What is orbital lymphoma?
Orbital lymphoma is a rare type of cancer that develops in lymphocytes, which are white blood cells found in the tissues of the orbit, the bony cavity that houses the eye. This cancer can affect the...
Orbital hemorrhage is the accumulation of blood within the orbit, the bony cavity that houses the eye. This condition can be caused by trauma, such as blunt or penetrating injuries, surgical complications, vascular abnormalities, or spontaneous bleeding disorders. The...
Orbital fractures are breaks or cracks in the bones surrounding the eye, known as the orbit. These fractures are most commonly caused by blunt trauma to the face, such as sports injuries, falls, car accidents, or physical assaults. The...
Orbital cellulitis is a serious bacterial infection that affects the tissues around the eye, such as the eyelids, brows, and cheek. It is usually caused by the spread of infection from the sinuses or direct trauma to the area...
Optic neuritis is an inflammatory condition of the optic nerve, which transmits visual information from the eye to the brain. This condition can result in sudden vision loss, pain during eye movement, and visual field defects. Optic neuritis is...
Optic nerve sheath meningioma (ONSM) is a rare, usually benign tumor that develops from the meninges, the protective membranes that surround the optic nerve. This condition primarily affects middle-aged adults and is more prevalent in women than in men....
Optic nerve pit is a rare congenital anomaly marked by a small, crater-like depression in the optic disc, where the optic nerve enters the eye. This condition is typically present from birth and can affect one or both eyes....
Optic nerve meningioma is a benign tumor that develops from the meninges, the protective membranes that surround the brain and spinal cord. It specifically targets the optic nerve, which is responsible for transmitting visual information from the eyes to...
Optic nerve hypoplasia (ONH) is a congenital condition marked by underdevelopment of the optic nerve, which transmits visual information from the retina to the brain. This condition can affect one or both eyes and is usually diagnosed during infancy...
Optic nerve head avulsion (ONHA) is a rare but serious ocular condition in which the optic nerve head, the point where the optic nerve connects to the retina, is forcibly detached as a result of trauma. This injury is...
Optic nerve glioma, also called optic pathway glioma, is a rare type of brain tumor that affects the optic nerve, which transmits visual information from the eyes to the brain. This condition primarily affects children, particularly those under the...
Optic disc pallor is a pale appearance of the optic disc, the visible portion of the optic nerve located at the back of the eye. This condition indicates optic nerve damage or atrophy, which can be caused by a...
Optic disc drusen (ODD) is an ocular condition marked by the formation of calcified deposits within the optic nerve head. These deposits, primarily composed of proteins and calcium salts, can cause structural changes and compression of the optic nerve...
Optic disc coloboma is a congenital eye condition characterized by an abnormality in the optic nerve head, which causes a portion of the optic disc to appear missing or excavated. This defect occurs when the embryonic fissure is not...
Optic atrophy is the damage and degeneration of the optic nerve, which transmits visual information from the retina to the brain. This condition can cause a gradual decline in vision and, in severe cases, complete blindness. Ischemia (lack of...
Ophthalmia Neonatorum (ON) is a type of conjunctivitis that typically affects newborns within the first 28 days of life. Bacteria, viruses, and chemicals can all cause neonatal conjunctivitis. The most common bacterial pathogens responsible for ON are Neisseria gonorrhoeae...
The nematode Onchocerca volvulus causes onchocerciasis, also known as river blindness. Infected blackflies of the genus Simulium bite humans and transmit the disease. Onchocerciasis primarily affects people in Sub-Saharan Africa, with some cases reported in Latin America and Yemen....
Toxoplasma gondii causes ocular toxoplasmosis, an eye infection. It is the most common cause of posterior uveitis, which is an inflammation of the back of the eye that can cause significant vision loss if not treated properly. The parasite...
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,...
