Introduction to Ocular Surface Squamous Neoplasia
Ocular Surface Squamous Neoplasia (OSSN) refers to a group of malignant and pre-malignant lesions that develop from the squamous epithelium of the ocular surface, primarily affecting the conjunctiva and cornea. OSSN encompasses conditions ranging...
What is ocular myasthenia gravis?
Ocular Myasthenia Gravis (OMG) is a subset of myasthenia gravis, an autoimmune disorder that causes weakness and rapid fatigue of the voluntary muscles. OMG specifically affects the muscles that control eye movements and eyelids, resulting...
Ocular migraine, also known as retinal migraine or visual migraine, is a condition characterized by brief visual disturbances that usually affect only one eye. These disturbances may include flashing lights, blind spots, or even temporary vision loss. Unlike classic...
Ocular hypertension is a condition characterized by high intraocular pressure (IOP) in the eye, which increases the risk of developing glaucoma, a serious eye disease that can cause vision loss and blindness. Unlike glaucoma, ocular hypertension does not initially...
Ocular Histoplasmosis Syndrome (OHS) is a severe eye infection caused by the fungus Histoplasma capsulatum. This fungus is common in soil, particularly in areas where birds and bats live. Inhalation of fungal spores can cause histoplasmosis, a systemic infection...
Ocular cicatricial pemphigoid (OCP) is a chronic autoimmune inflammatory disease that primarily affects the conjunctiva and other mucous membranes of the eyes. It is a subtype of mucous membrane pemphigoid (MMP) that causes progressive scarring of the conjunctiva, which...
Ocular chemical burns are a severe and potentially blinding condition caused by exposing the eyes to toxic chemicals. Burns can occur as a result of accidental splashes, industrial accidents, or exposure to household cleaning agents, among other causes. The...
Nystagmus is an ocular condition in which the eyes oscillate involuntarily and rhythmically. These movements can be horizontal, vertical, or rotational, and they frequently result in blurred vision and difficulty maintaining steady focus. Nystagmus can be congenital, meaning it...
What is nutritional optic neuropathy?
Nutritional optic neuropathy (NON) is an ocular condition that causes damage to the optic nerve due to nutritional deficiencies. The optic nerve transmits visual information from the retina to the brain, and any impairment in...
Nuclear sclerosis is a common age-related condition that affects the eye's lens, causing it to harden and yellow over time. This condition is a type of cataract that is frequently associated with the natural aging process. As the lens...
Normal-tension glaucoma (NTG) is a type of open-angle glaucoma that causes optic nerve damage and visual field loss despite having a normal intraocular pressure (IOP) (10-21 mmHg). Unlike other types of glaucoma, where elevated IOP is a significant risk...
Introduction
Non-infectious endophthalmitis is an inflammatory condition that affects the inside of the eye, specifically the vitreous and aqueous humors. Non-infectious endophthalmitis, as opposed to infectious endophthalmitis, is caused by an autoimmune reaction, trauma, or surgery, rather than bacterial, fungal,...
Non-arteritic anterior ischemic optic neuropathy (NAION) is a condition in which vision loss occurs suddenly due to insufficient blood flow to the optic nerve head. This condition primarily affects adults over the age of 50 and is one of...
Neuroretinitis is an ocular condition that causes inflammation of the optic nerve (optic neuritis) and the retina. It usually begins with sudden, painless vision loss in one eye, which is frequently accompanied by a central scotoma (a dark spot...
Neuromyelitis Optica (NMO), also known as Devic's disease, is a rare autoimmune disorder affecting primarily the optic nerves and spinal cord. It is defined by severe attacks of optic neuritis, which causes inflammation of the optic nerve, resulting in...
Neurofibromatosis (NF) is a genetic disorder characterized by the growth of tumors along nerves in the skin, brain, and other parts of the body. These tumors, known as neurofibromas, are typically benign but can cause serious health problems depending...
What is neurofibroma of the orbit?
Neurofibroma of the orbit is a benign tumor that develops from nerve sheath cells in the orbital cavity, which is the bony socket that houses the eye. This condition is commonly associated with Neurofibromatosis...
Neovascularization of the vitreous is a serious ocular condition characterized by the formation of new, abnormal blood vessels in the vitreous humor, a gel-like substance that fills the eye. These new blood vessels are often fragile and prone to...
Neovascular Glaucoma (NVG) is a severe type of secondary glaucoma characterized by the formation of new, abnormal blood vessels on the iris and drainage angle of the eyeball. These new blood vessels may obstruct the eye's drainage system, resulting...
What is necrotizing scleritis?
Necrotizing scleritis is a serious and potentially blinding ocular condition characterized by inflammation and necrosis of the sclera, the white outer layer of the eyeball. This condition is frequently associated with systemic autoimmune diseases, including rheumatoid...
Introduction
Nasolacrimal duct obstruction (NLDO) is a condition characterized by a blockage in the nasolacrimal duct, which drains tears from the eye into the nasal cavity. This blockage prevents the normal flow of tears, resulting in excessive tearing, recurring eye...
What is myopic maculopathy?
Myopic maculopathy, also known as myopic macular degeneration, is a serious ocular condition associated with high myopia in which excessive elongation of the eyeball causes degenerative changes in the retina, specifically the macula. The macula is...
Introduction to Myopia?
Myopia, also known as nearsightedness, is a common refractive error in which distant objects appear blurry while close objects are visible clearly. This condition develops when the eye is elongated or the cornea has excessive curvature, causing...
What is multifocal choroiditis and panuveitis?
Multifocal choroiditis and panuveitis (MCP) is a rare and complicated inflammatory eye disease affecting the choroid, retina, and vitreous. It is distinguished by multiple inflammatory lesions in the choroid and retina, which frequently progress...
Definition of Mucoepidermoid Carcinoma of the Lacrimal Gland
Mucoepidermoid carcinoma of the lacrimal gland is a rare but aggressive malignant tumor that develops from the epithelial cells of the lacrimal gland. The lacrimal gland, which produces tears, is located in...
What is a microstrabismus?
Microstrabismus, also known as microtropia, is a subtle form of strabismus (eye misalignment) in which the deviation is very small, usually less than 5 degrees. Unlike more visible forms of strabismus, microstrabismus is frequently difficult to...
Introduction
Microphthalmia is a rare congenital disorder characterized by underdevelopment of one or both eyes. The term "microphthalmia" comes from Greek, where "micro" means small and "ophthalmos" means eye. Microphthalmia is characterized by abnormally small eye(s) and other structural anomalies,...
What is Melanoma of the Eyelid?
Melanoma of the eyelid is a rare but serious type of skin cancer that develops from melanocytes, the skin's pigment-producing cells. This condition is a subset of periocular melanomas, which include melanomas in the...
Understanding Melanocytoma of the Optic Disc
Melanocytoma of the optic disc is a rare, benign tumor that develops from melanocytes, the cells that produce pigment in the body. These tumors are typically found on or near the optic disc, which...
What is the Meibomian Gland Dysfunction?
Meibomian gland dysfunction (MGD) is a common and often chronic condition that affects the meibomian glands in the eyelids, which secrete the lipid (oily) layer of the tear film. This lipid layer is essential...
