3 literature review
... hypothesis that important vascular phenomena are associated with small increases in short or long-term air pollution exposures, even at current exposure levels, and further corroborate reported associations between air pollution and the development and exacerbation of clinical cardiovascular disease ...
... hypothesis that important vascular phenomena are associated with small increases in short or long-term air pollution exposures, even at current exposure levels, and further corroborate reported associations between air pollution and the development and exacerbation of clinical cardiovascular disease ...
Neonatal Eye Defects and Stem Cell Therapeutics Introduction
... factors involved in eye formation. Hmx1 is a homeodomain transcription factor that is expressed in the developing eye mainly in peripheral ganglia, and branchial arches of avian and mammalian embryos. Different expression patterns of transcription factors and biological signaling are essential step ...
... factors involved in eye formation. Hmx1 is a homeodomain transcription factor that is expressed in the developing eye mainly in peripheral ganglia, and branchial arches of avian and mammalian embryos. Different expression patterns of transcription factors and biological signaling are essential step ...
spatial disorientation
... The retina, an evaginated portion of the embryonic brain, consists of an outer layer of pigmented epithelium and an inner layer of neural tissue. Contained within the latter layer are the sensory rod and cone cells, the bipolar and horizontal cells that comprise the intraretinal afferent pathway fro ...
... The retina, an evaginated portion of the embryonic brain, consists of an outer layer of pigmented epithelium and an inner layer of neural tissue. Contained within the latter layer are the sensory rod and cone cells, the bipolar and horizontal cells that comprise the intraretinal afferent pathway fro ...
A Guide to the Use of Diagnostic Instruments in Eye and Ear
... slightly to the right (25º) of the patient and direct the light beam into the pupil. A red “reflex” should appear as you look through the pupil. 6. Rest your left hand on the patient’s forehead and hold the upper lid of the eye near the eyelashes with the thumb. While the patient is fixating on the ...
... slightly to the right (25º) of the patient and direct the light beam into the pupil. A red “reflex” should appear as you look through the pupil. 6. Rest your left hand on the patient’s forehead and hold the upper lid of the eye near the eyelashes with the thumb. While the patient is fixating on the ...
Macular Thickness Measurements in Normal Eyes Using Spectral
... data in HD-OCT images leads to more accurate and detailed macular thickness maps. The ability to center the measurements accurately on the true fovea should reduce the v ...
... data in HD-OCT images leads to more accurate and detailed macular thickness maps. The ability to center the measurements accurately on the true fovea should reduce the v ...
Autofluorescence from the Outer Retina and Subretinal Space
... loculated fluid space with no means of escape for the shed photoreceptor outer segments (Fig. 17.9). Accumulation of the photoreceptor outer segments, admixed with possible lipoproteins from the serous fluid leaking into the subretinal space, may lead to the buildup of the autofluorescent material s ...
... loculated fluid space with no means of escape for the shed photoreceptor outer segments (Fig. 17.9). Accumulation of the photoreceptor outer segments, admixed with possible lipoproteins from the serous fluid leaking into the subretinal space, may lead to the buildup of the autofluorescent material s ...
CHILDREN WITH CORTICAL VISION IMPAIRMENT: IMPLICATIONS
... the visual cortex, some of which deal with colour, some with motion and others with shape or a combination of all three. She suggests that information is exchanged between these areas and also the primary visual cortex and that damage to any of them can result in cortical vision impairment. In addit ...
... the visual cortex, some of which deal with colour, some with motion and others with shape or a combination of all three. She suggests that information is exchanged between these areas and also the primary visual cortex and that damage to any of them can result in cortical vision impairment. In addit ...
High fluence CXL and Corneal Limbus
... applied include Terrien’s marginal degeneration, and rosacea mediated or trophic peripheral ulcers. In these cases, a decentered irradiation also was performed to cover the area of active disease.20,21 No limbal stem cell deficiency was reported by the authors. The corneal epithelium shows a physiol ...
... applied include Terrien’s marginal degeneration, and rosacea mediated or trophic peripheral ulcers. In these cases, a decentered irradiation also was performed to cover the area of active disease.20,21 No limbal stem cell deficiency was reported by the authors. The corneal epithelium shows a physiol ...
Land (1992) The evolution of eyes - Mark Wexler
... about the distribution of light and dark in the surroundings. However, with only shadowingfrom the pigment cup to restrict the acceptance angle of individual receptors, the resolution is muchtoo poor for the eye to detect predators or prey, or to be involved in pattern recognition or the control of ...
... about the distribution of light and dark in the surroundings. However, with only shadowingfrom the pigment cup to restrict the acceptance angle of individual receptors, the resolution is muchtoo poor for the eye to detect predators or prey, or to be involved in pattern recognition or the control of ...
Optical Lenses and Devices
... Eyes are our visual window to the world. They are complex structures that are capable of very high resolution, are extremely sensitive to light, capable even of detecting single photons, can give color and depth perception, and adjust to focus on objects from as close as 10 cm, in young eyes, to “in ...
... Eyes are our visual window to the world. They are complex structures that are capable of very high resolution, are extremely sensitive to light, capable even of detecting single photons, can give color and depth perception, and adjust to focus on objects from as close as 10 cm, in young eyes, to “in ...
