What is Branch Retinal Vein Occlusion?
Branch retinal vein occlusion (BRVO) is a common vascular disorder affecting the retina, the light-sensitive tissue located in the back of the eye. This condition develops when one of the smaller branches of the...
What is branch retinal artery occlusion?
Branch retinal artery occlusion (BRAO) is a serious ophthalmic condition characterized by the blockage of one of the smaller arteries that branch off from the central retinal artery. This blockage causes a sudden and...
What is Blue Sclera?
Blue sclera is a condition that causes the sclera, the white part of the eye, to appear unusually bluish. This distinct appearance results from scleral tissue thinning, which makes the underlying blue uveal tissue more visible....
What is a blowout fracture?
A blowout fracture is a traumatic injury to the orbit, the bony socket that surrounds the eye. This condition is typically caused by blunt force trauma, such as a punch or ball impact, and involves...
Definition of Mucoepidermoid Carcinoma of the Lacrimal Gland
Mucoepidermoid carcinoma of the lacrimal gland is a rare and aggressive malignant tumor that develops from the epithelial cells of the lacrimal gland. The lacrimal gland, which is located in the upper...
What is Migraine With Aura (Ophthalmic Migraine)?
Migraine with aura, also known as ophthalmic migraine, is a neurological disorder characterized by recurrent headaches and visual or sensory disturbances known as auras. These auras usually occur before the headache phase and...
What is a microstrabismus?
Microstrabismus, also known as microtropia, is a subtle type of strabismus characterized by a very slight misalignment of the eyes, usually less than 5 degrees. This small-angle deviation frequently goes unnoticed without specialized examination. Despite its...
What is microphthalmia?
Microphthalmia is a congenital ocular condition in which one or both eyes are abnormally small and malformed. This condition can range in severity from slightly smaller-than-normal eyes to severely underdeveloped eyes, and it is sometimes associated with...
What is Melanoma of the Eyelid?
Melanoma of the eyelid is a rare but potentially fatal cancer that arises from melanocytes, the pigment-producing cells in the skin. This cancer accounts for only a small percentage of all skin cancers, but...
What is Melanocytoma of the Optic Disc?
Melanocytoma of the optic disc is a rare, benign pigmented tumor that develops near the optic nerve head. These tumors are typically dark brown to black in color due to their high melanin...
What is blepharospasm?
Blepharospasm is a neurological condition characterized by involuntary, repetitive spasms or contractions of the eyelid muscles, which cause frequent blinking and eye closure. This disorder, which belongs to the larger category of focal dystonias, primarily affects the...
What is blepharochalasis?
Blepharochalasis is a rare chronic eyelid disorder that causes recurrent episodes of painless swelling of the eyelids. These episodes cause the skin on the eyelids to thin, stretch, and wrinkle, giving the eyes an aged or fatigued...
What is blepharitis?
Blepharitis is a common, chronic inflammatory condition of the eyelids that causes redness, swelling, and irritation. It frequently appears at the base of the eyelashes and can affect both the anterior (front) and posterior (back) portions of...
What is Birdshot Chorioretinopathy?
Birdshot chorioretinopathy, also called birdshot retinochoroidopathy, is a rare, chronic inflammatory condition that affects the retina and choroid of the eye. This condition is named after the characteristic appearance of cream-colored spots on the retina that...
What is Bilateral Diffuse Uveal Melanocyte Proliferation (BDUMP)?
Bilateral diffuse uveal melanocytic proliferation (BDUMP) is a rare paraneoplastic syndrome defined by the bilateral proliferation of benign melanocytic cells in the uveal tract of the eyes, which includes the iris, ciliary...
What is the Meibomian Gland Dysfunction?
Meibomian gland dysfunction (MGD) is a common ocular condition characterized by the obstruction or irregular secretion of the meibomian glands, which are required to maintain a healthy tear film. These glands in the eyelids...
What is Marfan syndrome?
Marfan syndrome is a genetic disorder that affects the connective tissue that structures and supports the body's organs and tissues. Mutations in the FBN1 gene cause this syndrome, which is characterized by defective fibrillin-1, a protein...
What is Marfan syndrome?
Marfan syndrome is a genetic disorder that affects the connective tissue that structures and supports the body's organs and tissues. One of the most common ocular manifestations of Marfan syndrome is lens dislocation, also known as...
What is Marcus Gunn's Jaw-Winking Syndrome?
Marcus Gunn Jaw-Winking Syndrome (MGJWS) is a rare congenital condition characterized by an abnormal synkinetic movement of the eyelid, in which the upper eyelid elevates or "winks" in response to jaw movements such as...
What is Map-Dot Fingerprint Dystrophy?
Map-Dot-Fingerprint Dystrophy, also known as epithelial basement membrane dystrophy (EBMD) or Cogan's microcystic epithelial dystrophy, is a common and usually benign corneal condition. The corneal epithelium is irregular, resulting in a pattern of maps, dots,...
What is Bietti Crystalline Dystrophy?
Bietti's crystalline dystrophy (BCD) is a rare inherited retinal disorder that causes progressive vision loss due to the accumulation of crystalline deposits in the retina and corneal limbus. G. B. Bietti, an Italian ophthalmologist, first...
What is basal cell carcinoma of the eyelid?
Basal cell carcinoma (BCC) of the eyelid is a type of skin cancer that begins in the skin's outermost layer, where basal cells reside. It is the most common type of eyelid...
What is Astigmatism?
Astigmatism is a common refractive error that results in blurred or distorted vision. It happens when the cornea, the clear front surface of the eye, or the lens within the eye has an irregular shape. The cornea...
What is Arteritic Anterior Ischemic Optic Neuropathy (AAION)?
Arteritic anterior ischemic optic neuropathy (AAION) is a serious and potentially vision-threatening condition that causes sudden loss of vision due to insufficient blood flow to the optic nerve head. This ischemic event...
What is Asteroid Hyalosis?
Asteroid hyalosis is an ocular condition characterized by the presence of small, white, spherical opacities known as "asteroid bodies" within the vitreous humor of the eye. These opacities are primarily calcium and phosphate-based, and they frequently...
What is malignant melanoma of the eyelid?
Malignant melanoma of the eyelid is a rare but aggressive type of skin cancer that develops from melanocytes, pigment-producing cells found in the skin of the eyelid. This condition has the potential to...
What is malignant glaucoma?
Malignant glaucoma, also referred to as aqueous misdirection or ciliary block glaucoma, is a rare but severe type of glaucoma. It is most common after eye surgery, but it can also occur on its own. An...
What is Macular Pucker?
Macular pucker, also known as epiretinal membrane (ERM) or cellophane maculopathy, is an ocular condition characterized by the formation of a thin layer of fibrous tissue on the retinal macula. The macula is the area of...
What is a macular hole?
A macular hole is a small break or tear in the macula, the central part of the retina that provides the sharp, detailed vision required for tasks like reading and face recognition. The condition primarily...
What is Lowe syndrome?
Lowe syndrome, also called oculocerebrorenal syndrome, is a rare genetic condition that affects the eyes, brain, and kidneys. Mutations in the OCRL gene on the X chromosome cause phosphatidylinositol 4,5-bisphosphate 5-phosphatase deficiency. This enzyme deficiency causes...
