of this work was to characterize and compare three different structures of Ferrous citrate (Fe(II)C), amorphous, semi-crystalline and crystalline incorporated into a SiO2 inorganic matrix by sol-gel technique. On this system thus obtained, colorimetric assay was carried out to confirm the only presence of Fe2+; Fourier transform infrared spectroscopy (FTIR) confirmed not only the Fe(II)C presence in the silica matrix but also showed us the interactions among different components in the hybrid materials. The bioactivity of the synthesized hybrid materials was evaluated by the formation of a layer of hydroxyapatite on the surface of samples soaked in SBF using FTIR spectroscopy. Finally, the antibacterial properties of the hybrid materials were investigated
Waste recovery and circular economy: a resource from orange peels deriving from production of orange juice
In the perspective of bio-sustainable development and renewable resource technologies, by-products
and waste from agro-industrial sector represent a relatively cheap source of material suitable for
several aims, which would reduce both the amount of waste and the related costs of disposal, while
producing added-value nutritional products.
The processing waste of oranges find various fields of application, in fact in addition to their use in
agriculture as a fertilizer, orange peels can be used to produce candied fruit. Moreover, in a very
recent application with the aim to recover these industrial residues, a chemical process that allows
the processing of orange peel waste has been developed. This process is useful for obtaining a purified
cellulose suitable for spinning, thus creating a truly innovative and sustainable fabric (Orange Fiber).
In this work, the orange peels obtained from industrial processing waste were subjected to a first
hydroalcoholic extraction which allowed to obtain an extract rich in essential oils that could be used
in the food sector to produce liqueurs and/or aromas, but also in the cosmetic or pharmacological
sectors.
Subsequently, the peels after hydroalcoholic extraction were dried and this residue represents a
valuable product rich in dietetic fiber useful in nutraceutical and pharmaceutical fields. Moreover,
the same product could be used as fertilizer in agriculture. In lights of this, citrus fruit processing
waste can be considerate as a sustainable and renewable energy source
Various applications of processing of olive leaves waste extracted with RSLDE: a green technology
There is no waste in nature. Everything that is produced has a purpose and everything that becomes
waste can be transformed into a new resource, triggering a virtuous circuit that feeds itself. The
circular economy of waste means a system in which the production-consumption-disposal process is
overcome to replace it with a circular model, where the final waste product is re-introduced into the
circulation as a secondary raw material. The logic to follow is that after consumption and before any
disposal, it is necessary to activate virtuous processes such as reduce, reuse and recycling. This work
focuses on the possible uses of a vegetable waste matrix, such as olive leaves.
The olive tree (Olea europaea) is a fruit tree, cultivated for more than 3,500 years for its fruits and
edible oil. However, just like oil, olive leaf contains a high amount of polyphenols, in particular
oleuropein, one of the most powerful natural antioxidants known and hydroxytyrosol, which also has
powerful antiseptic properties. Therefore, olive leaf extracts, thanks to the presence of oleuropein
associated with hydroxytyrosol, represent a powerful natural antioxidant, a valid ally of the
cardiovascular system. In addition, olive leaves are an excellent regulator of the digestive system:
they regulate intestinal transit and above all eliminate fungi and other unwanted parasites from our
body. Starting from these premises, in this work, a green extraction technique such as rapid solid
liquid dynamic extraction (RSLDE) is compared with conventional maceration to obtain an olive leaf
extract rich in antioxidants to be used in various sectors
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