Management of Pseudophakic Retinal Detachment
... Hospital, Malir Karachi from 1st January to December 2005. Study include 23 pseudophakic eyes of 23 patients with pseudophakic retinal detachment, who underwent three ports pars plana vitrectomy with silicone oil tamponade and endolaser. Postoperatively 3 months follow up was carried out. Results: 2 ...
... Hospital, Malir Karachi from 1st January to December 2005. Study include 23 pseudophakic eyes of 23 patients with pseudophakic retinal detachment, who underwent three ports pars plana vitrectomy with silicone oil tamponade and endolaser. Postoperatively 3 months follow up was carried out. Results: 2 ...
Visual Response Properties of Neurons in the LGN of Normally
... contrast gain control mechanism). We found little evidence for major differences between magno- and parvocellular neurons on the basis of most spatial parameters except that at any eccentricity, the neurons with the smallest receptive field centers tended to be parvocellular. All parameters were dis ...
... contrast gain control mechanism). We found little evidence for major differences between magno- and parvocellular neurons on the basis of most spatial parameters except that at any eccentricity, the neurons with the smallest receptive field centers tended to be parvocellular. All parameters were dis ...
Exceptional Variation on a Common Theme: The Evolution of
... reduce the visibility of these otherwise transparent plankton. A more profound modification is to collapse the retina into a tiny blob of pigmented receptors and lead light from the very distant corneal facets to it via biological fiber optics. This can produce an eye with excellent visual acuity an ...
... reduce the visibility of these otherwise transparent plankton. A more profound modification is to collapse the retina into a tiny blob of pigmented receptors and lead light from the very distant corneal facets to it via biological fiber optics. This can produce an eye with excellent visual acuity an ...
Cronin - USD Biology
... reduce the visibility of these otherwise transparent plankton. A more profound modification is to collapse the retina into a tiny blob of pigmented receptors and lead light from the very distant corneal facets to it via biological fiber optics. This can produce an eye with excellent visual acuity an ...
... reduce the visibility of these otherwise transparent plankton. A more profound modification is to collapse the retina into a tiny blob of pigmented receptors and lead light from the very distant corneal facets to it via biological fiber optics. This can produce an eye with excellent visual acuity an ...
12 Cell Culture Models of the Corneal Epithelium and
... Potential disadvantages of ocular drug delivery may include the rather low applicable volume and rapid drainage of the drug solution through nasolacrimal ducts, resulting in a low ocular bioavailability. Moreover, all pharmacopoeias require a low irritant potential for eye medications. To assess the ...
... Potential disadvantages of ocular drug delivery may include the rather low applicable volume and rapid drainage of the drug solution through nasolacrimal ducts, resulting in a low ocular bioavailability. Moreover, all pharmacopoeias require a low irritant potential for eye medications. To assess the ...
Computed Tomography of Ocular Colobomas
... case 2 (fig . 2). More extensive eversion (fig. 4C) causes the globe to elongate as in case 1 (fig. 1). Retinal cysts may be formed along with a coloboma if there is very extensive retinal proliferation and separation of the inner and outer retinal layers (fig . 5) [2 , 4]. These cysts communicate w ...
... case 2 (fig . 2). More extensive eversion (fig. 4C) causes the globe to elongate as in case 1 (fig. 1). Retinal cysts may be formed along with a coloboma if there is very extensive retinal proliferation and separation of the inner and outer retinal layers (fig . 5) [2 , 4]. These cysts communicate w ...
Sparrow RPE heath and disease 2010
... enter the RPE cell from the subretinal space both by diffusion across the RPE apical membrane and by carbonic anhydrase-mediated conversion to HCO3 in the apical membrane followed by transmembrane transport via the electrogenic Na+/2HCO3 cotransporter [57, 59, 66]. Diffusion of CO2 across the basola ...
... enter the RPE cell from the subretinal space both by diffusion across the RPE apical membrane and by carbonic anhydrase-mediated conversion to HCO3 in the apical membrane followed by transmembrane transport via the electrogenic Na+/2HCO3 cotransporter [57, 59, 66]. Diffusion of CO2 across the basola ...
vitreoretinal surgery
... highest cut rate possible because the machine controls duty cycle. This gives me confidence that the duty cycle is always at least 50%,” said Dr. Rizzo. One result of the Constellation’s intuitive duty cycle control is that it allows the surgeon to reduce the number of parameter adjustments that are ...
... highest cut rate possible because the machine controls duty cycle. This gives me confidence that the duty cycle is always at least 50%,” said Dr. Rizzo. One result of the Constellation’s intuitive duty cycle control is that it allows the surgeon to reduce the number of parameter adjustments that are ...
A Review of the Vascular Anatomy of the Optic Nerve Head
... that the neuroretinal rim is pale [11, 14]. Fluorescein fundus angiography can be used in the early stages of AION which show filling defects in the optic disc, peripapillary choroid and/or choroidal watershed zones with late disc staining [11, 15-17]. In GCA, the nasal blood supply is often affecte ...
