|
Rhegmatogenous Retinal Detachment
Retinal detachment is a condition where the retina pulls away from the tissue underneath it. It may start in a small area, but without quick treatment, it can spread across the entire retina, leading to serious Visual impairment, vision loss and possibly blindness. Retinal detachment is a medical emergency that requires surgery. The retina is a thin layer at the back of the eye that processes visual information and sends it to the brain. When the retina detaches, common symptoms include seeing floaters, Photopsia, flashing lights, a dark shadow in vision, and sudden blurry vision. The most common type of retinal detachment is rhegmatogenous, which occurs when a tear or hole in the retina lets fluid from the center of the eye get behind it, causing the retina to pull away. Rhegmatogenous retinal detachment is most commonly caused by posterior vitreous detachment, a condition where the gel inside the eye breaks down and pulls on the retina. Risk factors include older age, nearsighted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retina
The retina (; or retinas) is the innermost, photosensitivity, light-sensitive layer of tissue (biology), tissue of the eye of most vertebrates and some Mollusca, molluscs. The optics of the eye create a focus (optics), focused two-dimensional image of the visual world on the retina, which then processes that image within the retina and sends nerve impulses along the optic nerve to the visual cortex to create visual perception. The retina serves a function which is in many ways analogous to that of the photographic film, film or image sensor in a camera. The neural retina consists of several layers of neurons interconnected by Chemical synapse, synapses and is supported by an outer layer of pigmented epithelial cells. The primary light-sensing cells in the retina are the photoreceptor cells, which are of two types: rod cell, rods and cone cell, cones. Rods function mainly in dim light and provide monochromatic vision. Cones function in well-lit conditions and are responsible fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macular Degeneration
Macular degeneration, also known as age-related macular degeneration (AMD or ARMD), is a medical condition which may result in blurred vision, blurred or vision loss, no vision in the center of the visual field. Early on there are often no symptoms. Some people experience a gradual worsening of vision that may affect one or both eyes. While it does not result in complete blindness, loss of central vision can make it hard to recognize faces, drive, read, or perform other activities of daily life. Visual release hallucinations, Visual hallucinations may also occur. Macular degeneration typically occurs in older people, and is caused by damage to the macula of retina, macula of the retina. Genetic factors and smoking may play a role. The condition is diagnosed through a complete eye exam. 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. The difference between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slit Lamp
In ophthalmology and optometry, a slit lamp is an instrument consisting of a high-intensity light source that can be focused to shine a thin sheet of light into the eye. It is used in conjunction with a biomicroscope. The lamp facilitates an examination of the anterior segment and posterior segment of the human eye, which includes the eyelid, sclera, conjunctiva, iris (anatomy), iris, natural crystalline lens, and cornea. The binocular slit-lamp examination provides a stereoscopic magnified view of the eye structures in detail, enabling anatomical diagnoses to be made for a variety of eye conditions. A second, hand-held lens is used to examine the retina. History Two conflicting trends emerged in the development of the slit lamp. One trend originated from clinical research and aimed to apply the increasingly complex and advanced technology of the time. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophthalmoscopy
Ophthalmoscopy, also called funduscopy, is a test that allows a health professional to see inside the fundus of the eye and other structures using an ophthalmoscope (or funduscope). It is done as part of an eye examination and may be done as part of a routine physical examination. It is crucial in determining the health of the retina, optic disc, and vitreous humor. The pupil is a hole through which the eye's interior can be viewed. For better viewing, the pupil can be opened wider (dilated; mydriasis) before ophthalmoscopy using medicated eye drops ( dilated fundus examination). However, undilated examination is more convenient (albeit not as comprehensive), and is the most common type in primary care. An alternative or complement to ophthalmoscopy is to perform a fundus photography, where the image can be analysed later by a professional. Types There are two major types of ophthalmoscopy: * direct ophthalmoscopy, which produces an upright (unreversed) image of approxima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dilated Fundus Examination
Dilated fundus examination (DFE) is a diagnostic procedure that uses mydriatic eye drops to dilate or enlarge the pupil in order to obtain a better view of the fundus of the eye. Once the pupil is dilated, examiners use ophthalmoscopy to view the eye's interior, which makes it easier to assess the retina, optic nerve head, blood vessels, and other important features. DFE has been found to be a more effective method for evaluating eye health when compared to non-dilated examination, and is the best method of evaluating structures behind the iris. It is frequently performed by ophthalmologists and optometrists as part of an eye examination. Examination The most common agents used to dilate the pupil are phenylephrine (2.5% in pediatrics or 10% in adults) and tropicamide (0.5% or 1%). While phenylephrine stimulates receptors that contract the dilator muscle of the pupil, tropicamide blocks stimulation of the pupillary sphincter muscle to allow for relaxation. As the insertio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinal Detachment
