query: a progressive degeneration of the macula lutea of the retina is called

pos: Macula of retina from the pupil, as in ophthalmoscopy or retinal photography. Whereas loss of peripheral vision may go unnoticed for some time, damage to the macula will result in loss of central vision, which is usually immediately obvious. The progressive destruction of the macula is a disease known as macular degeneration and can sometimes lead to the creation of a macular hole. Macular holes are rarely caused by trauma, but if a severe blow is delivered it can burst the blood vessels going to the macula, destroying it. Visual input from the macula occupies a substantial portion of the brain's visual capacity.

pos: Macula of retina example in macular degeneration. The clinical macula is seen when viewed from the pupil, as in ophthalmoscopy or retinal photography. The term macula lutea comes from Latin "macula", "spot", and "lutea", "yellow". The macula is an oval-shaped pigmented area near the center of the retina of the human eye and some other animalian eyes. The macula in humans has a diameter of around and is subdivided into the umbo, foveola, foveal avascular zone, fovea, parafovea, and perifovea areas. The anatomical macula at is much larger than the clinical macula which, at , corresponds to the anatomical fovea. The clinical macula

pos: Macula of retina from the pupil, as in ophthalmoscopy or retinal photography. Whereas loss of peripheral vision may go unnoticed for some time, damage to the macula will result in loss of central vision, which is usually immediately obvious. The progressive destruction of the macula is a disease known as macular degeneration and can sometimes lead to the creation of a macular hole. Macular holes are rarely caused by trauma, but if a severe blow is delivered it can burst the blood vessels going to the macula, destroying it. Visual input from the macula occupies a substantial portion of the brain's visual capacity.

pos: Macula of retina light that enter the eye, and acts as a natural sunblock (analogous to sunglasses) for this area of the retina. The yellow color comes from its content of lutein and zeaxanthin, which are yellow xanthophyll carotenoids, derived from the diet. Zeaxanthin predominates at the macula, while lutein predominates elsewhere in the retina. There is some evidence that these carotenoids protect the pigmented region from some types of macular degeneration. A formulation of 10 mg lutein and 2 mg zeaxanthin has been shown to reduce the risk of age-related macular degeneration progressing to advanced stages, although these carotenoids have not been

pos: PSMD1 Rpn2 in 15 macula degeneration patients compared to the control subjects, suggesting that this protein could be a biomarker for this condition. Age-related macular degeneration is the leading cause of blindness in the world. Evidence is accumulating that the suppression of the UPS contributes to the increase of toxic proteins and inflammation in retina pigment epithelium, the functional abnormalities and/or the degeneration of which are believed to be the initiators and major pathologies of macula degeneration. There are only limited options for the treatment of macular degeneration, thus early identification of susceptibility and preventive measures are important therapeutic strategies. New

pos: Aging and society positive perceptions of the environment around them. This can lead to isolation and possible depression in elderly people. Macular degeneration is a common cause of vision loss in elderly people. It diminishes the macula of the eye, which is responsible for clear vision. It causes progressive loss of central vision and possible loss of colour vision. This degeneration is caused by systemic changes in the circulation of waste products and growth of abnormal vessels around the retina causing the photoreceptors not to receive proper images. Though ageing almost always causes this, other possible effects and risk factors include smoking, obesity,

pos: AMD Alliance International world. Macular degeneration is often related to aging, thus the name age-related macular degeneration (AMD or ARMD). The two most common forms of AMD are dry and wet. This more common form, causes varying degrees of sight loss and is identified by the collection of yellow, fatty deposits called drusen in the macula the central part of the retina responsible for clear central vision. Occurs less often (10-15 percent of cases), but the chance for severe sight loss is much greater. It is characterized by development of abnormal, leaky blood vessels in the macula. Scar tissue may form causing irreversible

pos: Macular hole through the hole onto the macula, blurring and distorting central vision. The eye contains a jelly-like substance called the vitreous. Shrinking of the vitreous usually causes the hole. As a person ages, the vitreous becomes watery and begins to pull away from the retina. If the vitreous is firmly attached to the retina when it pulls away, a hole can result. Macular degeneration is a condition affecting the tissues lying under the retina, while a macular hole involves damage from within the eye, at the junction between the vitreous and the retina itself. There is no relationship between the two

pos: Macula of retina distinguish different colors. There is only one type of rod, but the rods are more sensitive than the cones, so in dim light they are the dominant photoreceeptors active, and without information provided by the separate spectral sensitivity of the cones it is impossible to discriminate colors. In the fovea "centralis", cones predominate, and are present at high density. The macula is thus responsible for the central, high-resolution, color vision that is possible in good light; and this kind of vision is impaired if the macula is damaged, for example in macular degeneration. The clinical macula is seen when viewed

pos: Micropsia to occur following the surgical re-attachment for macula-off rhegmatogenous retinal detachment. After surgery, patients may experience micropsia as a result of larger photoreceptor separation by edematous fluid. Macular degeneration typically produces micropsia due to the swelling or bulging of the macula, an oval-shaped yellow spot near the center of the retina in the human eye. The main factors leading to this disease are age, smoking, heredity, and obesity. Some studies show that consuming spinach or collard greens five times a week cuts the risk of macular degeneration by 43%. CSCR is a disease in which a serous detachment of the

pos: Human eye in the U.S. and affects roughly 1.75 million Americans each year. Having lower levels of lutein and zeaxanthin within the macula may be associated with an increase in the risk of age-related macular degeneration.< Lutein and zeaxanthin act as antioxidants that protect the retina and macula from oxidative damage from high-energy light waves. As the light waves enter the eye they excite electrons that can cause harm to the cells in the eye, but before they can cause oxidative damage that may lead to macular degeneration or cataracts. Lutein and zeaxanthin bind to the electron free radical and are reduced

pos: Macular degeneration of those 70 to 80, and nearly 12% of people over 80 years old. Signs and symptoms of macular degeneration include: Macular degeneration by itself will not lead to total blindness. For that matter, only a small number of people with visual impairment are totally blind. In almost all cases, some vision remains, mainly peripheral. Other complicating conditions may lead to such an acute condition (severe stroke or trauma, untreated glaucoma, etc.), but few macular degeneration patients experience total visual loss. The area of the macula comprises only about 2.1% of the retina, and the remaining 97.9% (the peripheral field)

pos: Preferential hyperacuity perimetry distinct objects. Therefore, in retinal diseases such as macular degeneration responses to hyperacuity stimuli may be abnormal long before any changes in visual acuity are observed. Another key element in PHP technology relies on the competition principle. According to this principle, visual attention is "preferably" attracted to the larger object. When two stimuli, which are different in size, are simultaneously and briefly displayed, the observer is more likely to perceive the larger of the two, while missing the other. In a PHP test, the macula (central area of the retina) is scanned with a succession of stimuli, each stimulus consisting

