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Keratoconus (KC) is a disorder of the eye that results in progressive thinning of the cornea. This may result in blurry vision, double vision, nearsightedness, irregular astigmatism, and light sensitivity leading to poor quality-of-life. Usually both eyes are affected. In more severe cases a scarring or a circle may be seen within the cornea.
Eye surgery, also known as ophthalmic surgery or ocular surgery, is surgery performed on the eye or its adnexa. Eye surgery is part of ophthalmology and is performed by an ophthalmologist or eye surgeon. The eye is a fragile organ, and requires due care before, during, and after a surgical procedure to minimize or prevent further damage. An eye surgeon is responsible for selecting the appropriate surgical procedure for the patient, and for taking the necessary safety precautions. Mentions of eye surgery can be found in several ancient texts dating back as early as 1800 BC, with cataract treatment starting in the fifth century BC. It continues to be a widely practiced class of surgery, with various techniques having been developed for treating eye problems.
Dry eye syndrome, also known as keratoconjunctivitis sicca, is the condition of having dry eyes. Symptoms include dryness in the eye, irritation, redness, discharge, blurred vision, and easily fatigued eyes. Symptoms range from mild and occasional to severe and continuous. Dry eye syndrome can lead to blurred vision, instability of the tear film, increased risk of damage to the ocular surface such as scarring of the cornea, and changes in the eye including the neurosensory system.
Corneal transplantation, also known as corneal grafting, is a surgical procedure where a damaged or diseased cornea is replaced by donated corneal tissue. When the entire cornea is replaced it is known as penetrating keratoplasty and when only part of the cornea is replaced it is known as lamellar keratoplasty. Keratoplasty simply means surgery to the cornea. The graft is taken from a recently deceased individual with no known diseases or other factors that may affect the chance of survival of the donated tissue or the health of the recipient.
A corneal ulcer, or ulcerative keratitis, is an inflammatory condition of the cornea involving loss of its outer layer. It is very common in dogs and is sometimes seen in cats. In veterinary medicine, the term corneal ulcer is a generic name for any condition involving the loss of the outer layer of the cornea, and as such is used to describe conditions with both inflammatory and traumatic causes.
Acanthamoeba keratitis (AK) is a rare disease in which amoebae of the genus Acanthamoeba invade the clear portion of the front (cornea) of the eye. It affects roughly 100 people in the United States each year. Acanthamoeba are protozoa found nearly ubiquitously in soil and water and can cause infections of the skin, eyes, and central nervous system.
Buphthalmos is enlargement of the eyeball and is most commonly seen in infants and young children. It is sometimes referred to as buphthalmia. It usually appears in the newborn period or the first 3 months of life. and in most cases indicates the presence of congenital (infantile) glaucoma, which is a disorder in which elevated pressures within the eye lead to structural eye damage and vision loss.
Corneal neovascularization (CNV) is the in-growth of new blood vessels from the pericorneal plexus into avascular corneal tissue as a result of oxygen deprivation. Maintaining avascularity of the corneal stroma is an important aspect of healthy corneal physiology as it is required for corneal transparency and optimal vision. A decrease in corneal transparency causes visual acuity deterioration. Corneal tissue is avascular in nature and the presence of vascularization, which can be deep or superficial, is always pathologically related.
Corneal ulcer, also called keratitis, is an inflammatory or, more seriously, infective condition of the cornea involving disruption of its epithelial layer with involvement of the corneal stroma. It is a common condition in humans particularly in the tropics and in farming. In developing countries, children afflicted by vitamin A deficiency are at high risk for corneal ulcer and may become blind in both eyes persisting throughout life. In ophthalmology, a corneal ulcer usually refers to having an infection, while the term corneal abrasion refers more to a scratch injury.
Pellucid marginal degeneration (PMD) is a degenerative corneal condition, often confused with keratoconus. It typically presents with painless vision loss affecting both eyes. Rarely, it may cause acute vision loss with severe pain due to perforation of the cornea. It is typically characterized by a clear, bilateral thinning (ectasia) in the inferior and peripheral region of the cornea, although some cases affect only one eye. The cause of the disease remains unclear.
