Search results for "Eye"

Reazioni consecutive di Pschorr e Sandmeyer non classiche in serie pirazolo-tiofenica. Accesso a composti di interesse farmaceutico

2010

Antagonistic feedback loops involving Rau and Sprouty in the Drosophila eye control neuronal and glial differentiation.

2013

During development, differentiation is often initiated by the activation of different receptor tyrosine kinases (RTKs), which results in the tightly regulated activation of cytoplasmic signaling cascades. In the differentiation of neurons and glia in the developing Drosophila eye, we found that the proper intensity of RTK signaling downstream of fibroblast growth factor receptor (FGFR) or epidermal growth factor receptor required two mutually antagonistic feedback loops. We identified a positive feedback loop mediated by the Ras association (RA) domain-containing protein Rau that sustained Ras activity and counteracted the negative feedback loop mediated by Sprouty. Rau has two RA domains t…

Non-Classical Transformation of Benzendiazonium Hydrogen Sulfates. Access to 1,3-Dimethylisochromeno[4,3-c]pyrazol-5(1H)-one, a Potential Benzodiazep…

2013

The compound 2-((1,3-dimethyl-1H-pyrazol-5-yl)(methyl)carbamoyl)benzene-diazonium hydrogen sulfate (10) was reacted with copper sulfate and sodium chloride, in the presence of ascorbic acid as reducing agent, to afford a mixture of the chlorinated epimers 4′-chloro-2,2′,5′-trimethyl-2′,4′-dihydrospiro[isoindoline-1,3′-pyrazol]-3-one (18) and (19), the epimers 4′-hydroxy-2,2′,5′-trimethyl-2′,4′-dihydrospiro[isoindoline-1,3′-pyrazol]-3-one (20) and (21), and N-(1,3-dimethyl-1H-pyrazol-5-yl)benzamide (22). Under the foregoing conditions, diazonium salt 10 affords neither the 2-chloro-N-(1,3-dimethyl-1H-pyrazol-5-yl)-N-methylbenzamide (23) nor the tricyclic derivative 24, the classical products…

Genetic variants linked to myopic macular degeneration in persons with high myopia: CREAM Consortium.

2019

Purpose: To evaluate the roles of known myopia-associated genetic variants for development of myopic macular degeneration (MMD) in individuals with high myopia (HM), using case-control studies from the Consortium of Refractive Error and Myopia (CREAM). Methods: A candidate gene approach tested 50 myopia-associated loci for association with HM and MMD, using meta-analyses of case-control studies comprising subjects of European and Asian ancestry aged 30 to 80 years from 10 studies. Fifty loci with the strongest associations with myopia were chosen from a previous published GWAS study. Highly myopic (spherical equivalent [SE] ≤ -5.0 diopters [D]) cases with MMD (N = 348), and two sets of cont…

The effect of fractal contact lenses on peripheral refraction in myopic model eyes.

2014

Purpose: To test multizone contact lenses in model eyes: Fractal Contact Lenses (FCLs), designed to induce myopic peripheral refractive error (PRE). Methods: Zemax ray-tracing software was employed to simulate myopic and accommodation-dependent model eyes fitted with FCLs. PRE, defined in terms of mean sphere M and 90–180 astigmatism J180, was computed at different peripheral positions, ranging from 0 to 35 in steps of 5, and for different pupil diameters (PDs). Simulated visual performance and changes in the PRE were also analyzed for contact lens decentration and model eye accommodation. For comparison purposes, the same simulations were performed with another commercially available conta…

The stenopaeic slit: an analytical expression to quantify its optical effects in front of an astigmatic eye.

2001

The stenopaeic slit is a trial case accessory used in subjective refraction, especially when high astigmatism is present. In spite of its simplicity, the effect of the slit when it is not oriented along one of the principal meridians of the examined eye is difficult to predict, even in terms of classical geometrical optics. In this paper, the optical principles of the slit are considered with full details in the theoretical framework of the dioptric power space. An analytical expression to obtain the residual refractive error when a stenopaeic slit is placed in front of an astigmatic eye at any orientation is deduced. In the light of these results, some aspects of the clinical procedure are…

Phake Intraokularlinsen

2004

Phakic intraocular lenses (PIOLs), which are located closer to the eye's nodal points than the anterior corneal surface, can provide superior optical quality for higher corrections because of retention of normal prolate corneal asphericity and larger effective optical zones. Improvements in the material and design of phakic intraocular lenses and their insertion devices combined with advances in the understanding of the anatomical and physiological interactions of the PIOLs with intraocular structures, have increased safety and efficacy. Safety of these implants over the long term remains a concern, but in several situations PIOLs are the refractive correction of choice. The purpose of this…

Short-Term Changes in Light Distortion in Orthokeratology Subjects

2015

Purpose. Quantifying adaptation to light distortion of subjects undergoing orthokeratology (OK) for myopia during the first month of treatment. Methods. Twenty-nine healthy volunteers (age: 22.34 ± 8.08 years) with mean spherical equivalent refractive error −2.10 ± 0.93D were evaluated at baseline and days 1, 7, 15, and 30 of OK treatment. Light distortion was determined using an experimental prototype. Corneal aberrations were derived from corneal topography for different pupil sizes. Contrast sensitivity function (CSF) was analyzed for frequencies of 1.50, 2.12, 3.00, 4.24, 6.00, 8.49, 12.00, 16.97, and 24.00 cpd under photopic conditions. Results. Average monocular values of all light di…

Trifocal toric intraocular lenses in eyes with low amount of corneal astigmatism.

2020

Aim To evaluate the refractive and visual outcomes following cataract surgery and implantation of a trifocal toric intraocular lens (IOL) in eyes with low degrees of corneal astigmatism. Methods Twenty-six eyes of 22 patients who underwent implantation a trifocal toric IOL (FineVision PODFT, PhysIOL s.a., Liege, Belgium) were enrolled. Phacoemulsification with femtosecond laser, capsular tension ring insertion and intraoperative aberrometry were performed in all cases. All IOLs used showed a cylinder power of 1.00 D. Main outcome measures were refractive error and corrected-distance visual acuity (CDVA) and uncorrected-distance visual acuity (UDVA) values. Eyes were evaluated at 4mo post-su…

Contrast sensitivity after refractive lens exchange with diffractive multifocal intraocular lens implantation in hyperopic eyes

2008

Contrast Test chart at distance and near under 3 luminance levels (85.0 cd/m 2 , 5.0 cd/m 2 , and 2.5 cd/m 2 ) before and after RLE with bilateral AcrySof ReSTOR IOL implantation in 30 hyperopic eyes with presbyopia and low astigmatism (%1.0 diopter). Results after surgery were compared with those before surgery. RESULTS: Six months postoperatively, the mean residual spherical equivalent refractive error was 0.21 diopter G 0.19 (SD). The best corrected distance and near visual acuities were comparable to those before surgery. For distance vision, the safety index was 1.02 and the efficacy index was 0.91. For near vision, the values were 1.04 and 1.02, respectively. There were no statistical…