pos: Scotoma such as retinal damage from exposure to high-powered lasers, macular degeneration and brain damage. The term "scotoma" is also used metaphorically in several fields. The common theme of all the figurative senses is of a gap not in visual function but in the mind's perception, cognition, or world view. Symptom-producing, or pathological, scotomata may be due to a wide range of disease processes, affecting any part of the visual system, including the retina (in particular its most sensitive portion, the macula), the optic nerve and even the visual cortex. A pathological scotoma may involve any part of the visual field

pos: Amsler grid Amsler grid The Amsler grid, used since 1945, is a grid of horizontal and vertical lines used to monitor a person's central visual field. The grid was developed by Marc Amsler, a Swiss ophthalmologist. It is a diagnostic tool that aids in the detection of visual disturbances caused by changes in the retina, particularly the macula (e.g. macular degeneration, Epiretinal membrane), as well as the optic nerve and the visual pathway to the brain. In the test, the person looks with each eye separately at the small dot in the center of the grid. Patients with macular disease may see

pos: Microperimetry not, however, considered accurate in the evaluation of pathologies affecting the central part of the retina (macula and fovea centralis) patients with these pathologies are often unable to fixate reliably. By contrast, fundus perimetry, produces reliable results even in patients with unstable or eccentric fixation., or advance macular degeneration. When central vision is compromised, as in the case of macular scotoma, patients develop an eccentric or extra-foveal vision, normally with unstable fixation. The retinal area used by eccentric viewers to substitute the foveal vision is known as the Preferred Retinal Locus (PRL) In Microperimetry systems, the fundus (eye) is imaged

pos: Lutein evening grosbeak, yellow warbler, common yellowthroat and Javan green magpie) deposit lutein obtained from the diet into growing tissues to color their feathers. Although lutein is concentrated in the macula – a small area of the retina responsible for three-color vision – the precise functional role of retinal lutein has not been determined. In 2013, findings of the Age-Related Eye Disease Study showed that a dietary supplement formulation containing lutein reduced progression of age-related macular degeneration (AMD) by 25 percent. However, lutein and zeaxanthin had no overall effect on preventing AMD, but rather "the participants with low dietary intake of

pos: Marc Amsler honor in ophthalmology. Amsler was professor and chief of the Zurich Eye Clinic until 1961. His successor was Rudolf Witmer. He is best known for the Amsler grid test. The Amsler grid was an improvement over the initial work done by the ophthalmologist Edmond Landolt. The grid tests the function of the macula, a part of the retina, so that macular degeneration can be identified. He also contributed to the progress in the understanding of uveitis. Furthermore, he published works on keratoconus. In 1951, Dr. Amsler performed the first corneal transplantation at the Zurich Eye clinic. Marc Amsler Marc Amsler

pos: Ron Gallemore public lectures and appearances. In 2007 he founded the Retina Macula Institute where he is currently the principal doctor and surgeon. Gallemore has published 60 peer-reviewed articles listed in Web of Science. His most cited has been the phase II multi-center study, "Verteporfin therapy of subfoveal minimally classic choroidal neovascularization in age-related macular degeneration – 2-year results of a randomized clinical trial." by Greve, MDJ; Hinz, BJ; Schulha, M, et al. "Archives of Ophthalmology" 123 (4): 448–457 (2005), Cited 70 times as of June 2009. Other highly cited papers include: Ron Gallemore Ron P. Gallemore is a registered ophthalmologist with

pos: Blue cone monochromacy Blue cone monochromacy Blue cone monochromacy (BCM) is an inherited eye disease that causes severely impaired color discrimination, low vision, nystagmus and photophobia due to the absence of functionality of red (L) and green (M) cone photoreceptor cells in the retina. This form of retinal disorder is a recessive X-linked disease and manifests its symptoms in early infancy. Blue cone monochromacy is considered a stationary (non-progressive) disease, although there is evidence of disease progression with macular degeneration in many patients. Cone photoreceptor cells in the retina are responsible for day-light vision, color vision, visual acuity and sight in the central

pos: Geographic atrophy Geographic atrophy Geographic atrophy (GA), also known as atrophic age-related macular degeneration (AMD) or advanced dry AMD, is an advanced form of age-related macular degeneration that can result in the progressive and irreversible loss of retina (photoreceptors, retinal pigment epithelium, choriocappillaris) which can lead to a loss of visual function over time. It is estimated that GA affects >5 million people worldwide and approximately 1 million patients in the US, which is similar to the prevalence of neovascular (wet) AMD, the other advanced form of the disease. The incidence of advanced AMD, both geographic atrophy and neovascular AMD, increases exponentially

pos: Macular degeneration are all genetic disorders that may occur in childhood or middle age. Similar symptoms with a very different etiology and different treatment can be caused by epiretinal membrane or macular pucker or any other condition affecting the macula, such as central serous retinopathy. Macular degeneration Macular degeneration, also known as age-related macular degeneration (AMD or ARMD), is a medical condition which may result in blurred or no vision in the center of the visual field. Early on there are often no symptoms. Over time, however, some people experience a gradual worsening of vision that may affect one or both eyes.

pos: Gene therapy of the human retina ability to target cone photoreceptors. The vertebrate neural retina composed of several layers and distinct cell types (see anatomy of the human retina). A number of these cell types are implicated in retinal diseases, including retinal ganglion cells, which degenerate in glaucoma, the rod and cone photoreceptors, which are responsive to light and degenerate in retinitis pigmentosa, macular degeneration, and other retinal diseases, and the retinal pigment epithelium (RPE), which supports the photoreceptors and is also implicated in retinitis pigmentosa and macular degeneration. In retinal gene therapy, AAV is capable of "transducing" these various cell types by entering the cells

pos: Retinal implant Retinal implant Retinal prostheses for restoration of sight to patients blinded by retinal degeneration are being developed by a number of private companies and research institutions worldwide. The system is meant to partially restore useful vision to people who have lost their photoreceptors due to retinal diseases such as retinitis pigmentosa (RP) or age-related macular degeneration (AMD). Three types of retinal implants are currently in clinical trials: epiretinal (on the retina), subretinal (behind the retina), and suprachoroidal (between the choroid and the sclera). Retinal implants introduce visual information into the retina by electrically stimulating the surviving retinal neurons. So far,

pos: Lawrence Yannuzzi director of The Retinal Research Center of the Manhattan Eye, Ear & Throat Hospital, and founder and president of The Macula Foundation. Yannuzzi has published more than 550 scientific papers and 12 textbooks, with particular concentration in diseases of the macula such as diabetic retinopathy and age-related macular degeneration. He is on the Board of Directors for Lighthouse International, a non-profit organization that does work in vision rehabilitation services, education, research, prevention and advocacy. Yannuzzi is a pioneer in angiography. He and his colleagues are credited as describing and coining the term "idiopathic polypoidal choroidal vasculopathy", a particular type of

pos: Peripherin 2 disk morphogenesis. Defects in this gene are associated with both central and peripheral retinal degenerations. Some of the various phenotypically different disorders are autosomal dominant retinitis pigmentosa, progressive macular degeneration, macular dystrophy and retinitis pigmentosa digenic. Peripherin 2 Peripherin-2 is a protein, that in humans is encoded by the "PRPH2" gene. Peripherin-2 is found in the rod and cone cells of the retina of the eye. Defects in this protein result in one form of retinitis pigmentosa, an incurable blindness. Mutations in the PRPH2 gene are associated with Vitelliform macular dystrophy. The protein encoded by this gene is a member

