Retained Intraocular Foreign Body
... A key principle in removing any IOFB from the posterior segment is obtaining excellent visibility. Using an external magnet with poor visibility can cause a myriad of complications. External magnets are used for magnetic IOFBs when the view is excellent and the IOFB is not impacted or encapsulated b ...
... A key principle in removing any IOFB from the posterior segment is obtaining excellent visibility. Using an external magnet with poor visibility can cause a myriad of complications. External magnets are used for magnetic IOFBs when the view is excellent and the IOFB is not impacted or encapsulated b ...
The spectral transmission of ocular media suggests ultraviolet
... mammalian lenses examined ranged from those in young murid rodents as well as juvenile hedgehogs, which transmitted large amounts of UV radiation (50% transmission 310–320 nm), to those of primates, sciurid rodents, meerkats and tree shrews that were visibly yellow and prevented UV radiation from re ...
... mammalian lenses examined ranged from those in young murid rodents as well as juvenile hedgehogs, which transmitted large amounts of UV radiation (50% transmission 310–320 nm), to those of primates, sciurid rodents, meerkats and tree shrews that were visibly yellow and prevented UV radiation from re ...
Phakic IOL - Augenklinik Teufen
... • These light rays are focused directly onto the retina, the lightsensitive tissue lining the back of the eye. • The retina converts light rays into impulses, sent through the optic nerve to your brain, where they are recognized as images. ...
... • These light rays are focused directly onto the retina, the lightsensitive tissue lining the back of the eye. • The retina converts light rays into impulses, sent through the optic nerve to your brain, where they are recognized as images. ...
Reproducibility of Nerve Fiber Layer Thickness Measurements by
... source, interference of light reflected from the signal and reference beams occurs only when the delay of the reflections is nearly matched, resulting in high resolution. This instrument has a theoretical axial resolution of approximately 10 m.14,16 In the commercially available OCT, RNFL is differ ...
... source, interference of light reflected from the signal and reference beams occurs only when the delay of the reflections is nearly matched, resulting in high resolution. This instrument has a theoretical axial resolution of approximately 10 m.14,16 In the commercially available OCT, RNFL is differ ...
Free radical tissue damages in the anterior segment of the eye in
... oxygen-free radicals, as is the case in chronic uveitis.16 Histochemically, peroxidized carbonyl products are located primarily on the anterior border layer and posterior epithelium of the iris and, to a lesser extent, on the trabecular meshwork, and the corneal endothelium in EAU. Numerous PMNs wer ...
... oxygen-free radicals, as is the case in chronic uveitis.16 Histochemically, peroxidized carbonyl products are located primarily on the anterior border layer and posterior epithelium of the iris and, to a lesser extent, on the trabecular meshwork, and the corneal endothelium in EAU. Numerous PMNs wer ...
A brushfire in the eye
... of cases, respectively.14 Because the macula is responsible for the detection of fine details (vision better than 20/200) and the optic nerve transmits all visual information from the retina to the brain, it is not surprising that CMV retinitis involving these structures can cause blindness. In some ...
... of cases, respectively.14 Because the macula is responsible for the detection of fine details (vision better than 20/200) and the optic nerve transmits all visual information from the retina to the brain, it is not surprising that CMV retinitis involving these structures can cause blindness. In some ...
Free radical tissue damages in the anterior segment of the
... oxygen-free radicals, as is the case in chronic uveitis.16 Histochemically, peroxidized carbonyl products are located primarily on the anterior border layer and posterior epithelium of the iris and, to a lesser extent, on the trabecular meshwork, and the corneal endothelium in EAU. Numerous PMNs wer ...
... oxygen-free radicals, as is the case in chronic uveitis.16 Histochemically, peroxidized carbonyl products are located primarily on the anterior border layer and posterior epithelium of the iris and, to a lesser extent, on the trabecular meshwork, and the corneal endothelium in EAU. Numerous PMNs wer ...
entra-ocular hydatid cyst - British Journal of Ophthalmology
... mass was seen to occupy the entire posterior segment of the eyeball. The outer coat of this mass could easily be separated from the retina and was smooth and white like the outer surface of a hard-boiled egg. Inside this big cyst were seen numerous small daughter cysts ranging in diameter from 1 to ...
... mass was seen to occupy the entire posterior segment of the eyeball. The outer coat of this mass could easily be separated from the retina and was smooth and white like the outer surface of a hard-boiled egg. Inside this big cyst were seen numerous small daughter cysts ranging in diameter from 1 to ...
