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Focal Choroidal Excavation
Focal choroidal excavation (FCE) is a concavity in the choroidal layer of the eye that can be detected by optical coherence tomography. The disease is usually unilateral and not associated with any accompanying systemic diseases. Pathophysiology Focal choroidal excavation (FCE) is a concavity in the choroidal layer of the eye without posterior staphyloma or scleral ectasia, that can be detected by optical coherence tomography. The concavity is commonly seen in the macular region. The disease is usually unilateral and not associated with any accompanying systemic diseases. Choroidal vascular disorders which cause visual symptoms, including central serous chorioretinopathy (CSCR), choroidal neovascularization (CNV), and polypoidal choroidal vasculopathy (PCV) may also present with focal choroidal excavation. Etiology The exact etiology of FCE is still (as of 2022) unknown. It was previously considered a congenital disease, but later it was suggested that FCEs can also occur with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophthalmology
Ophthalmology ( ) is a surgical subspecialty within medicine that deals with the diagnosis and treatment of eye disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a medical degree, a doctor specialising in ophthalmology must pursue additional postgraduate residency training specific to that field. This may include a one-year integrated internship that involves more general medical training in other fields such as internal medicine or general surgery. Following residency, additional specialty training (or fellowship) may be sought in a particular aspect of eye pathology. Ophthalmologists prescribe medications to treat eye diseases, implement laser therapy, and perform surgery when needed. Ophthalmologists provide both primary and specialty eye care - medical and surgical. Most ophthalmologists participate in academic research on eye diseases at some point in their training and many include research as part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Coherence Tomography
Optical coherence tomography (OCT) is an imaging technique that uses low-coherence light to capture micrometer-resolution, two- and three-dimensional images from within optical scattering media (e.g., biological tissue). It is used for medical imaging and industrial nondestructive testing (NDT). Optical coherence tomography is based on low-coherence interferometry, typically employing near-infrared light. The use of relatively long wavelength light allows it to penetrate into the scattering medium. Confocal microscopy, another optical technique, typically penetrates less deeply into the sample but with higher resolution. Depending on the properties of the light source ( superluminescent diodes, ultrashort pulsed lasers, and supercontinuum lasers have been employed), optical coherence tomography has achieved sub-micrometer resolution (with very wide-spectrum sources emitting over a ~100 nm wavelength range). Optical coherence tomography is one of a class of optical tom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choroid
The choroid, also known as the choroidea or choroid coat, is a part of the uvea, the vascular layer of the eye, and contains connective tissues, and lies between the retina and the sclera. The human choroid is thickest at the far extreme rear of the eye (at 0.2 mm), while in the outlying areas it narrows to 0.1 mm. The choroid provides oxygen and nourishment to the outer layers of the retina. Along with the ciliary body and iris, the choroid forms the uveal tract. The structure of the choroid is generally divided into four layers (classified in order of furthest away from the retina to closest): *Haller's layer - outermost layer of the choroid consisting of larger diameter blood vessels; *Sattler's layer - layer of medium diameter blood vessels; * Choriocapillaris - layer of capillaries; and *Bruch's membrane (synonyms: Lamina basalis, Complexus basalis, Lamina vitra) - innermost layer of the choroid. Blood supply There are two circulations of the eye: the retin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staphyloma
A staphyloma is an abnormal protrusion of the uveal tissue through a weak point in the eyeball. The protrusion is generally black in colour, due to the inner layers of the eye. It occurs due to weakening of outer layer of eye (cornea or sclera) by an inflammatory or degenerative condition. It may be of five types, depending on the location on the eyeball (''bulbus oculi''). Anterior (corneal) staphyloma In the anterior segment of the eye, involving the cornea and the nearby sclera. It is an ectasia of pseudocornea ( the scar formed from organised exudates and fibrous tissue covered with epithelium) which results after sloughing of cornea with iris plastered behind, it is known as anterior staphyloma. Intercalary staphyloma It is the name given to the localised bulge in limbal area, lined by the root of the iris. It results due to ectasia of weak scar tissue formed at the limbus, following healing of a perforating injury or a peripheral corneal ulcer. There may be associated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macula
The macula (/ˈmakjʊlə/) or macula lutea is an oval-shaped pigmented area in the center of the retina of the human eye and in other animals. 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 a size of is much larger than the clinical macula which, at a size of , 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 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". Structure The macula is an oval-shaped pigmented area in the center of the retina of the human eye and other animal eyes. Its center is shifted slightly away from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Serous Chorioretinopathy