pos: Meso-zeaxanthin short-wavelength light incident at the macula causes chromatic aberration and light scatter, phenomena that adversely impact on visual function and result in poor contrast sensitivity. "Meso"-zeaxanthin is in the ideal location and has the ideal antioxidant and light-filtering properties to protect the macula and enhance visual performance. In 2013, the Age-Related Eye Disease Study 2 (AREDS2) reported a reduced risk of visual loss and a reduced risk of disease progression in patients with non-advanced age-related macular degeneration (AMD, the leading cause of blindness in the Western World; Taylor and Keeffe, 2001) who were supplemented with a formulation containing the macular

pos: Augmented reality is scanned directly onto the retina of a viewer's eye. This results in bright images with high resolution and high contrast. The viewer sees what appears to be a conventional display floating in space. Several of tests were done in order to analyze the safety of the VRD. In one test, patients with partial loss of vision were selected to view images using the technology having either macular degeneration (a disease that degenerates the retina) or keratoconus. In the macular degeneration group, 5 out of 8 subjects preferred the VRD images to the CRT or paper images and thought they

neg: Macula of retina Macula of retina The macula or macula lutea is an oval-shaped pigmented area near the center of the retina of the human eye and some other animalian eyes. The macula in humans has a diameter of around and is subdivided into the umbo, foveola, foveal avascular zone, fovea, parafovea, and perifovea areas. The anatomical macula at is much larger than the clinical macula which, at , corresponds to the anatomical fovea. The macula is responsible for the central, high-resolution, color vision that is possible in good light; and this kind of vision is impaired if the macula is damaged, for

neg: Macula of retina in representing the type of damage mediated by an infarct, in this case, indicating that the caudal visual cortex (which is the principal recipient of macular projections of the optic nerve) has been spared. Further, it indicates that cortical damage rostral to, and including, lateral geniculate nucleus is an unlikely outcome of the infarction, as too much of the lateral geniculate nucleus is, proportionally, devoted to macular-stream processing. Macula of retina The macula or macula lutea is an oval-shaped pigmented area near the center of the retina of the human eye and some other animalian eyes. The macula in humans

neg: Corpus luteum causes the degeneration of the corpus luteum and the abortion of the fetus. However, in placental animals such as humans, the placenta eventually takes over progesterone production and the corpus luteum degrades into a corpus albicans without embryo/fetus loss. Luteal support refers to the administration of medication (generally progestins) for the purpose of increasing the success of implantation and early embryogenesis, thereby complementing the function of the corpus luteum. The yellow color and name of the corpus luteum, like that of the macula lutea of the retina, is due to its concentration of certain carotenoids, especially lutein. In 1968, a

neg: Retina rods. In total, there are about seven million cones and a hundred million rods. At the centre of the macula is the foveal pit where the cones are narrow and long, and, arranged in a hexagonal mosaic, the most dense. At the foveal pit the other retinal layers are displaced, before building up along the foveal slope until the rim of the fovea, or parafovea, is reached, which is the thickest portion of the retina. The macula has a yellow pigmentation, from screening pigments, and is known as the macula lutea. The area directly surrounding the fovea has the highest

neg: Macular degeneration its function. Other gene markers of progression risk includes tissue inhibitor of metalloproteinase 3 (TIMP3), suggesting a role for extracellular matrix metabolism in AMD progression. Variations in cholesterol metabolising genes such as the hepatic lipase, cholesterol ester transferase, lipoprotein lipase and the ATP-binding cassette A1 correlate with disease progression. The early stigmata of disease, drusen, are rich in cholesterol, offering face validity to the results of genome-wide association studies. In AMD there is a progressive accumulation of characteristic yellow deposits, called drusen (buildup of extracellular proteins and lipids), in the macula (a part of the retina), between the retinal pigment

neg: Vitelliform macular dystrophy Vitelliform macular dystrophy Vitelliform macular dystrophy or vitelliform dystrophy is an irregular autosomal dominant eye disorder which can cause progressive vision loss. This disorder affects the retina, specifically cells in a small area near the center of the retina called the macula. The macula is responsible for sharp central vision, which is needed for detailed tasks such as reading, driving, and recognizing faces. The condition is characterized by yellow (or orange), slightly elevated, round structures similar to the yolk (Latin "vitellus") of an egg. "Best disease" is inherited in an autosomal dominant pattern, which means one copy of the altered

neg: Macular degeneration epithelium and the underlying choroid which is believed to damage the retina over time. Amyloid beta, which builds up in Alzheimer's disease brains, is one of the proteins that accumulate in AMD, which is a reason why AMD is sometimes called "Alzheimer's of the eye" or "Alzheimer's of the retina". AMD can be divided into 3 stages: early, intermediate, and late, based partially on the extent (size and number) of drusen. AMD-like pathology begins with small yellow deposits (drusen) in the macula, between the retinal pigment epithelium and the underlying choroid. Most people with these early changes (referred to as

neg: Lattice degeneration retinal detachment can occur. There are documented cases with macula-off retinal detachment in patients with asymptomatic lattice degeneration. Partial or complete vision loss almost always occurs in such cases. Currently there is no prevention or cure for lattice degeneration. Lattice degeneration Lattice degeneration is a disease of the human eye wherein the peripheral retina becomes atrophic in a lattice pattern and may develop tears, breaks, or holes, which may further progress to retinal detachment. It is an important cause of retinal detachment in young myopic individuals. The cause is unknown, but pathology reveals inadequate blood flow resulting in ischemia and

neg: Fovea centralis Fovea centralis The fovea centralis is a small, central pit composed of closely packed cones in the eye. It is located in the center of the macula lutea of the retina. The fovea is responsible for sharp central vision (also called foveal vision), which is necessary in humans for activities where visual detail is of primary importance, such as reading and driving. The fovea is surrounded by the "parafovea" belt, and the "perifovea" outer region. The parafovea is the intermediate belt, where the ganglion cell layer is composed of more than five rows of cells, as well as the highest

neg: Usher syndrome caused by a defective inner ear, whereas the vision loss results from retinitis pigmentosa (RP), a degeneration of the retinal cells. Usually, the rod cells of the retina are affected first, leading to early night blindness (nyctalopia) and the gradual loss of peripheral vision. In other cases, early degeneration of the cone cells in the macula occurs, leading to a loss of central acuity. In some cases, the foveal vision is spared, leading to "doughnut vision"; central and peripheral vision are intact, but an annulus exists around the central region in which vision is impaired. Although Usher syndrome has been