Optical properties of the mouse eye
... Biss et al. found it difficult to measure the wavefront using back-scattered light due to very large wavefront sensor spots [7]. To avoid this poor spot quality, they used the fluorescence signal from a single layer of labeled retinal cells rather than back-scattered light for wavefront sensing. Thi ...
... Biss et al. found it difficult to measure the wavefront using back-scattered light due to very large wavefront sensor spots [7]. To avoid this poor spot quality, they used the fluorescence signal from a single layer of labeled retinal cells rather than back-scattered light for wavefront sensing. Thi ...
Argyll Robertson Pupil
... accepted as a pathognomonic sign of neurosyphilis, and this sign has since been identified with other central nervous system diseases as well. PHYSIOLOGY Light Reflex From an inverted image on the light-sensitive cells of the retina, impulses pass through the optic nerve to the optic tract via the o ...
... accepted as a pathognomonic sign of neurosyphilis, and this sign has since been identified with other central nervous system diseases as well. PHYSIOLOGY Light Reflex From an inverted image on the light-sensitive cells of the retina, impulses pass through the optic nerve to the optic tract via the o ...
The third dimension in the primary visual cortex
... though a precondition for it. Still, it provided the impetus for the enquiry: if border-orientation is a criterion for sorting and reassembling the cortical input according to a parameter set that interrupts but does not disarrange the orderly progression of distance in visual space, could this also ...
... though a precondition for it. Still, it provided the impetus for the enquiry: if border-orientation is a criterion for sorting and reassembling the cortical input according to a parameter set that interrupts but does not disarrange the orderly progression of distance in visual space, could this also ...
giulia steigerwalt
... whether they are getting closer to a specific retinal region chosen by the ophthalmologist. The patient’s perception of the sound increases his/her conscious attention, thereby facilitating the lock-in of the visual target and increasing the time the fixation target itself remains on the retina. Thi ...
... whether they are getting closer to a specific retinal region chosen by the ophthalmologist. The patient’s perception of the sound increases his/her conscious attention, thereby facilitating the lock-in of the visual target and increasing the time the fixation target itself remains on the retina. Thi ...
The effects of choroidal or ciliary nerve transection on myopic
... the inferior retina (Fig. 1). Examination of plasticembedded sections from the affected part of the temporal retina revealed that the outer retina had degenerated (Figs. 2, 3). All photoreceptor outer and inner segments and all photoreceptor cell bodies (and the entire outer nuclear layer) were abse ...
... the inferior retina (Fig. 1). Examination of plasticembedded sections from the affected part of the temporal retina revealed that the outer retina had degenerated (Figs. 2, 3). All photoreceptor outer and inner segments and all photoreceptor cell bodies (and the entire outer nuclear layer) were abse ...
Cortical representation of visual three-dimensional space
... appears as thick when viewed from 20 cm or 80 cm despite the fact that disparities are smaller by a factor of 16. Theoretically, it should appear to flatten when moved away from the observer because the size of a retinal image changes almost in inverse proportion to the viewing distance, whereas ret ...
... appears as thick when viewed from 20 cm or 80 cm despite the fact that disparities are smaller by a factor of 16. Theoretically, it should appear to flatten when moved away from the observer because the size of a retinal image changes almost in inverse proportion to the viewing distance, whereas ret ...
Final Protocol - Word 1142 KB - Medical Services Advisory Committee
... diabetes, and may result in central but not peripheral vision loss. Macular ischemia occurs when the small blood vessels become so damaged that they become obstructed, depriving the macula of sufficient nutrients. The early stages of DR are referred to as non-proliferative or background diabetic ret ...
... diabetes, and may result in central but not peripheral vision loss. Macular ischemia occurs when the small blood vessels become so damaged that they become obstructed, depriving the macula of sufficient nutrients. The early stages of DR are referred to as non-proliferative or background diabetic ret ...
Comparison of Macular Thickness and Volume in Amblyopic
... Park et al21 studied macular thickness in 20 amblyopic patients using spectral domain OCT (SD-OCT); amblyopia was caused by strabismus, anisoastigmatism and unilateral ptosis. In their study, they found significant thinning of several retinal layers in amblyopic eyes, especially in the ganglion cell ...
... Park et al21 studied macular thickness in 20 amblyopic patients using spectral domain OCT (SD-OCT); amblyopia was caused by strabismus, anisoastigmatism and unilateral ptosis. In their study, they found significant thinning of several retinal layers in amblyopic eyes, especially in the ganglion cell ...