Keratoprosthesis is a surgical procedure where a diseased cornea is replaced with an artificial cornea. Traditionally, keratoprosthesis is recommended after a person has had a failure of one or more donor corneal transplants. More recently, a less invasive, non-penetrating artificial cornea has been developed which can be used in more routine cases of corneal blindness. While conventional cornea transplant uses donor tissue for transplant, an artificial cornea is used in the keratoprosthesis procedure. The surgery is performed to restore vision in patients with severely damaged cornea due to congenital birth defects, infections, injuries and burns.
The Seidel test is used to assess the presence of aqueous humor leakage from anterior chamber of the eye. Leakage may occur due to many corneal or scleral disorders, including corneal post-trauma, post-surgical leak, corneal perforation and corneal degeneration. Initially the test was used to detect aqueous humor leakage in postoperative patients, later it expanded to detect other causes or anterior chamber leakage.
Open-globe injuries are full-thickness eye-wall wounds requiring urgent diagnosis and treatment.
Post-LASIK ectasia is a condition similar to keratoconus where the cornea starts to bulge forwards at a variable time after LASIK, PRK, or SMILE corneal laser eye surgery. However, the physiological processes of post-LASIK ectasia seem to be different from keratoconus. The visible changes in the basal epithelial cell and anterior and posterior keratocytes linked with keratoconus were not observed in post-LASIK ectasia.
Corneal ectatic disorders or corneal ectasia are a group of uncommon, noninflammatory, eye disorders characterised by bilateral thinning of the central, paracentral, or peripheral cornea.
Neurotrophic keratitis (NK) is a degenerative disease of the cornea caused by damage of the trigeminal nerve, which results in impairment of corneal sensitivity, spontaneous corneal epithelium breakdown, poor corneal healing and development of corneal ulceration, melting and perforation. This is because, in addition to the primary sensory role, the nerve also plays a role maintaining the integrity of the cornea by supplying it with trophic factors and regulating tissue metabolism.
Phacolytic glaucoma (PG) is a form of glaucoma which is caused due to a leaking mature or immature cataract. Inflammatory glaucoma which occurs in phacolysis is a condition which is a result of the leakage of protein within the lens into the capsule of a mature or hyper mature cataract and involves a simple procedure to be cured that is referred to as cataract extraction.
Corneal opacification is a term used when the human cornea loses its transparency. The term corneal opacity is used particularly for the loss of transparency of cornea due to scarring. Transparency of the cornea is dependent on the uniform diameter and the regular spacing and arrangement of the collagen fibrils within the stroma. Alterations in the spacing of collagen fibrils in a variety of conditions including corneal edema, scars, and macular corneal dystrophy is clinically manifested as corneal opacity. The term corneal blindness is commonly used to describe blindness due to corneal opacity.
Exposure keratopathy is medical condition affecting the cornea of eyes. It can lead to corneal ulceration and permanent loss of vision due to corneal opacity.
Peripheral Ulcerative Keratitis (PUK) is a group of destructive inflammatory diseases involving the peripheral cornea in human eyes. The symptoms of PUK include pain, redness of the eyeball, photophobia, and decreased vision accompanied by distinctive signs of crescent-shaped damage of the cornea. The causes of this disease are broad, ranging from injuries, contamination of contact lenses, to association with other systemic conditions. PUK is associated with different ocular and systemic diseases. Mooren's ulcer is a common form of PUK. The majority of PUK is mediated by local or systemic immunological processes, which can lead to inflammation and eventually tissue damage. Standard PUK diagnostic test involves reviewing the medical history and a completing physical examinations. Two major treatments are the use of medications such as corticosteroids or other immunosuppressive agents and surgical resection of the conjunctiva. The prognosis of PUK is unclear with one study providing potential complications. PUK is a rare condition with an estimated incidence of 3 per million annually.
References
- ↑ Jinabhai, Amit; Radhakrishnan, Hema; o’Donnell, Clare (2011). "Pellucid corneal marginal degeneration: A review". Contact Lens and Anterior Eye. 34 (2): 56–63. doi:10.1016/j.clae.2010.11.007. PMID 21185225.