neg: Usher syndrome pigmentosa. The photoreceptor cells usually start to degenerate from the outer periphery to the center of the retina, including the macula. The degeneration is usually first noticed as night blindness (nyctalopia); peripheral vision is gradually lost, restricting the visual field (tunnel vision), which generally progresses to complete blindness. The qualifier "pigmentosa" reflects the fact that clumps of pigment may be visible by an ophthalmoscope in advanced stages of degeneration. The hearing impairment associated with Usher syndrome is caused by damaged hair cells in the cochlea of the inner ear inhibiting electrical impulses from reaching the brain. Since Usher syndrome is

neg: Parafovea presented parafoveally. Parafovea Parafovea or the parafoveal belt is a region in the retina that circumscribes the fovea and is part of the macula lutea. It is circumscribed by the perifovea. In reading, information within 1° (approximately 6–8 characters) of the point of fixation is processed in foveal vision, while information up to 6° of visual angle benefits from parafoveal preview. Studies have shown that people can tell the difference in the letters of a word in the fovea and near-parafovea (the part of the parafovea closest to the fovea), but not in the outer edges of the parafovea. In

neg: Parafovea Parafovea Parafovea or the parafoveal belt is a region in the retina that circumscribes the fovea and is part of the macula lutea. It is circumscribed by the perifovea. In reading, information within 1° (approximately 6–8 characters) of the point of fixation is processed in foveal vision, while information up to 6° of visual angle benefits from parafoveal preview. Studies have shown that people can tell the difference in the letters of a word in the fovea and near-parafovea (the part of the parafovea closest to the fovea), but not in the outer edges of the parafovea. In languages that

neg: Vitelliform macular dystrophy cells in the retina. Mutations in the "VMD2" gene probably lead to the production of an abnormally shaped channel that cannot regulate the flow of chloride. Researchers have not determined how these malfunctioning channels are related to the buildup of lipofuscin in the macula and progressive vision loss. The "RDS" gene provides instructions for making a protein called peripherin. This protein is essential for the normal function of light-sensing (photoreceptor) cells in the retina. Mutations in the RDS gene disrupt the structures in these cells that contain light-sensing pigments, leading to vision loss. It is unclear why RDS mutations affect

neg: Briard is also commonly screened for congenital stationary night blindness (SNB) with a DNA test. SNB is inherited through recessive genes. Progressive retinal atrophy PRA, is a disease that causes nerve cells at the back of the eye to degenerate. The condition usually begins in older pets and can lead to blindness. Progressive retinal degeneration or atrophy (PRD/PRA) represents a group of inherited eye diseases characterized by abnormal development or premature degeneration of the retina. There are two types of photoreceptors in the retina and these are the light-sensitive rods and cones. They are responsible for detecting light and converting it

neg: Xanthophyll and in dietary animal products, are ultimately derived from plant sources in the diet. For example, the yellow color of chicken egg yolks, fat, and skin comes from ingested xanthophylls (primarily lutein, which is often added to chicken feed for this purpose). The yellow color of the human macula lutea (literally, "yellow spot") in the retina of the eye results from the lutein and zeaxanthin it contains, both xanthophylls again requiring a source in the human diet to be present in the eye. These xanthophylls protect the eye from ionizing blue and ultraviolet light, which they absorb. These two specific

neg: Ganglion cell layer Ganglion cell layer The ganglion cell layer (ganglionic layer) is a layer of the retina that consists of retinal ganglion cells and displaced amacrine cells. In the macula lutea, the layer forms several strata. The cells are somewhat flask-shaped; the rounded internal surface of each resting on the stratum opticum, and sending off an axon which is prolonged into it. From the opposite end numerous dendrites extend into the inner plexiform layer, where they branch and form flattened arborizations at different levels. The ganglion cells vary much in size, and the dendrites of the smaller ones as a rule arborize

neg: Ganglion cell layer in the inner plexiform layer as soon as they enter it; while those of the larger cells ramify close to the inner nuclear layer. Ganglion cell layer The ganglion cell layer (ganglionic layer) is a layer of the retina that consists of retinal ganglion cells and displaced amacrine cells. In the macula lutea, the layer forms several strata. The cells are somewhat flask-shaped; the rounded internal surface of each resting on the stratum opticum, and sending off an axon which is prolonged into it. From the opposite end numerous dendrites extend into the inner plexiform layer, where they branch and

neg: Meso-zeaxanthin Meso-zeaxanthin "Meso"-zeaxanthin (3R,3´S-zeaxanthin) is a xanthophyll carotenoid, as it contains oxygen and hydrocarbons, and is one of the three stereoisomers of zeaxanthin. Of the three stereoisomers, "meso"-zeaxanthin is the second most abundant in nature after 3R,3´R-zeaxanthin, which is produced by plants and algae. To date, "meso"-zeaxanthin has been identified in specific tissues of marine organisms and in the macula lutea, also known as the "yellow spot", of the human retina. Carotenoids are essential for animal life, but animals cannot produce them. Indeed, animals obtain carotenoids from diet, with herbivores sourcing them from plants or algae, and carnivores, in turn, sourcing

neg: Sudden acquired retinal degeneration syndrome few months atrophy of the retina will resemble the appearance of progressive retinal atrophy. Pathologically, there is a loss of the rod and cone cells followed by degeneration of other layers of the retina. The retinal degeneration appears to be related to apoptosis of these cells. SARDS must be distinguished from other causes of sudden blindness that have no visible pathology, including retrobulbar optic neuritis, a tumor at the optic chiasm, or other central nervous system diseases. Electroretinography is useful to definitively diagnose SARDS. As of 2016, there is no effective treatment for SARDS. Various immunosuppressive treatment regimens have been

neg: Macular degeneration typically occurs in older people. Genetic factors and smoking also play a role. It is due to damage to the macula of the retina. Diagnosis is by a complete eye exam. The severity is divided into early, intermediate, and late types. The late type is additionally divided into "dry" and "wet" forms with the dry form making up 90% of cases. Preventive efforts include exercising, eating well, and not smoking. Antioxidant vitamins and minerals do not appear to be useful for prevention. There is no cure or treatment that returns vision already lost. In the wet form, anti-VEGF medication injected

neg: Macula of retina is seen when viewed from the pupil, as in ophthalmoscopy or retinal photography. The anatomical macula is defined histologically in terms of having two or more layers of ganglion cells. The umbo is the center of the foveola which in turn is located at the center of the fovea. The fovea is located near the center of the macula. It is a small pit that contains the largest concentration of cone cells. The retina contains two types of photosensitive cells, the rod cells and the cone cells. Because the macula is yellow in colour it absorbs excess blue and ultraviolet

neg: Adaptation (eye) takes for the eye to adapt from bright light to darkness. This RI number provides a clear and objective measurement of retinal function with 90% sensitivity and specificity. Basically, an RI of less than 6.5 minutes indicates a healthy dark adaptation function. However, an RI higher than 6.5 indicates impaired dark adaptation. Numerous clinical studies have shown that dark adaptation function is dramatically impaired from the earliest stages of AMD, retinitis pigmentosa (RP), and other retinal diseases, with increasing impairment as the diseases progress. AMD is a chronic, progressive disease that causes a part of your retina, called the macula,