ARVO 2015 Annual Meeting Abstracts 376 Glaucoma Tuesday, May
... was evaluated by immunostaining of 4-hydroxy-2-nonenal (4-HNE). The cytotoxicity was assessed by LDH activity assay and Annexin V/ propidium iodide (PI) staining. Cells transfected with GPx4 siRNA or control siRNA were treated with glutamate (final concentration: 2 mM), and the cytotoxicity was eval ...
... was evaluated by immunostaining of 4-hydroxy-2-nonenal (4-HNE). The cytotoxicity was assessed by LDH activity assay and Annexin V/ propidium iodide (PI) staining. Cells transfected with GPx4 siRNA or control siRNA were treated with glutamate (final concentration: 2 mM), and the cytotoxicity was eval ...
Influence of Axial Length on Thickness Measurements Using
... for eyes with moderate ametropia is related linearly to axial length.11–16,29–31 Measures can be rescaled to match those of an emmetropic eye. Specifically, several investigators11,12,29 have used a modified Littmann’s formula20 that incorporates a magnification factor of the eye to make this correc ...
... for eyes with moderate ametropia is related linearly to axial length.11–16,29–31 Measures can be rescaled to match those of an emmetropic eye. Specifically, several investigators11,12,29 have used a modified Littmann’s formula20 that incorporates a magnification factor of the eye to make this correc ...
An Ocularist`s Approach to Human Iris Synthesis
... anterior surface is divided into the ciliary zone and the pupil zone by a thickened region called the collarette. There are four layers in the iris: the anterior border layer, the stroma, the dilator pupillae muscle and the posterior pigment epithelium (Figure 2). The anterior border layer consists ...
... anterior surface is divided into the ciliary zone and the pupil zone by a thickened region called the collarette. There are four layers in the iris: the anterior border layer, the stroma, the dilator pupillae muscle and the posterior pigment epithelium (Figure 2). The anterior border layer consists ...
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 ...
Primary optic nerve meningioma - British Journal of Ophthalmology
... ocular muscles attempting to overcome the mechanical resistance provided by the thickened and abnormal optic nerve. The slight proptosis observed in many of the patients can be attributed to the straightening of the normal S shape of the optic nerve within the orbit. More marked proptosis occurs if ...
... ocular muscles attempting to overcome the mechanical resistance provided by the thickened and abnormal optic nerve. The slight proptosis observed in many of the patients can be attributed to the straightening of the normal S shape of the optic nerve within the orbit. More marked proptosis occurs if ...
A1The eye in detail
... Retina's simplified axial organization. The retina is a stack of several neuronal layers. Light is concentrated from the eye and passes across these layers (from left to right) to hit the photoreceptors (right layer). This elicits chemical transformation mediating a propagation of signal to the bip ...
... Retina's simplified axial organization. The retina is a stack of several neuronal layers. Light is concentrated from the eye and passes across these layers (from left to right) to hit the photoreceptors (right layer). This elicits chemical transformation mediating a propagation of signal to the bip ...
Optic Disc Swelling (including Papilloedema)
... at its head into the globe. The time course for the development of papilloedema depends on the cause. It may be weeks if the rise in ICP is slow and mild, but it can occur within a day if the ICP rises suddenly and severely. If there is optic atrophy then there will be little or no papilloedema, eve ...
... at its head into the globe. The time course for the development of papilloedema depends on the cause. It may be weeks if the rise in ICP is slow and mild, but it can occur within a day if the ICP rises suddenly and severely. If there is optic atrophy then there will be little or no papilloedema, eve ...
Retina
The retina (/ˈrɛtɪnə/ RET-i-nə, pl. retinae, /ˈrɛtiniː/; from Latin rēte, meaning ""net"") is the third and inner coat of the eye which is a light-sensitive layer of tissue. The optics of the eye create an image of the visual world on the retina (through the cornea and lens), which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical events that ultimately trigger nerve impulses. These are sent to various visual centres of the brain through the fibres of the optic nerve.In vertebrate embryonic development, the retina and the optic nerve originate as outgrowths of the developing brain, so the retina is considered part of the central nervous system (CNS) and is actually brain tissue. It is the only part of the CNS that can be visualized non-invasively.The retina is a layered structure with several layers of neurons interconnected by synapses. The only neurons that are directly sensitive to light are the photoreceptor cells. These are mainly of two types: the rods and cones. Rods function mainly in dim light and provide black-and-white vision, while cones support daytime vision and the perception of colour. A third, much rarer type of photoreceptor, the intrinsically photosensitive ganglion cell, is important for reflexive responses to bright daylight.Neural signals from the rods and cones undergo processing by other neurons of the retina. The output takes the form of action potentials in retinal ganglion cells whose axons form the optic nerve. Several important features of visual perception can be traced to the retinal encoding and processing of light.