Tuberculosis (TB) of the eye, also known as ocular tuberculosis, is a rare form of Mycobacterium tuberculosis infection that affects primarily the lungs. Ocular tuberculosis can affect multiple parts of the eye, including the conjunctiva, cornea, sclera, uvea, retina,...
What is trichiasis?
Trichiasis is an eye condition characterized by abnormal inward growth of the eyelashes, causing them to rub against the cornea and conjunctiva. If not treated, this condition can cause significant discomfort, pain, and damage to the eye's...
Traumatic vitreous hemorrhage occurs when blood leaks into the vitreous humor of the eye, which is the clear gel that fills the space between the lens and the retina, as a result of ocular trauma. This type of hemorrhage...
What is traumatic uveitis?
Traumatic uveitis is an inflammation of the uveal tract of the eye, which includes the iris, ciliary body, and choroid, caused by ocular trauma. This condition can result from blunt force, penetrating injuries, or chemical exposure,...
Traumatic optic neuropathy (TON) is a serious vision-threatening condition caused by optic nerve trauma. This injury can occur as a result of blunt force trauma, penetrating injuries, or indirect forces like rapid acceleration or deceleration. The optic nerve, which...
Traumatic iritis is an inflammatory condition of the iris, or colored part of the eye, caused by blunt or penetrating trauma. Traumatic iritis, as opposed to infectious or autoimmune iritis, is caused directly by physical injury. If not treated...
What is traumatic glaucoma?
Traumatic glaucoma is a type of secondary glaucoma that develops after an eye injury. This condition can result from blunt trauma, penetrating injuries, or chemical burns that damage the ocular structures, causing elevated intraocular pressure (IOP)....
Traumatic endophthalmitis is a serious and vision-threatening ocular condition caused by the introduction of infectious agents into the eye after a penetrating injury. This condition is characterized by inflammation of the intraocular tissues, particularly the vitreous and aqueous humors....
Traumatic cataract is an ocular condition in which the crystalline lens of the eye becomes opaque as a result of an injury. Unlike age-related cataracts, which form gradually over time, traumatic cataracts can form quickly after a direct impact,...
The bacterium Chlamydia trachomatis causes trachoma, a highly contagious ocular condition. It is the most common infectious cause of blindness worldwide, primarily affecting impoverished communities in developing countries. The disease spreads directly through infected individuals' eye discharge, as well...
What is syphilitic uveitis?
Syphilitic uveitis is a side effect of syphilis, a sexually transmitted infection caused by the bacterium Treponema pallidum. This ocular condition can develop at any stage of syphilis, but it is most commonly associated with the...
Synchysis scintillans is a rare degenerative eye condition characterized by the presence of cholesterol crystals suspended in the vitreous humor, a clear gel that fills the space between the lens and the retina. When viewed through an ophthalmoscope, these...
What is sympathetic ophthalmia?
Sympathetic ophthalmia (SO) is a rare granulomatous uveitis that develops after a penetrating injury or surgery to one eye, resulting in an autoimmune response that affects both eyes. This condition is defined by inflammation that begins...
Definition of Lens Subluxation
Subluxation of the lens, also known as lens dislocation, is an ocular condition in which the natural lens of the eye is displaced from its original position. This can happen due to weakened or broken zonules,...
Subconjunctival hemorrhage is a common ocular condition defined by the sudden appearance of a bright red or dark patch on the white part of the eye (sclera). This condition occurs when small blood vessels beneath the conjunctiva, the transparent...
Strabismus, also known as "crossed eyes," is a condition in which the eyes do not properly align. One eye can turn inward, outward, upward, or downward, while the other focuses on an object. This misalignment can occur continuously or...
What is Strabismic Amblyopia?
Strabismic amblyopia, also known as "lazy eye," is a vision development disorder in which an eye fails to achieve normal visual acuity, usually due to strabismus, or misalignment of the eyes. When one eye is misaligned,...
Squamous cell carcinoma (SCC) of the eyelid is a malignant tumor that develops from squamous cells, which are flat cells that line the skin's surface. It is the second most common type of eyelid cancer, trailing only basal cell...
Solar retinopathy is an ocular condition caused by direct exposure to intense sunlight or other sources of ultraviolet (UV) radiation, such as during a solar eclipse or prolonged sun exposure. This condition occurs when UV rays damage the retina,...
What is sickle cell retinopathy?
Sickle cell retinopathy is a serious ocular condition that affects people who have sickle cell disease (SCD), a genetic blood disorder defined by the production of abnormal hemoglobin known as hemoglobin S. This condition causes...
Serpiginous choroiditis, also known as geographic choroidopathy, is a rare, chronic, and progressive inflammatory disease of the choroid and retinal pigment epithelium (RPE) of the eye. Serpentine or snake-like lesions spread centrifugally from the optic disc and involve the...
What is secondary glaucoma?
Secondary glaucoma is a type of glaucoma that develops as a result of another eye condition or injury. Secondary glaucoma, as opposed to primary glaucoma, is caused by eye trauma, inflammation, tumors, advanced cataracts, diabetes, or...
What is secondary cataract?
Secondary cataract, also known as posterior capsular opacification (PCO), is a common complication that can develop following cataract surgery. While cataract surgery removes the cloudy lens and replaces it with an artificial intraocular lens (IOL), the...
Definition of Secondary Acquired Lacrimal Duct Obstruction
Secondary acquired lacrimal duct obstruction (SALDO) is a condition in which the tear drainage system of the eye becomes clogged due to an external factor or underlying disease, causing excessive tearing (epiphora) and...
Scleromalacia perforans is a severe, progressive form of scleritis that causes thinning and degeneration of the sclera, the white outer layer of the eye, with no significant inflammation. This condition is frequently associated with autoimmune diseases, specifically rheumatoid arthritis....
What is scleritis?
Scleritis is a severe inflammatory disease of the sclera, the white outer layer of the eye. This condition is characterized by severe pain, redness, and tenderness in the eye, and if not treated properly, it can cause...
Scleral staphyloma is a serious ocular condition marked by an outpouching or bulging of the weakened sclera, the white outer layer of the eye, which is frequently accompanied by thinning and degeneration of the underlying uveal tissue. This condition...
Scleral melanocytosis is a benign ocular condition characterized by abnormal proliferation of melanocytes, or pigment-producing cells, within the sclera, the eye's white outer layer. This results in gray or blue-gray patches on the sclera. The condition is usually congenital,...
Scleral icterus is a medical condition in which the sclera, or white part of the eye, yellows as a result of elevated bilirubin levels in the blood. This yellow discoloration occurs when bilirubin, a byproduct of red blood cell...
Scleral ectasia is a rare, progressive ocular condition that causes the sclera, the eye's white outer layer, to thin and bulge. This condition can cause significant visual impairment and discomfort. The sclera supports and protects the eye, and any...