neg: Retinal degeneration (rhodopsin mutation) non-rhodopsin mutations may also be critical in presentation of retinal degenerative disorders. It suggests a mechanism for retinal degeneration caused by non-retinal-specific genes, such as PRPF31 mutations. Retinal degeneration (rhodopsin mutation) Retinal degeneration is a retinopathy which consists in the deterioration of the retina caused by the progressive death of its cells. There are several reasons for retinal degeneration, including artery or vein occlusion, diabetic retinopathy, R.L.F./R.O.P. (retrolental fibroplasia/ retinopathy of prematurity), or disease (usually hereditary). These may present in many different ways such as impaired vision, night blindness, retinal detachment, light sensitivity, tunnel vision, and loss of peripheral vision

neg: Macular hole slowly shrinks on its own. Treatment is also done using ocriplasmin. Macular hole A macular hole is a small break in the macula, located in the center of the eye's light-sensitive tissue called the retina. If the vitreous is firmly attached to the retina when it pulls away, it can tear the retina and create a macular hole. Also, once the vitreous has pulled away from the surface of the retina, some of the fibers can remain on the retinal surface and can contract. This increases tension on the retina and can lead to a macular hole. In either case,

neg: Macular degeneration "wet" form of advanced AMD, causes vision loss due to abnormal blood vessel growth (choroidal neovascularization) in the choriocapillaris, through Bruch's membrane. It is usually, but not always, preceded by the dry form of AMD. The proliferation of abnormal blood vessels in the retina is stimulated by vascular endothelial growth factor (VEGF). Unfortunately, because these blood vessels are abnormal, these new vessels are fragile, ultimately leading to blood and protein leakage below the macula. Bleeding, leaking, and scarring from these blood vessels eventually cause irreversible damage to the photoreceptors and rapid vision loss if left untreated. Age-related accumulation of low-molecular-weight,

neg: Macular hole Macular hole A macular hole is a small break in the macula, located in the center of the eye's light-sensitive tissue called the retina. If the vitreous is firmly attached to the retina when it pulls away, it can tear the retina and create a macular hole. Also, once the vitreous has pulled away from the surface of the retina, some of the fibers can remain on the retinal surface and can contract. This increases tension on the retina and can lead to a macular hole. In either case, the fluid that has replaced the shrunken vitreous can then seep

neg: Retinal degeneration (rhodopsin mutation) Retinal degeneration (rhodopsin mutation) Retinal degeneration is a retinopathy which consists in the deterioration of the retina caused by the progressive death of its cells. There are several reasons for retinal degeneration, including artery or vein occlusion, diabetic retinopathy, R.L.F./R.O.P. (retrolental fibroplasia/ retinopathy of prematurity), or disease (usually hereditary). These may present in many different ways such as impaired vision, night blindness, retinal detachment, light sensitivity, tunnel vision, and loss of peripheral vision to total loss of vision. Of the retinal degenerative diseases retinitis pigmentosa (RP) is a very important example. Inherited retinal degenerative disorders in humans exhibit genetic and

neg: Diabetic retinopathy any change in their vision. Early changes that are reversible and do not threaten central vision are sometimes termed "simplex retinopathy" or "background retinopathy". Some people develop a condition called macular edema. It occurs when the damaged blood vessels leak fluid and lipids onto the macula, the part of the retina that lets us see detail. The fluid makes the macula swell, which blurs vision. As the disease progresses, severe nonproliferative diabetic retinopathy enters an advanced or proliferative (PDR) stage, where blood vessels proliferate/grow. The lack of oxygen in the retina causes fragile, new, blood vessels to grow along the

neg: Vitrectomy eye, and injection of a gas or silicone oil to secure the retina in place as it heals. Macular pucker – formation of a patch of unhealthy tissue in the central retina (the macula) distorting vision. Also called epiretinal membrane. After vitrectomy to remove the vitreous gel, membranectomy is undertaken to peel away the tissue. Diabetic retinopathy – may damage sight by either a non-proliferative or proliferative retinopathy. The proliferative type is characterized by formation of new unhealthy, freely bleeding blood vessels within the eye (called vitreal hemorrhage) and/or causing thick fibrous scar tissue to grow on the retina, detaching

neg: Ophrys lutea time (May 2014) the following are accepted: March to May Grows in full sun or shade on limey dry or damp soils, pastures, and thin woodland. "" Ophrys lutea Ophrys lutea, the yellow bee-orchid, is a species of orchid native to southern Europe, North Africa, and the Middle East, the range extending from Portugal and Morocco to Syria. Broad asymmetric lateral sepals, dorsal sepal lowered. Extended petals, yellow or with a blue-grey or brown spotted velvety macula. Pollinated by male "Andrena" bees. This species is notable among "Ophrys" for the fact that the pollinating bees sit on the labellum facing

neg: Retina entire retina contains about 7 million cones and 75 to 150 million rods. The optic disc, a part of the retina sometimes called "the blind spot" because it lacks photoreceptors, is located at the optic papilla, where the optic-nerve fibres leave the eye. It appears as an oval white area of 3 mm². Temporal (in the direction of the temples) to this disc is the macula, at whose centre is the fovea, a pit that is responsible for our sharp central vision but is actually less sensitive to light because of its lack of rods. Human and non-human primates possess

neg: Ophrys lutea Ophrys lutea Ophrys lutea, the yellow bee-orchid, is a species of orchid native to southern Europe, North Africa, and the Middle East, the range extending from Portugal and Morocco to Syria. Broad asymmetric lateral sepals, dorsal sepal lowered. Extended petals, yellow or with a blue-grey or brown spotted velvety macula. Pollinated by male "Andrena" bees. This species is notable among "Ophrys" for the fact that the pollinating bees sit on the labellum facing away from the pollinaria instead of facing towards them, and thus collect the pollinaria with their abdomen. Numerous subspecific names have been proposed, but at the present

neg: Progressive retinal atrophy symptoms, and it is also possible for onset of the disease to be later than expected, making this an imperfect test at best. Progressive retinal atrophy Progressive retinal atrophy (PRA) is a group of genetic diseases seen in certain breeds of dogs and, more rarely, cats. Similar to retinitis pigmentosa in humans, it is characterized by the bilateral degeneration of the retina, causing progressive vision loss culminating in blindness. The condition in nearly all breeds is inherited as an autosomal recessive trait, with the exception of the Siberian Husky (inherited as an X chromosome linked trait) and the Bullmastiff (inherited

neg: Progressive retinal atrophy Progressive retinal atrophy Progressive retinal atrophy (PRA) is a group of genetic diseases seen in certain breeds of dogs and, more rarely, cats. Similar to retinitis pigmentosa in humans, it is characterized by the bilateral degeneration of the retina, causing progressive vision loss culminating in blindness. The condition in nearly all breeds is inherited as an autosomal recessive trait, with the exception of the Siberian Husky (inherited as an X chromosome linked trait) and the Bullmastiff (inherited as an autosomal dominant trait). There is no treatment. In general, PRAs are characterised by initial loss of rod photoreceptor cell function followed

