Surgical outcomes of phototherapeutic keratectomy on
... disease of the anterior cornea. The disease presents a variety of symptoms and morphological signs. Most people with EBMD are asymptomatic, but approximately 10% experience problems with refraction and visual acuity and/or painful recurrent erosions of the corneal epithelium. Many different treatmen ...
... disease of the anterior cornea. The disease presents a variety of symptoms and morphological signs. Most people with EBMD are asymptomatic, but approximately 10% experience problems with refraction and visual acuity and/or painful recurrent erosions of the corneal epithelium. Many different treatmen ...
to PDF of Visual and Anatomic Outcomes of Vitrectomy
... was converted to logarithm of the minimum angle of resolution (LogMAR) visual acuity scores for statistical analysis. Eyes for which Snellen visual acuity could not be measured were assigned LogMAR scores according to a scale adapted from Holladay in which “counting fingers” = 2.0, “hand motions” = ...
... was converted to logarithm of the minimum angle of resolution (LogMAR) visual acuity scores for statistical analysis. Eyes for which Snellen visual acuity could not be measured were assigned LogMAR scores according to a scale adapted from Holladay in which “counting fingers” = 2.0, “hand motions” = ...
visual field defects in optic chiasm lesions
... Bitemporal visual field defects are classically associated with optic chiasm compression. The inferonasal retinal nerve fibres cross low and anteriorly, and therefore are most vulnerable to damage from expanding sellar lesions, typically pituitary adenomas. Compression of the optic chiasm may be asy ...
... Bitemporal visual field defects are classically associated with optic chiasm compression. The inferonasal retinal nerve fibres cross low and anteriorly, and therefore are most vulnerable to damage from expanding sellar lesions, typically pituitary adenomas. Compression of the optic chiasm may be asy ...
Retinal Vein Occlusions
... occur in a wide variety of shapes and sizes; they are usually concentrated in the posterior pole, but may be seen throughout the retina. Hemorrhages in the superficial retina may be so prominent about the posterior pole that the underlying retina is obscured. Many hemorrhages are flame shaped, refle ...
... occur in a wide variety of shapes and sizes; they are usually concentrated in the posterior pole, but may be seen throughout the retina. Hemorrhages in the superficial retina may be so prominent about the posterior pole that the underlying retina is obscured. Many hemorrhages are flame shaped, refle ...
Normal Physiology Specialty 7.110201 “Pharmaciya”" 1 Year of
... 69. What connections take part in transfer of excitation in visual receptors? A. Calmoduline B. Retinal C. Opsin D. All listed E. Calcium ANSWER: D 70. How the amplitude of hyperpolarization in an eye changes at increase in its illumination? A. First decreases, and then is restored B. Does not chang ...
... 69. What connections take part in transfer of excitation in visual receptors? A. Calmoduline B. Retinal C. Opsin D. All listed E. Calcium ANSWER: D 70. How the amplitude of hyperpolarization in an eye changes at increase in its illumination? A. First decreases, and then is restored B. Does not chang ...
Retinal Vein Occlusions - Kashyap Memorial Eye Hospital
... Neovascularization of the iris and neovascular glaucoma are uncommon and occur in only approximately 1% of affected eyes. More commonly, neovascularization of the disc occurs in approximately 10% of eyes, and neovascularization elsewhere occurs in approximately 20% of eyes. Generally, retinal neovas ...
... Neovascularization of the iris and neovascular glaucoma are uncommon and occur in only approximately 1% of affected eyes. More commonly, neovascularization of the disc occurs in approximately 10% of eyes, and neovascularization elsewhere occurs in approximately 20% of eyes. Generally, retinal neovas ...
Use of Optical Coherence Tomography to Assess Variations
... Disclosure: M.C.C. Lim, None; S.-T. Hoh, None; P.J. Foster, None; T.-H. Lim, None; S.-J. Chew, None; S.K.L. Seah, None; T. Aung, None The publication costs of this article were defrayed in part by page charge payment. This article must therefore be marked “advertisement” in accordance with 18 U.S.C. ...
... Disclosure: M.C.C. Lim, None; S.-T. Hoh, None; P.J. Foster, None; T.-H. Lim, None; S.-J. Chew, None; S.K.L. Seah, None; T. Aung, None The publication costs of this article were defrayed in part by page charge payment. This article must therefore be marked “advertisement” in accordance with 18 U.S.C. ...
The intraorbital course of ophthalmic artery and its
... part of the OA surrounds the optic nerve, lies free within the extra-orbital fat and slightly adheres to the optic nerve sheath [8]. In our study, the first part of the OA usually lay in very close relationship with the optic nerve, free in the fat of the orbit and attached to the nerve only by fat ...
... part of the OA surrounds the optic nerve, lies free within the extra-orbital fat and slightly adheres to the optic nerve sheath [8]. In our study, the first part of the OA usually lay in very close relationship with the optic nerve, free in the fat of the orbit and attached to the nerve only by fat ...