Central serous chorioretinopathy (CSC or CSCR), also known as central serous retinopathy (CSR), is an eye disease that causes visual impairment, often temporary, usually in one eye. When the disorder is active it is characterized by leakage of fluid under the retina that has a propensity to accumulate under the central macula. This results in blurred or distorted vision (metamorphopsia). A blurred or gray spot in the central visual field is common when the retina is detached. Reduced visual acuity may persist after the fluid has disappeared. The disease is considered of unknown cause. It mostly affects white males in the age group 20 to 50 (male:female ratio 6:1) and occasionally other groups. The condition is believed to be exacerbated by stress or corticosteroid use. Pathophysiology Recently, central serous chorioretinopathy has been understood to be part of the pachychoroid spectrum. In pachychoroid spectrum disorders, of which CSR represents stage II, the choroid, the high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choroidal Neovascularization
Choroidal neovascularization (CNV) is the creation of new blood vessels in the choroid layer of the eye. Choroidal neovascularization is a common cause of neovascular degenerative maculopathy (i.e. 'wet' macular degeneration) commonly exacerbated by extreme myopia, malignant myopic degeneration, or age-related developments. Causes CNV can occur rapidly in individuals with defects in Bruch's membrane, the innermost layer of the choroid. It is also associated with excessive amounts of vascular endothelial growth factor (VEGF). As well as in wet macular degeneration, CNV can also occur frequently with the rare genetic disease pseudoxanthoma elasticum and rarely with the more common optic disc drusen. CNV has also been associated with extreme myopia or malignant myopic degeneration, where in choroidal neovascularization occurs primarily in the presence of cracks within the retinal (specifically) macular tissue known as lacquer cracks. Symptoms CNV can create a sudden deterioration o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polypoidal Choroidal Vasculopathy
Polypoidal choroidal vasculopathy (PCV) is an eye disease primarily affecting the choroid. It may cause sudden blurring of vision or a scotoma in the central field of vision. Since Indocyanine green angiography gives better imaging of choroidal structures, it is more preferred in diagnosing PCV. Treatment options of PCV include careful observation, photodynamic therapy, Gas dynamic laser, thermal laser, intravitreal injection of Anti–vascular endothelial growth factor therapy, anti-VEGF therapy, or combination therapy. Pathophysiology PCV is an ocular disease characterised by abnormally shaped vessels in the choroid. It is described as an exudative maculopathy, characterised by multiple recurrent serosanguineous Retinal pigment epithelium, retinal pigment epithelial detachments. Elevated reddish to orange lesions on fundus examination, dilated inner choroidal vessels, and polypoidal vascular structures beneath the retinal detachment are other features of PCV. Etiology PCV is bel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choroidal Atrophy
The choroid, also known as the choroidea or choroid coat, is a part of the uvea, the vascular layer of the eye, and contains connective tissues, and lies between the retina and the sclera. The human choroid is thickest at the far extreme rear of the eye (at 0.2 mm), while in the outlying areas it narrows to 0.1 mm. The choroid provides oxygen and nourishment to the outer layers of the retina. Along with the ciliary body and iris, the choroid forms the uveal tract. The structure of the choroid is generally divided into four layers (classified in order of furthest away from the retina to closest): *Haller's layer - outermost layer of the choroid consisting of larger diameter blood vessels; *Sattler's layer - layer of medium diameter blood vessels; *Choriocapillaris - layer of capillaries; and *Bruch's membrane (synonyms: Lamina basalis, Complexus basalis, Lamina vitra) - innermost layer of the choroid. Blood supply There are two circulations of the eye: the retinal ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choroiditis
Chorioretinitis is an inflammation of the choroid (thin pigmented vascular coat of the eye) and retina of the eye. It is a form of posterior uveitis. If only the choroid is inflamed, not the retina, the condition is termed choroiditis. The ophthalmologist's goal in treating these potentially blinding conditions is to eliminate the inflammation and minimize the potential risk of therapy to the patient. Symptoms Symptoms may include the presence of floating black spots, blurred vision, pain or redness in the eye, sensitivity to light, or excessive tearing. Causes Chorioretinitis is often caused by toxoplasmosis and cytomegalovirus infections (mostly seen in immunodeficient subjects such as people with HIV/AIDS or on immunosuppressant drugs). Congenital toxoplasmosis via transplacental transmission can also lead to sequelae such as chorioretinitis along with hydrocephalus and cerebral calcifications. Other possible causes of chorioretinitis are syphilis, sarcoidosis, tuberculosis, Be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Acuity
Visual acuity (VA) commonly refers to the clarity of vision, but technically rates an examinee's ability to recognize small details with precision. Visual acuity is dependent on optical and neural factors, i.e. (1) the sharpness of the retinal image within the eye, (2) the health and functioning of the retina, and (3) the sensitivity of the interpretative faculty of the brain. The most commonly referred visual acuity is the far acuity (e.g. 6/6 or 20/20 acuity), which describes the examinee's ability to recognize small details at a far distance, and is relevant to people with myopia; however, for people with hyperopia, the near acuity is used instead to describe the examinee's ability to recognize small details at a near distance. A common cause of low visual acuity is refractive error (ametropia), errors in how the light is refracted in the eyeball, and errors in how the retinal image is interpreted by the brain. The latter is the primary cause for low vision in people with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