neg: Peripheral vision the retina tend to be irregular ovals. Thus, foveal vision may also be defined as the central 1.5–2° of the field of vision. Vision within the fovea is generally called central vision, while vision outside of the fovea is called peripheral, or indirect vision. A ring-shaped region surrounding the fovea, known as the parafovea, is sometimes taken to represent an intermediate form of vision called paracentral vision. The parafovea has an outer diameter of 2.5 mm representing 8° of the field of vision. The macula, a region of the retina defined as having at least two layers of ganglia (bundles

neg: History of Tay–Sachs disease an exclusively Jewish disease, because most of the cases at first reported were between Russian and Polish Jews; but recently there have been reported cases occurring in non-Jewish children. The chief characteristics of the disease are progressive mental and physical enfeeblement; weakness and paralysis of all the extremities; and marasmus, associated with symmetrical changes in the macula lutea. On investigation of the reported cases, they found that neither consanguinity nor syphilitic, alcoholic, or nervous antecedents in the family history are factors in the etiology of the disease. No preventive measures have as yet been discovered, and no treatment has been

neg: Diabetic retinopathy protects the retina from many substances in the blood (including toxins and immune cells), leading to the leaking of blood constituents into the retinal neuropile. Later, the basement membrane of the retinal blood vessels thickens, capillaries degenerate and lose cells, particularly pericytes and vascular smooth muscle cells. This leads to loss of blood flow and progressive ischemia, and microscopic aneurysms which appear as balloon-like structures jutting out from the capillary walls, which recruit inflammatory cells; and advanced dysfunction and degeneration of the neurons and glial cells of the retina. An experimental study suggests that pericyte death is caused by blood

neg: Foveola Foveola The foveola is located within a region called the macula, a yellowish, cone photo receptor filled portion of the human retina. The foveola is approximately 0.35 mm in diameter and lies in the center of the fovea and contains only cone cells, and a cone-shaped zone of Müller cells. In this region the cone receptors are found to be longer, slimmer and more densely packed than anywhere else in the retina, thus allowing that region to have the potential to have the highest visual acuity in the eye. The centre of the foveola is sometimes referred to as the

neg: Conorenal syndrome no known cures for the syndrome and management of the symptoms seems to be the typical approach. The syndrome was originally characterized during 1970 by Mainzer, et al., in a paper published in the American Journal of Medicine. In 1979, Giedion named the syndrome "conorenal syndrome" after a study of eight children. The children had chronic renal failure and the epiphyses of their fingers were cone-shaped and protruded into the metaphysis; some also had retinitis pigmentosa (also called RP, a progressive degeneration of the retina which affects night vision and peripheral vision) or ataxia (an inability to coordinate muscular movements).

neg: Central retinal artery Central retinal artery The central retinal artery (retinal artery) branches off the ophthalmic artery, running inferior to the optic nerve within its dural sheath to the eyeball. It pierces the eyeball close to the optic nerve, sending branches over the internal surface of the retina, and these terminal branches are the only blood supply to the larger part of it. The central part of the retina where the light rays are focussed after passing through the pupil and the lens is a circular area called the macula. The center of this circular area is the fovea. The fovea and a

neg: Macula of retina shown to prevent the disease. After death or enucleation (removal of the eye) the macula appears yellow, a color that is not visible in the living eye except when viewed with light from which red has been filtered. Structures in the macula are specialized for high-acuity vision. Within the macula are the fovea and foveola that both contain a high density of cones, which are nerve cells that are photoreceptors with high acuity. In details, the normal human eye contains three different types of cones, with different ranges of spectral sensitivity. The brain combines the signals from neighboring cones to

neg: Disc shedding Disc shedding Disc shedding is the process by which photoreceptors in the eye are renewed. The retina contains two types of photoreceptor – rod cells and cone cells. There are about 6-7 million cones that provide color vision to the eye, and they are very concentrated in a central spot in the retina, called the macula. However, the rods are much more numerous – about 120 million – and are also more sensitive than the cones. These rods are responsible for scotopic (night) vision, our most sensitive motion detection, and our peripheral vision. Vertebrate photoreceptors are composed of a photosensitive

neg: Rough Collie development of the eye and possible blindness, is a common ailment in the breed. More rarely, Rough Collies can be affected by progressive retinal atrophy (PRA), another genetic disease in which bilateral degeneration of the retina results in progressive vision loss culminating in blindness. Through genetic testing and careful screening program it would be theoretically possible to eradicate both of these problems in purebred lines, however, certainly in the UK, the Kennel Club does not require these tests to be done either for registration or showing. CEA is so prevalent that elimination of affected dogs except through very slow and

neg: Retina one fovea, as opposed to certain bird species, such as hawks, who are bifoviate, and dogs and cats, who possess no fovea but a central band known as the visual streak. Around the fovea extends the central retina for about 6 mm and then the peripheral retina. The farthest edge of the retina is defined by the ora serrata. The distance from one ora to the other (or macula), the most sensitive area along the horizontal meridian is about 32 mm. In section, the retina is no more than 0.5 mm thick. It has three layers of nerve cells and

neg: Australian Cattle Dog be deaf in both ears and 14.5% were deaf in at least one ear. The Australian Cattle Dog is one of the dog breeds affected by progressive retinal atrophy. It has the most common form, progressive rod-cone degeneration (PRCD), a condition that causes the rods and cones in the retina of the eye to deteriorate later in life, resulting in blindness. PRCD is an autosomal recessive trait and a dog can be a carrier of the affected gene without developing the condition. Hip dysplasia is not common in the breed, although it occurs sufficiently often for many breeders to have

neg: Meso-zeaxanthin addition, in some of the formulations tested, it was found that "meso"-zeaxanthin was present in the formulation, even though this carotenoid was not declared on the supplement product labels. The authors concluded that the presence of "meso"-zeaxanthin in these formulations was likely due to the process used to extract lutein from the marigold petal. "Meso"-zeaxanthin, lutein, and 3R,3´R-zeaxanthin are the main carotenoids in the macula lutea, found in a ratio of 1:1:1, and are collectively referred to as macular pigment (MP). "Meso"-zeaxanthin is concentrated at the epicentre of the macula, where it accounts for around 50% of MP at this

neg: Lutein absorbed from blood specifically into the macula lutea, although its precise role in the body is unknown. Lutein is also found in egg yolks and animal fats. Lutein is isomeric with zeaxanthin, differing only in the placement of one double bond. Lutein and zeaxanthin can be interconverted in the body through an intermediate called "meso"-zeaxanthin. The principal natural stereoisomer of lutein is -"beta","epsilon"-carotene-3,3′-diol. Lutein is a lipophilic molecule and is generally insoluble in water. The presence of the long chromophore of conjugated double bonds (polyene chain) provides the distinctive light-absorbing properties. The polyene chain is susceptible to oxidative degradation by

neg: Nova Scotia Duck Tolling Retriever tend to be immunity related. They can be affected by eye problems and hip dysplasia and are predisposed to immune-mediated rheumatic disease and steroid-responsive meningitis–arthritis. Progressive retinal atrophy (PRA) affects about 7% of Tollers with an estimated 40% being carriers. The type of PRA associated with the breed is known as progressive rod-cone degeneration. The disease causes cells in the retina to degenerate and die. This causes night blindness at first and eventually complete blindness. Collie eye anomaly is estimated to have a carrier rate of 5% and an affected rate of 0.5%. It generally only causes mildly impaired vision,

neg: Posterior vitreous detachment the retina anteriorly, at a structure called the vitreous base. The membrane does not normally detach from the vitreous base, although it can be detached with extreme trauma. However, the vitreous base may have an irregular posterior edge. When the edge is irregular, the forces of the vitreous membrane peeling off the retina can become concentrated at small posterior extensions of the vitreous base. Similarly, in some people with retinal lesions such as lattice retinal degeneration or chorio-retinal scars, the vitreous membrane may be abnormally adherent to the retina. If enough traction occurs the retina may tear at these points.