ARVO 2016 Annual Meeting Abstracts 539 Glaucoma Thursday
... Results: Pilocarpine maximally decreased IOP by 23±3% at 1h postdose in OHT eyes and 14±3% in the fellow normal eyes. The baseline IOP (±SEM) was 33±1 mmHg and 24±1 mmHg in OHT and normal eyes, respectively. The pupil diameter in both eyes was decreased similarly by about 70% compared to pre-dose re ...
... Results: Pilocarpine maximally decreased IOP by 23±3% at 1h postdose in OHT eyes and 14±3% in the fellow normal eyes. The baseline IOP (±SEM) was 33±1 mmHg and 24±1 mmHg in OHT and normal eyes, respectively. The pupil diameter in both eyes was decreased similarly by about 70% compared to pre-dose re ...
Chapter Three Vestibular System
... The normal push-pull functioning of the canal pairs is important, since excitatory stimuli are better vestibular stimuli than inhibitory ones – a phenomenon first described by Ewald (1892). Ewald applied positive and negative pressure to each of the canals, making three observations that are now kno ...
... The normal push-pull functioning of the canal pairs is important, since excitatory stimuli are better vestibular stimuli than inhibitory ones – a phenomenon first described by Ewald (1892). Ewald applied positive and negative pressure to each of the canals, making three observations that are now kno ...
Albinism in life
... A medical doctor (ophthalmologist) or optometrist should conduct your child's eye examination. The exam will include an assessment of potential nystagmus, strabismus and photophobia. The doctor will use a device to visually inspect the retina and determine if there are signs of abnormal development. ...
... A medical doctor (ophthalmologist) or optometrist should conduct your child's eye examination. The exam will include an assessment of potential nystagmus, strabismus and photophobia. The doctor will use a device to visually inspect the retina and determine if there are signs of abnormal development. ...
this PDF file
... Central retinal vein occlusion (CRVO) spans a clinical spectrum from mild alteration in venous flow apparent as an impending vein occlusion to a very severe predominantly occlusive ischemic CRVO. Based on the quantum of ischemia or capillary non-perfusion in the standard ETDRS fields, the Central re ...
... Central retinal vein occlusion (CRVO) spans a clinical spectrum from mild alteration in venous flow apparent as an impending vein occlusion to a very severe predominantly occlusive ischemic CRVO. Based on the quantum of ischemia or capillary non-perfusion in the standard ETDRS fields, the Central re ...
VITREOUS HEMORRHAGE
... Iron especially in its ferrous form, binds to the acid mucopolysaccharides at the posterior hyaloid face, perivascular tissue, optic nerve head and trabecular meshwork. Toxic effects are first noticed around these structures. Choroids and ciliary muscle remain largely unaffected. ...
... Iron especially in its ferrous form, binds to the acid mucopolysaccharides at the posterior hyaloid face, perivascular tissue, optic nerve head and trabecular meshwork. Toxic effects are first noticed around these structures. Choroids and ciliary muscle remain largely unaffected. ...
Characterization of the day-night variation of retinal melatonin
... pineal gland of each animal, we have shown that the day-night variations in both organs are synchronous and regulated by environmental lighting in a similar manner; high nighttime levels are suppressed by light whereas the rhythms persist in darkness. We also dissected retina from pigment epithelium ...
... pineal gland of each animal, we have shown that the day-night variations in both organs are synchronous and regulated by environmental lighting in a similar manner; high nighttime levels are suppressed by light whereas the rhythms persist in darkness. We also dissected retina from pigment epithelium ...
Sonographic ocular findings in diabetic retinopathy ARTIGO
... giving similar sonography appearance as fresh vitreous hemorrhage, while vitreous hemorrhage distributed may layer inferiorly due to gravitational forces. As the hemorrhage matures and organizes, echogenicity increases dramatically. With time, the hemorrhage will resorb, often producing an extremely ...
... giving similar sonography appearance as fresh vitreous hemorrhage, while vitreous hemorrhage distributed may layer inferiorly due to gravitational forces. As the hemorrhage matures and organizes, echogenicity increases dramatically. With time, the hemorrhage will resorb, often producing an extremely ...
The changing paradigm of outflow resistance generation
... They described an apparently unique feature of many of these inner wall cells, namely structures that were named ‘‘giant vacuoles’’ that appear to be within the cells (Figs. 3 and 4A). These structures (1–10 mm in width, 1–7 mm in height, extending to 20 mm in length) are not intracellular structure ...
... They described an apparently unique feature of many of these inner wall cells, namely structures that were named ‘‘giant vacuoles’’ that appear to be within the cells (Figs. 3 and 4A). These structures (1–10 mm in width, 1–7 mm in height, extending to 20 mm in length) are not intracellular structure ...
Light Energy - Wallingford Public Schools
... Using what you know about light, decide what periscope design would be the best tool. Your proposal to the submarine company should include: • explain which periscope you recommend and why • an illustration to show the path of light through your periscope • an explanation why you didn’t recommend th ...
... Using what you know about light, decide what periscope design would be the best tool. Your proposal to the submarine company should include: • explain which periscope you recommend and why • an illustration to show the path of light through your periscope • an explanation why you didn’t recommend th ...
