Introduction
Malignant melanoma of the eyelid is a rare but aggressive type of skin cancer that develops from melanocytes, the pigment-producing cells in the skin. This condition falls under the category of periocular melanomas, which also includes melanomas of the...
What is malignant glaucoma?
Malignant glaucoma, also known as aqueous misdirection or ciliary block glaucoma, is a rare but serious type of glaucoma characterized by the misdirection of aqueous humor, the fluid inside the eye, into or around the vitreous...
Introduction to Macular Pucker
A macular pucker, also known as epiretinal membrane (ERM), is an ocular condition in which a thin layer of fibrous tissue forms on the macula's surface. The macula is the central part of the retina that...
What is a macular hole?
A macular hole is a small break or tear in the macula, the central part of the retina that allows for clear, detailed vision. The macula enables us to perform tasks requiring fine visual detail,...
Understanding Lenticonus and Lentiglobus
Lenticonus and lentiglobus are rare congenital lens deformities that severely impair vision. Lenticonus is characterized by a conical protrusion of the lens surface, which usually affects the anterior or posterior lens. This deformation causes irregular astigmatism...
What causes Leber's Hereditary Optic Neuropathy?
LHON is a rare inherited mitochondrial disorder that causes sudden and severe vision loss. It primarily affects young adults, usually between the ages of 15 and 35, but it can happen at any age....
What is Leber's Congenital Amaurosis?
Leber Congenital Amaurosis (LCA) is a rare inherited retinal dystrophy that causes severe vision loss or blindness at birth or during early childhood. It is named after Theodor Leber, a German ophthalmologist who first described...
What is lattice dystrophy?
Lattice dystrophy is a hereditary corneal condition characterized by the accumulation of abnormal protein deposits called amyloid in the corneal stroma. These deposits form a lattice-like pattern, hence their name. Lattice dystrophy typically appears in the...
Latent Nystagmus Introduction
Latent nystagmus is a type of involuntary eye movement that usually appears when one eye is covered or binocular vision is impaired. This condition is frequently congenital and is associated with infantile strabismus and other types of...
Lagophthalmos Overview
Lagophthalmos is an ocular condition defined by the inability to fully close the eyelids, resulting in incomplete or partial eye closure. This condition can progress to exposure keratopathy, in which the cornea becomes dry, irritated, and vulnerable to...
What is a Lacrimal Gland Tumor?
Lacrimal gland tumors are a wide range of neoplasms that develop from the lacrimal gland, which is located in the upper outer region of the orbit. These tumors can be benign or malignant, with...
What is lacrimal gland prolapse?
Lacrimal gland prolapse is an ocular condition in which the lacrimal gland moves downward from its normal location in the lacrimal fossa in the upper outer quadrant of the orbit. This gland produces tears, which...
What is Lacrimal Gland Dislocation?
Lacrimal gland dislocation is a condition in which the lacrimal gland, which produces tears, moves out of its normal anatomical position. This gland, located in the upper outer quadrant of the orbit, just above the...
What is a Lacrimal Fistula?
A lacrimal fistula is an abnormal connection or passageway formed between the lacrimal sac (a component of the tear drainage system) and the skin or other anatomical structures. This condition can cause chronic tearing (epiphora),...
What is Lacrimal Duct Obstruction?
Lacrimal duct obstruction, also known as nasolacrimal duct obstruction (NLDO), is a condition that occurs when the tear ducts become clogged, preventing tears from draining properly from the eye into the nasal cavity. This causes...
What is keratoconus?
Keratoconus is a progressive eye condition in which the normally round, dome-shaped cornea thins and bulges into a cone-like shape. This abnormal shape deflects light as it enters the eye, resulting in distorted vision. The exact cause...
What is keratitis?
Keratitis is an inflammation of the cornea, which is the clear front part of the eye that protects the iris, pupil, and anterior chamber. Infections (bacterial, viral, fungal, or parasitic), physical or chemical injury, and underlying systemic...
What is Juvenile Open Angle Glaucoma?
Juvenile open-angle glaucoma (JOAG) is a rare but serious form of glaucoma that affects children, adolescents, and young adults aged 10 to 35. It is distinguished by an increase in intraocular pressure (IOP) as...
What is ischemic optic neuropathy?
Ischemic optic neuropathy (ION) is a condition that causes sudden loss of vision due to insufficient blood flow to the optic nerve. The optic nerve is responsible for transmitting visual information from the retina to...
What is iritis?
Iritis, also known as anterior uveitis, is an inflammation of the iris, the colored area of the eye that surrounds the pupil. It is a subset of uveitis, which is defined as inflammation of the uvea, the...
What is Iris Nevus?
An iris nevus is a harmless pigmented lesion on the iris, the colored portion of the eye. These lesions are usually flat, but they may occasionally be slightly elevated. Melanocytes, the cells responsible for pigment production,...
What is Iris Dialysis?
Iris dialysis is a condition in which the iris detaches or separates from its ciliary attachments. This ocular condition is frequently the result of eye trauma, such as blunt force injuries, surgical complications, or penetrating injuries....
What is intraocular lymphoma?
Intraocular lymphoma is a rare and aggressive type of cancer that affects the eye. It is a subtype of primary central nervous system lymphoma (PCNSL), a type of non-Hodgkin lymphoma. Intraocular lymphoma primarily affects the retina,...
What is internuclear ophthalmoplegia?
Internuclear ophthalmoplegia (INO) is a neurological condition characterized by decreased horizontal eye movement. A lesion in the medial longitudinal fasciculus (MLF), a bundle of nerve fibers that connects the cranial nerve nuclei involved in horizontal gaze,...
What is intermediate uveitis?
Intermediate uveitis is a type of uveitis, which is an inflammatory condition affecting the uvea, the eye's middle layer. Intermediate uveitis primarily affects the vitreous and peripheral retina. The condition can cause significant visual disturbances and,...
What is infectious uveitis?
Infectious uveitis is a type of uveitis, which is an inflammatory condition affecting the uvea, the middle layer of the eye that contains the iris, ciliary body, and choroid. Infectious agents such as bacteria, viruses, fungi,...
What is Infectious Endophthalmitis?
Infectious endophthalmitis is a severe and potentially blinding inflammation of the eye's interior that is typically caused by a bacterial or fungal infection. This condition usually affects the vitreous and aqueous humors and can result in...
What is hypotropia?
Hypotropia is a type of strabismus in which one eye deviates downward relative to the other, causing misalignment. This condition can be congenital or acquired, and it may be associated with other ocular or systemic issues. Hypotropia...
What is hypophoria?
Hypophoria is an ocular condition defined by a latent tendency for one eye to drift downward when the eyes are not actively focusing on a single target. Unlike manifest strabismus, which is always visible, hypophoria is latent...
What is hyphema?
Hyphema is an ocular condition characterized by the presence of blood in the anterior chamber of the eye, which is located between the cornea and the iris. This condition is typically caused by eye trauma, such as...
