Keratoconjunctivitis is

inflammation Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...

("-itis") of the

cornea The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical power ...

and

conjunctiva The conjunctiva is a thin mucous membrane that lines the inside of the eyelids and covers the sclera (the white of the eye). It is composed of non-keratinized, stratified squamous epithelium with goblet cells, stratified columnar epithelium ...

. When only the

is inflamed, it is called ''

keratitis Keratitis is a condition in which the eye's cornea, the clear dome on the front surface of the eye, becomes inflamed. The condition is often marked by moderate to intense pain and usually involves any of the following symptoms: pain, impaired e ...

''; when only the

is inflamed, it is called ''

conjunctivitis Conjunctivitis, also known as pink eye, is inflammation of the conjunctiva, outermost layer of the white part of the eye and the inner surface of the eyelid. It makes the eye appear pink or reddish. Pain, burning, scratchiness, or itchiness may ...

''.

Causes

There are several potential causes of the inflammation: *

Keratoconjunctivitis sicca Dry eye syndrome (DES), also known as keratoconjunctivitis sicca (KCS), is the condition of having dry eyes. Other associated symptoms include irritation, redness, discharge, and easily fatigued eyes. Blurred vision may also occur. Symptoms range ...

is used when the inflammation is due to dryness. ("Sicca" means "dryness" in medical contexts.) It occurs with 20% of rheumatoid arthritis patients. * The term "

vernal keratoconjunctivitis Vernal keratoconjunctivitis (VKC, also Spring catarrh, Vernal catarrh or Warm weather conjunctivitis) is a recurrent, bilateral, and self-limiting type of conjunctivitis (pink eye) having a periodic seasonal incidence. Vernal keratopathy Corneal ...

" (VKC) is used to refer to keratoconjunctivitis occurring in

spring Spring(s) may refer to: Common uses * Spring (season), a season of the year * Spring (device), a mechanical device that stores energy * Spring (hydrology), a natural source of water * Spring (mathematics), a geometric surface in the shape of a ...

, and is usually considered to be due to

allergen An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies. In technical terms ...

s. * "Atopic keratoconjunctivitis" is one manifestation of

atopy Atopy is the tendency to produce an exaggerated immunoglobulin E (IgE) immune response to otherwise harmless substances in the environment. Allergic diseases are clinical manifestations of such inappropriate, atopic responses. Atopy may have a ...

. * "Epidemic keratoconjunctivitis" is caused by an

adenovirus Adenoviruses (members of the family ''Adenoviridae'') are medium-sized (90–100 nm), nonenveloped (without an outer lipid bilayer) viruses with an icosahedral nucleocapsid containing a double-stranded DNA genome. Their name derives from the ...

infection. * "

Infectious bovine keratoconjunctivitis Infectious bovine keratoconjunctivitis (IBK), also known as pinkeye, New Forest eye or blight,Farming Small Areas, August/September, 2008, "Clearing up pinkeye" is a veterinary infection of cattle caused by ''Moraxella bovis'', a Gram-negative, β-h ...

" (IBK) is a disease affecting cattle caused by the bacteria ''

Moraxella bovis ''Moraxella bovis'' is a Gram-negative, aerobic, oxidase-positive rod-shaped bacterium. It is the cause of infectious bovine keratoconjunctivitis, a contagious ocular disease of cattle,George M. Garrity: '' Bergey's Manual of Systematic Bacterio ...

''. * "Pink eye in sheep and goat" is another infectious keratoconjunctivitis of

veterinary Veterinary medicine is the branch of medicine that deals with the prevention, management, diagnosis, and treatment of disease, disorder, and injury in animals. Along with this, it deals with animal rearing, husbandry, breeding, research on nutri ...

concern, mostly caused by ''

Chlamydophila pecorum ''Chlamydia pecorum'', also known as Chlamydophila pecorum is a species of Chlamydiaceae that originated from ruminants, such as cattle, sheep and goats. It has also infected koalas and swine. ''C. pecorum'' strains are serologically and patho ...

.'' * "

Superior limbic keratoconjunctivitis Superior limbic keratoconjunctivitis (SLK, Théodore's syndrome) is a disease of the eye characterized by episodes of recurrent inflammation of the superior cornea and limbus, as well as of the superior tarsal and bulbar conjunctiva. It was first ...

" is thought to be caused by mechanical trauma. * "Keratoconjunctivitis photoelectrica" (

arc eye Photokeratitis or ultraviolet keratitis is a painful eye condition caused by exposure of insufficiently protected eyes to the ultraviolet (UV) rays from either natural (e.g. intense sunlight) or artificial (e.g. the electric arc during welding) ...

) means inflammation caused by photoelectric UV light. It is a type of

ultraviolet keratitis Photokeratitis or ultraviolet keratitis is a painful eye condition caused by exposure of insufficiently protected eyes to the ultraviolet (UV) rays from either natural (e.g. intense sunlight) or artificial (e.g. the electric arc during welding) ...

. Such UV exposure can be caused by arc

welding Welding is a fabrication (metal), fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, causing Fusion welding, fusion. Welding is distinct from lower ...

without wearing protective eye glass, or by high altitude exposure from sunlight reflected from snow ("

snow blindness Photokeratitis or ultraviolet keratitis is a painful eye condition caused by exposure of insufficiently protected eyes to the ultraviolet (UV) rays from either natural (e.g. intense sunlight) or artificial (e.g. the electric arc during welding) ...

"). The inflammation will only appear after about 6 to 12 hours. It can be treated by rest, as the inflammation usually heals after 24–48 hours. Proper eye protection should be worn to prevent keratoconjunctivitis photoelectrica.

References

External links

eMedicine – on Atopic keratoconjunctivitis

Inflammations Disorders of sclera and cornea Disorders of conjunctiva {{eye-stub