... that the neuroretinal rim is pale [11, 14]. Fluorescein fundus angiography can be used in the early stages of AION which show filling defects in the optic disc, peripapillary choroid and/or choroidal watershed zones with late disc staining [11, 15-17]. In GCA, the nasal blood supply is often affecte ...
A Review of the Vascular Anatomy of the Optic Nerve Head
... To demonstrate the vascular complexity of the optic head, it is generally accepted that the prelaminar region is supplied by the peripapillary choroid composed of the scleral short posterior ciliary system and the recurrent choroidal arteries; the lamina cribrosa is supplied by centripetal branches ...
... To demonstrate the vascular complexity of the optic head, it is generally accepted that the prelaminar region is supplied by the peripapillary choroid composed of the scleral short posterior ciliary system and the recurrent choroidal arteries; the lamina cribrosa is supplied by centripetal branches ...
Retinal hemorrhages as one of complications of optic disc drusen
... drusen may vary in their appearance and position throughout the life of the patient, from those deeply immersed in the optic nerve to the ones placed on the surface of the nerve [12–14]. The prevalence of retinal hemorrhages in patients with ODD is from 2% to 10% [15–18]. Sanders et al. distinguish ...
... drusen may vary in their appearance and position throughout the life of the patient, from those deeply immersed in the optic nerve to the ones placed on the surface of the nerve [12–14]. The prevalence of retinal hemorrhages in patients with ODD is from 2% to 10% [15–18]. Sanders et al. distinguish ...
Macular Buckle for Retinal detachment Related to
... The peripheral retina must be examined for any holes or breaks that may require laser treatment. A perfluorocarbon liquid-air exchange is then performed. Finally, nonexpansible concentration of gas or silicone oil can be used as a temporary tamponade. The patient is instructed to position face-down ...
... The peripheral retina must be examined for any holes or breaks that may require laser treatment. A perfluorocarbon liquid-air exchange is then performed. Finally, nonexpansible concentration of gas or silicone oil can be used as a temporary tamponade. The patient is instructed to position face-down ...
PDF
... mapped onto a schematic of the mutated gene. RT-PCR was performed on total RNA samples isolated from 3 dpf wild-type AB, wild-type/heterozygous siblings and/or homozygous mutant embryos from each line, and transcript levels were assayed using primer sets flanking and/or downstream of the proviral in ...
... mapped onto a schematic of the mutated gene. RT-PCR was performed on total RNA samples isolated from 3 dpf wild-type AB, wild-type/heterozygous siblings and/or homozygous mutant embryos from each line, and transcript levels were assayed using primer sets flanking and/or downstream of the proviral in ...
Photoreceptor cell
A photoreceptor cell is a specialized type of neuron found in the retina that is capable of phototransduction. The great biological importance of photoreceptors is that they convert light (visible electromagnetic radiation) into signals that can stimulate biological processes. To be more specific, photoreceptor proteins in the cell absorb photons, triggering a change in the cell's membrane potential.The two classic photoreceptor cells are rods and cones, each contributing information used by the visual system to form a representation of the visual world, sight. The rods are narrower than the cones and distributed differently across the retina, but the chemical process in each that supports phototransduction is similar. A third class of photoreceptor cells was discovered during the 1990s: the photosensitive ganglion cells. These cells do not contribute to sight directly, but are thought to support circadian rhythms and pupillary reflex.There are major functional differences between the rods and cones. Rods are extremely sensitive, and can be triggered by a single photon. At very low light levels, visual experience is based solely on the rod signal. This explains why colors cannot be seen at low light levels: only one type of photoreceptor cell is active.Cones require significantly brighter light (i.e., a larger numbers of photons) in order to produce a signal. In humans, there are three different types of cone cell, distinguished by their pattern of response to different wavelengths of light. Color experience is calculated from these three distinct signals, perhaps via an opponent process. The three types of cone cell respond (roughly) to light of short, medium, and long wavelengths. Note that, due to the principle of univariance, the firing of the cell depends upon only the number of photons absorbed. The different responses of the three types of cone cells are determined by the likelihoods that their respective photoreceptor proteins will absorb photons of different wavelengths. So, for example, an L cone cell contains a photoreceptor protein that more readily absorbs long wavelengths of light (i.e., more ""red""). Light of a shorter wavelength can also produce the same response, but it must be much brighter to do so.The human retina contains about 120 million rod cells and 6 million cone cells. The number and ratio of rods to cones varies among species, dependent on whether an animal is primarily diurnal or nocturnal. Certain owls, such as the tawny owl, have a tremendous number of rods in their retinae. In addition, there are about 2.4 million to 3 million ganglion cells in the human visual system, the axons of these cells form the 2 optic nerves, 1 to 2% of them photosensitive.The pineal and parapineal glands are photoreceptive in non-mammalian vertebrates, but not in mammals. Birds have photoactive cerebrospinal fluid (CSF)-contacting neurons within the paraventricular organ that respond to light in the absence of input from the eyes or neurotransmitters. Invertebrate photoreceptors in organisms such as insects and molluscs are different in both their morphological organization and their underlying biochemical pathways. Described here are human photoreceptors.