Stickler Syndrome is a hereditary connective tissue disorder that affects several systems in the body, including the eyes, ears, skeleton, and craniofacial structures. Stickler Syndrome, named after pediatrician Dr. Gunnar B. Stickler, who described the condition in 1965, is...
Stevens-Johnson Syndrome (SJS) is a serious, potentially fatal condition that primarily affects the skin and mucous membranes, including the eyes. It is distinguished by a hypersensitive reaction that can be induced by a variety of medications, infections, or other...
Squamous cell carcinoma (SCC) of the eyelid is a malignant tumor caused by squamous cells, which are flat, thin cells found in the epidermis, or outermost layer of skin. This type of skin cancer is the second most common...
What is Solar Retinopathy (SR)?
Solar retinopathy is an ocular condition caused by direct exposure of the retina to intense sunlight, especially when viewing the sun without proper eye protection. This condition is most commonly associated with solar eclipses, in...
Sjögren's syndrome is a chronic autoimmune disease characterized by lymphocytic infiltration and destruction of exocrine glands, particularly the salivary and lacrimal glands, which causes dry mouth (xerostomia) and dry eyes (keratoconjunctivitis sicca). Although Sjögren's syndrome can affect multiple organs,...
Sickle cell retinopathy is a vision-threatening complication of sickle cell disease (SCD), a genetic disorder that alters the structure and function of hemoglobin, the protein in red blood cells that transports oxygen throughout the body. In sickle cell disease,...
Serpiginous choroiditis, also known as serpiginous chorioretinopathy, is a rare, chronic, and progressive inflammatory disease affecting the choroid and retinal pigment epithelium (RPE) of the eye. Serpentine or snake-like lesions spread from the optic disc across the retina, causing...
What is secondary glaucoma?
Secondary glaucoma is a broad category of eye conditions distinguished by elevated intraocular pressure (IOP) due to a known cause or underlying pathology. Secondary glaucoma, as opposed to primary glaucoma, usually develops as a result of...
What is secondary cataract?
Secondary cataract, also known as posterior capsule opacification (PCO), is a common complication that can develop following cataract surgery. While the term "secondary cataract" may imply the formation of a new cataract, it actually refers to...
Definition of Secondary Acquired Lacrimal Duct Obstruction
Secondary acquired lacrimal duct obstruction (SALDO) is a condition in which the lacrimal drainage system becomes clogged due to external factors such as trauma, surgery, inflammation, infection, or tumors. In contrast to primary...
Sebaceous gland carcinoma (SGC) is a rare and aggressive malignancy that originates in the sebaceous glands and most commonly affects the periocular region. While sebaceous glands exist throughout the body, they are most concentrated around the eyes, where they...
What is scleromalacia perforans?
Scleromalacia perforans is a rare but severe ocular condition that causes progressive thinning and degeneration of the sclera, the eye's white outer coating. This condition is most commonly linked to long-term, poorly controlled systemic autoimmune diseases,...
What is scleritis?
Scleritis is a serious and potentially blinding inflammatory condition affecting the sclera, the white outer coat of the eye. Unlike more superficial eye inflammations, such as episcleritis, scleritis affects deeper layers of the sclera and, if untreated,...
What is Scleral Staphyloma?
Scleral staphyloma is a rare and serious ocular condition characterized by the abnormal thinning and outward bulging of the sclera, the white, tough outer layer of the eye. This condition results in the formation of a...
Scleral melanocytosis is a rare, benign ocular condition characterized by the presence of slate-gray or bluish pigmentation on the sclera, the white part of the eye. This pigmentation results from an increased number of melanocytes, the cells responsible for...
Scleral icterus, commonly referred to as jaundice of the eyes, is a clinical sign characterized by the yellow discoloration of the sclera—the white part of the eye. This yellowing is due to the accumulation of bilirubin, a yellow pigment...
Scleral ectasia is a rare and serious ocular condition characterized by the abnormal thinning and outward bulging of the sclera, the white, tough, outer layer of the eye that provides structural support and protection. This condition can lead to...
Sarcoidosis is a complex, multisystem inflammatory disease characterized by the formation of tiny clumps of inflammatory cells called granulomas. These granulomas can form in virtually any organ of the body, but they most commonly affect the lungs, lymph nodes,...
What is Retinoschisis?
Retinoschisis is an ocular condition characterized by the splitting of the retina, the light-sensitive layer of tissue located at the back of the eye. The retina is essential for vision, as it captures visual information and transmits...
Retinopathy of Prematurity (ROP) is a potentially blinding eye disorder that primarily affects premature infants, particularly those born before 31 weeks of gestation and with a birth weight of less than 2.75 pounds (1250 grams). ROP is a disease...
Retinoblastoma is a rare and aggressive form of eye cancer that originates in the retina, the light-sensitive layer of tissue located at the back of the eye. The retina is responsible for capturing visual images and sending them to...
What is retinitis?
Retinitis is a group of inflammatory conditions that affect the retina, the light-sensitive layer in the back of the eye that captures visual information and transmits it to the brain via the optic nerve. The retina is...
Retinitis Pigmentosa (RP) is a group of inherited retinal dystrophies characterized by progressive degeneration of the retina's photoreceptor cells, particularly the rods and cones. These photoreceptor cells are responsible for converting light into electrical signals that the brain interprets...
Retinal vein occlusion (RVO) is a common and potentially vision-threatening ocular condition that occurs when one of the veins that transport blood away from the retina becomes clogged. The retina is the light-sensitive layer at the back of the...
Retinal telangiectasia, also known as macular telangiectasia, is a rare, progressive retinal disorder characterized by abnormal dilation and leakage of retinal blood vessels, particularly in the macula, the central part of the retina that is responsible for sharp, detailed...
What is retinal detachment?
Retinal detachment is a serious and potentially blinding ocular condition in which the retina, a thin layer of tissue at the back of the eye, separates from the surrounding supportive tissue. The retina detects light and...
Retinal astrocytic hamartoma is a rare, benign retinal tumor that develops from astrocytes, which are a type of glial cell within the retina. These tumors are usually non-cancerous and linked to genetic conditions, particularly tuberous sclerosis complex (TSC) and,...
Retinal artery occlusion (RAO) is a serious and potentially vision-threatening ocular condition that occurs when the blood supply to the retina is suddenly cut off, resulting in ischemia (lack of blood flow) and subsequent damage to retinal tissue. The...
What is recurrent corneal erosion?
Recurrent corneal erosion (RCE) is a painful and often debilitating ocular condition characterized by repeated breakdown or detachment of the corneal epithelium, the cornea's outermost layer. The cornea is the eye's transparent, dome-shaped surface that...
Radiation cataract is a type of cataract caused by exposure to ionizing radiation. Unlike the more common age-related cataracts, which develop gradually as a result of the natural aging process, radiation cataracts are caused by external factors—specifically, exposure to...