neg: Haidinger's brush with the visual field of the macula means that it can be utilised in training people to look at objects with their macula. People with certain types of strabismus may undergo an adaptation whereupon they look at the object of attention not with their fovea (at the centre of the macula) but with an eccentric region of the retina. This adaptation is known as eccentric fixation. To aid in training a person to look at an object with their fovea rather than their eccentric retinal zone, a training device can be used. One such apparatus utilises a rotating polarised plate

neg: Macula of retina As a result, some forms of visual field loss that occur without involving the macula are termed macular sparing. (For example, visual field testing might demonstrate "homonymous hemianopsia with macular sparing".) In the case of occipitoparietal ischemia owing to occlusion of elements of either posterior cerebral artery, patients may display cortical blindness (which, rarely, can involve blindness that the patient denies having, as seen in Anton's Syndrome), yet display sparing of the macula. This selective sparing is due to the collateral circulation offered to macular tracts by the middle cerebral artery. Neurological examination that confirms macular sparing can go far

neg: Macular degeneration blood vessels (neovascularization) result in the death of photoreceptors and central vision loss. In the dry (nonexudative) form, cellular debris called drusen accumulates between the retina and the choroid, causing atrophy and scarring to the retina. In the wet (exudative) form, which is more severe, blood vessels grow up from the choroid (neovascularization) behind the retina which can leak exudate and fluid and also cause hemorrhaging. Early work demonstrated a family of immune mediators was plentiful in drusen. Complement factor H (CFH) is an important inhibitor of this inflammatory cascade, and a disease-associated polymorphism in the CFH gene strongly associates

neg: Lattice degeneration an increased risk of retinal detachment. Risk of developing lattice degeneration in one eye is also increased if lattice degeneration is already present in the other eye. "Typical lattice" consists of sharply demarcated, spindle-shaped areas of retinal thinning, usually located between the equator of the retina and the posterior border of the vitreous base. This is more frequently located in the temporal half of the retina and is seen more superiorly than inferiorly. "Atypical lattice" is characterised by radial lesions which appear continuous with the peripheral blood vessels. This type is typically seen in patients with Stickler syndrome. Barrage laser

neg: Steve Charles (surgeon) as lectured extensively in the field. He is the author of one of the leading textbooks in the field along with nearly 200 scholarly publications. He is the founder of the Charles Retina Institute, located in Memphis, Tennessee, which is an eye clinic specializing in the treatment of retina, macula, and vitreous diseases. He is a Fellow in the American College of Surgeons and International College of Surgeons and a member of the Retina Society, Macular Society, American Society of Retinal Specialists, Club Jules Gonin, American Society of Cataract and Refractive Surgery, American Academy of Ophthalmology, American-European College of Ophthalmic

neg: Balinese cat disease for Balinese is Progressive Retinal Atrophy(PRA), which is a degeneration of the retina in the eye; which may lead to weak or impaired vision. There has been some cases of Balinese having dilated cardiomyopathy, which is a disease that enlarges the heart muscles that decreases heart function. There are also some claims that they are at a low risk for hypertrophic cardiomyopathy (HCM). Another potential health problem is liver amyloidosis, or systemic amyloidosis which eventually leads to failure of some organ, most commonly the liver. Liver amyloidosis typically occurs in any members of the Siamese and the Balinese is

neg: Progressive retinal atrophy chromosome. This condition is linked to the X chromosome. CPRA is also known as retinal pigment epithelial dystrophy (RPED). The cause of this condition is the loss of the retinal pigment epithelium's ability to effectively process the photoreceptor outer segment (POS) and subsequent accumulation of POS material in the RPE and loss of function. The loss of function of the RPE leads to photoreceptor degeneration. Vitamin E deficiency may play a role in the development of CPRA. It is characterized by accumulation of pigment spots in the retina surrounded by retinal atrophy and a mottled appearance of the pigmented nontapetal

neg: Basenji dysplasia, resulting in loss of mobility and arthritis-like symptoms. All dogs should be tested by either OFA or PennHIP prior to breeding. Malabsorption, or immunoproliferative enteropathy, is an autoimmune intestinal disease that leads to anorexia, chronic diarrhea, and even death. A special diet can improve the quality of life for afflicted dogs. The breed can also fall victim to progressive retinal atrophy (a degeneration of the retina causing blindness) and several less serious hereditary eye problems such as coloboma (a hole in the eye structure), and persistent pupillary membrane (tiny threads across the pupil). Basenji The Basenji is a breed

neg: Knobloch syndrome Knobloch syndrome Knobloch syndrome is a rare genetic disorder presenting severe eyesight problems and often a defect in the skull. It was named after the ophthalmologist William Hunter Knobloch (1926 - 2015), who first described the syndrome in 1971. A usual occurrence is a degeneration of the vitreous humour and the retina, two components of the eye. This breakdown often results in the separation of the retina (the light-sensitive tissue at the back of the eye) from the eye, called retinal detachment, which can be recurrent. Extreme myopia (near-sightedness) is a common feature. The limited evidence available from electroretinography suggests

neg: Distorted vision phenomenon, with the central vision being involved, or with the visual effect similar to "heat rising off of a car". Some people describe a "kaleidoscope" effect, with pieces of the vision being missing. All of these variations are consistent with ophthalmic migraine. Seeing rainbows around lights, especially at night, usually indicates swelling of the cornea. This may occur from a variety of causes which are discussed under Corneal Edema. Cataract can sometimes cause this also. Colour vision is perceived mainly by the macula, which is the central vision portion of the retina. Thus any disorder affecting the macula may cause

neg: MYO7A eukaryotic cells and are primarily thought to be involved in the movement or linkage of intra-cellular membranes and organelles to the actin cytoskeleton via interactions mediated by their highly divergent tail domains. MYO7A is expressed in a number of mammalian tissues, including testis, kidney, lung, inner ear, retina and the ciliated epithelium of the nasal mucosa. Mutations in the "MYO7A" gene cause the Usher syndrome type 1B, a combined deafness/blindness disorder. Affected individuals are typically profoundly deaf at birth and then undergo progressive retinal degeneration. Model organisms have been used in the study of MYO7A function. A spontaneous mutant mouse