Retinal detachment is a condition where the retina pulls away from the tissue underneath it. It may start in a small area, but without quick treatment, it can spread across the entire retina, leading to serious vision loss and possibly blindness. Retinal detachment is a medical emergency that requires surgery. The retina is a thin layer at the back of the eye that processes visual information and sends it to the brain. When the retina detaches, common symptoms include seeing floaters, flashing lights, a dark shadow in vision, and sudden blurry vision. The most common type of retinal detachment is rhegmatogenous, which occurs when a tear or hole in the retina lets fluid from the center of the eye get behind it, causing the retina to pull away. Rhegmatogenous retinal detachment is most commonly caused by posterior vitreous detachment, a condition where the gel inside the eye breaks down and pulls on the retina. Risk factors include older age, nearsightedness ( myopia), eye injury, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinal Tuft
Retinal tuft (vitroretinal tuft) is a disorder or degeneration of the retina in the eye. Retinal tufts are classified as a peripheral retinal degenerations and can be categorized as either cystic or zonular tractional. Retinal tufts can be visualized or diagnosed using a dilated eye examination and indirect ophthalmoscope or a widefield retinal scan. A retinal tuft is a gliotic degeneration of the retina composed of focal adhesions in the extracellular matrix joining the retina and the posterior hyaloid of the eye. Retinal tufts are a common lesion of the retina and under 1% of these tufts are thought to lead to retinal detachment. The risk of a retinal detachment from a retinal tuft has been estimated to be about 0.28% and there is usually no treatment necessary for this condition. Cystic retinal tufts affect 5% of the population and are thought to be a congenital abnormality in the retina. Cystic tufts are more commonly found under the vitreous base in the peripheral of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lattice Degeneration
Lattice degeneration is a disease of the human eye wherein the peripheral retina becomes atrophic in a lattice pattern. Usually, this happens slowly over time and does not cause any symptoms, and medical intervention is neither needed nor recommended. Sometimes other retinal problems (such as tears, breaks, or holes) may be present along with lattice degeneration. However, these problems may also be distinct from or independent of lattice degeneration itself. The cause of lattice degeneration is unknown, but pathology reveals inadequate blood flow resulting in ischemia and fibrosis. The condition is common in those with myopia (nearsightedness). Prevalence and risk of retinal detachment Lattice degeneration is associated with retinal detachment, but the chance of developing retinal detachment if lattice degeneration exists is very low. Lattice degeneration occurs in approximately 6–8% of the general population and in approximately 30% of phakic retinal detachments. Similar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uveitis
Uveitis () is inflammation of the uvea, the pigmented layer of the eye between the inner retina and the outer fibrous layer composed of the sclera and cornea. The uvea consists of the middle layer of pigmented vascular structures of the eye and includes the iris, ciliary body, and choroid. Uveitis is described anatomically, by the part of the eye affected, as anterior, intermediate or posterior, or panuveitic if all parts are involved. Anterior uveitis ( iridocyclitis) is the most common, with the incidence of uveitis overall affecting approximately 1:4500, most commonly those between the ages of 20–60. Symptoms include eye pain, eye redness, floaters and blurred vision, and ophthalmic examination may show dilated ciliary blood vessels and the presence of cells in the anterior chamber. Uveitis may arise spontaneously, have a genetic component, or be associated with an autoimmune disease or infection. While the eye is a relatively protected environment, its immune mecha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cataract Surgery
Cataract surgery, also called lens replacement surgery, is the removal of the natural lens (anatomy), lens of the human eye, eye that has developed a cataract, an opaque or cloudy area. The eye's natural lens is usually replaced with an artificial intraocular lens (IOL) implant. Over time, metabolic changes of the crystalline lens fibres lead to the development of a cataract, causing impairment or loss of vision. Some infants are born with congenital cataracts, and environmental factors may lead to cataract formation. Early symptoms may include strong Glare (vision), glare from lights and small light sources at night and reduced visual acuity at low light levels. During cataract surgery, the cloudy natural lens is removed from the posterior chamber, either by emulsification in place or by cutting it out. An IOL is usually implanted in its place (PCIOL), or less frequently in front of the chamber, to restore useful focus. Cataract surgery is generally performed by an ophthalmolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myopia
Myopia, also known as near-sightedness and short-sightedness, is an eye condition where light from distant objects focuses in front of, instead of on, the retina. As a result, distant objects appear blurry, while close objects appear normal. Other symptoms may include headaches and eye strain. Severe myopia is associated with an increased risk of macular degeneration, retinal detachment, cataracts, and glaucoma. Myopia results from the length of the eyeball growing too long or less commonly the lens being too strong. It is a type of refractive error. Diagnosis is by the use of cycloplegics during eye examination. Tentative evidence indicates that the risk of myopia can be decreased by having young children spend more time outside. This decrease in risk may be related to natural light exposure. Myopia can be corrected with eyeglasses, contact lenses, or by refractive surgery. Eyeglasses are the simplest and safest method of correction. Contact lenses can provide a rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