Central retinal thickness is positively correlated with
... of an annulus of 10-degrees diameter. HFP uses MP’s spectral and anatomical properties; MP absorbs strongly in the blue portion of the spectrum, thereby attenuating the spectral sensitivity of macular photoreceptors to blue light. During this test, the subject fixes on a central test field which fli ...
... of an annulus of 10-degrees diameter. HFP uses MP’s spectral and anatomical properties; MP absorbs strongly in the blue portion of the spectrum, thereby attenuating the spectral sensitivity of macular photoreceptors to blue light. During this test, the subject fixes on a central test field which fli ...
Light, dark, and melatonin: emerging evidence for the
... whereas intrinsically photosensitive retinal ganglion cells expressing melanopsin are light sensitive from birth.26 These photosensitive retinal ganglion cells are directly connected to (1) the suprachiasmatic nucleus for circadian photoentrainment, (2) the lateral geniculate body possibly contribut ...
... whereas intrinsically photosensitive retinal ganglion cells expressing melanopsin are light sensitive from birth.26 These photosensitive retinal ganglion cells are directly connected to (1) the suprachiasmatic nucleus for circadian photoentrainment, (2) the lateral geniculate body possibly contribut ...
Wavefront Aberrations and Peripheral Vision
... tissue. Its optical components are designed to form an image of the world around us, which is then recorded and perceived by the retina and the brain. Even small imperfections in this process will lower the quality of vision. Most common are the refractive errors, which mean that the best image is n ...
... tissue. Its optical components are designed to form an image of the world around us, which is then recorded and perceived by the retina and the brain. Even small imperfections in this process will lower the quality of vision. Most common are the refractive errors, which mean that the best image is n ...
The cranial nerves
... The trigeminal motor nucleus supplies masticatory and a few other muscles through the mandibular dMsion of V, The facialmotor nucleus supplies the facial muscles and the stapedius. The lower half of the face is controlled by the contralateral cerebral hemisphere. The upper half is bilaterally contro ...
... The trigeminal motor nucleus supplies masticatory and a few other muscles through the mandibular dMsion of V, The facialmotor nucleus supplies the facial muscles and the stapedius. The lower half of the face is controlled by the contralateral cerebral hemisphere. The upper half is bilaterally contro ...
surgical anatomy for endoscopic sphenoethmoidectomy
... anterior and posterior ethmoid cells. ◦ Pneumatization of the suprabullar recess: insertion of basal lamella to skull base superiorly is located posterior to nferior part of oblique segment ◦ Pneumatization of retrobullar recess: inferior part of basal lamella assumes a more posterior position a ...
... anterior and posterior ethmoid cells. ◦ Pneumatization of the suprabullar recess: insertion of basal lamella to skull base superiorly is located posterior to nferior part of oblique segment ◦ Pneumatization of retrobullar recess: inferior part of basal lamella assumes a more posterior position a ...
Quantification of retinal layer thickness changes in acute macular
... There was no difference in terms of INL (37±8 mm vs 38±6 mm, p=0.9) and OPL (45±19 mm vs 33±16 mm, p=0.1) thickness between the study eyes and the fellow eyes at baseline. However the ONL at the respective area was significantly thinner in the study eyes compared with the fellow eyes (51±21 mm vs 73 ...
... There was no difference in terms of INL (37±8 mm vs 38±6 mm, p=0.9) and OPL (45±19 mm vs 33±16 mm, p=0.1) thickness between the study eyes and the fellow eyes at baseline. However the ONL at the respective area was significantly thinner in the study eyes compared with the fellow eyes (51±21 mm vs 73 ...
Quantification of retinal layer thickness changes in acute macular
... There was no difference in terms of INL (37±8 mm vs 38±6 mm, p=0.9) and OPL (45±19 mm vs 33±16 mm, p=0.1) thickness between the study eyes and the fellow eyes at baseline. However the ONL at the respective area was significantly thinner in the study eyes compared with the fellow eyes (51±21 mm vs 73 ...
... There was no difference in terms of INL (37±8 mm vs 38±6 mm, p=0.9) and OPL (45±19 mm vs 33±16 mm, p=0.1) thickness between the study eyes and the fellow eyes at baseline. However the ONL at the respective area was significantly thinner in the study eyes compared with the fellow eyes (51±21 mm vs 73 ...
THE PTERYGOPALATINE FOSSA MAXILLARY NERVE EAR
... as it contracts longitudinally, pushing against one wall while the tensor veli pala/ni pulls on the other The nerves of the pharyngotympanic tube arise from the tympanic plexus which is formed by fibers of the glossopharyngeal nerve (CN IX). Anteriorly, the tube also receives fibers from the ptery ...
... as it contracts longitudinally, pushing against one wall while the tensor veli pala/ni pulls on the other The nerves of the pharyngotympanic tube arise from the tympanic plexus which is formed by fibers of the glossopharyngeal nerve (CN IX). Anteriorly, the tube also receives fibers from the ptery ...
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.