neg: English Springer Spaniel have the chance. The English Springer Spaniel has a typical lifespan of 10.5 to 15 years. As in most breeds, there are some health problems that are more likely to occur. Hip dysplasia and progressive retinal atrophy (PRA) (a degeneration of the retina causing vision loss leading to blindness) are two such diseases for which veterinarians are working on genetic markers to determine carriers. Another problem can be elbow dysplasia. Retinal dysplasia (RD), which can cause blindness and Phosphofructokinase deficiency (PFK), which is genetic deficiency which impairs the ability of cells using carbohydrates for energy are two other hereditary conditions

neg: Inosine-5′-monophosphate dehydrogenase express two distinct isozymes of IMPDH encoded by two distinct genes, "IMPDH1" and "IMPDH2". Both isozymes contain 514 residues, have an 84% similarity in peptide sequence, and have similar kinetic properties. Both isozymes are constitutively expressed in most tissues, but "IMPDH1" is predominately expressed in the spleen, retina, and peripheral blood leukocytes. "IMPDH1" is generally expressed constitutively at low levels, and "IMPDH2" is generally upregulated in proliferating cells and neoplastic tissues. Homozygous "IMPDH1" knockout mice demonstrate a mild retinopathy in which a slow, progressive form of retinal degeneration gradually weakens visual transduction, while homozygous "IMPDH2" knockout mice display embryonic lethality.

neg: Vitreous body gel-like near the edges. The vitreous humour is in contact with the retina. Collagen fibrils attach the vitreous at the optic nerve disc and the ora serrata (where the retina ends anteriorly), at the Wieger-band, the dorsal side of the lens. The vitreous also firmly attaches to the lens capsule, retinal vessels, and the macula, the area of the retina which provides finer detail and central vision. Aquaporin-4 in Müller cell in rats transports water to the vitreous body. The vitreous has many anatomical landmarks, including the hyaloid membrane, Berger's space, space of Erggelet, Wieger's ligament, Cloquet's canal and the

neg: Macular edema Macular edema Macular edema occurs when fluid and protein deposits collect on or under the macula of the eye (a yellow central area of the retina) and causes it to thicken and swell (edema). The swelling may distort a person's central vision, because the macula holds tightly packed cones that provide sharp, clear, central vision to enable a person to see detail, form, and color that is directly in the centre of the field of view. The causes of macular edema are numerous and different causes may be inter-related. Cystoid macular edema (CME) involves fluid accumulation in the outer plexiform

neg: Macular edema eye can result in improved visual outcomes for patients with chronic or refractory diabetic macular edema. Macular edema Macular edema occurs when fluid and protein deposits collect on or under the macula of the eye (a yellow central area of the retina) and causes it to thicken and swell (edema). The swelling may distort a person's central vision, because the macula holds tightly packed cones that provide sharp, clear, central vision to enable a person to see detail, form, and color that is directly in the centre of the field of view. The causes of macular edema are numerous and

neg: Retinoschisis is not known to be a genetically inherited condition. There is always vision loss in the region of the schisis as the sensory retina is separated from the ganglion layer. But as the loss is in the periphery, it goes unnoticed. It is the very rare schisis that encroaches on the macula where retinopexy is then properly used. Hereditary retinoschisis is derived from a defective retinoschisin protein, which is due to an X-linked genetic defect. The genetic form of this disease usually starts during childhood and is called X-linked Juvenile Retinoschisis (XLRS) or Congenital Retinoschisis. Affected males are usually identified

neg: Chain mail One theory is that it originally derives from the Latin word, "macula", meaning "spot" or "opacity" (as in macula of retina). Another theory relates the word to the old French, "maillier", meaning "to hammer" (related to the modern English word, "malleable"). In modern French, "maille" refers to a loop or stitch. The Arabic words "burnus", برنوس, a burnoose; a hooded cloak, also a chasuble (worn by Coptic priests) and "barnaza", برنز, to bronze, suggest an Arabic influence for the Carolingian armour known as "byrnie" (see below). The first attestations of the word "mail" are in Old French and Anglo-Norman: "maille",

neg: Transneuronal degeneration Loss of sensory receptors in the cochlea, vestibules, and retina result in ganglion degeneration and transneuronal degeneration. Demyelination also results as oligodendrocytes and Schwann cells are killed. Evidence supports the theory that amyotorphic lateral sclerosis causes anterograde dengeneration of corticomotoneurons. The hyperexcitable corticomotoneurons drive anterior horn cells into metabolic deficit, resulting in cell degeneration and death. If this exocitotoxic process occurs rapidly, it results in a more rapid death of anterior horn cells resulting in lower motor neuron disease. There are several different mechanisms by which transneuronal degeneration can occur. The technical cause of transneuronal degeneration is the death of

neg: Lattice degeneration is at times done prophylactically around a hole or tear associated with lattice degeneration in an eye at risk of developing a retinal detachment. It is not known if surgical interventions such as laser photocoagulation or cryotherapy is effective in preventing retinal detachment in patients with lattice degeneration or "asymptomatic" retinal detachment. Laser photocoagulation has been shown to reduce risks of retinal detachment in "symptomatic" lattice degeneration. There are documented cases wherein retina detached from areas which were otherwise healthy despite being treated previously with laser. No complications are encountered in most patients with lattice degeneration, although in young myopes,

neg: Central retinal artery small area surrounding it are not supplied by the central retinal artery or its branches, but instead by the choroid. The central retinal artery is approximately 160 micrometres in diameter. In some cases - approximately 20% of the population - there is a branch of the ciliary circulation called the cilio-retinal artery which supplies the retina between the macula and the optic nerve, including the nerve fibers from the foveal photoreceptors. If this artery is present, the central vision will be preserved even in case of CRAO. The central retinal artery is formed from the proximal part of the hyaloid

neg: José-Alain Sahel on developmental biology, functional genomics, physiology and therapeutics (stem cells, gene therapy, pharmacology, artificial retina), research on relevant biomarkers and disease models. The common thread of his work is understanding and prevention of central vision loss through degeneration of photoreceptor cells (retinitis pigmentosa genetic) and age-related degeneration (AMD). One of the major discoveries made by José-Alain Sahel and his colleagues Thierry Léveillard and Saddek Mohand-Said is that the rod photoreceptors produce a trophic factor (called sustainability factor cones or RdCVF for Rod-derived Cone Viability Factor) which uses the cone photoreceptors to survive. This discovery provided the biological basis for paracrine

neg: Orthodenticle homeobox 2 role in development and if it is expressed incorrectly it can have detrimental effects on the fetus. Otx2 mutations have also been associated with seizures, developmental delays, short stature, structural abnormalities of the pituitary gland, and an early onset of degeneration of the retina. A “knockout” model on the group of Otx2 genes has been performed to see what effects it would have on the adult retina. It was found that without the Otx2 gene expression there was slow degeneration of photoreceptor cells in this area. Thus, proving that the homeobox genes of Otx2 are essential in forming a viable