Keratoconjunctivitis is a term used to describe

inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

of both the

cornea The cornea is the transparency (optics), transparent front part of the eyeball which covers the Iris (anatomy), iris, pupil, and Anterior chamber of eyeball, anterior chamber. Along with the anterior chamber and Lens (anatomy), lens, the cornea ...

(the clear, front part of the eye) and the

conjunctiva In the anatomy of the eye, the conjunctiva (: conjunctivae) 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 gobl ...

(the thin, transparent membrane covering the white part of the eye and lining the inside of the eyelids). This condition can have various causes, and its presentation may vary depending on the underlying factors. When only the

is inflamed, it is called '' keratitis''; when only the

is inflamed, it is called ''

conjunctivitis Conjunctivitis, also known as pink eye or Madras eye, is inflammation of the conjunctiva, the thin, clear layer that covers the white surface of the eye and the inner eyelid. It makes the eye appear pink or reddish. Pain, burning, scratchiness ...

''. __TOC__

Causes

There are several potential causes of the inflammation: * Keratoconjunctivitis sicca 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" (VKC) is used to refer to keratoconjunctivitis occurring in spring, and is usually considered to be due to

allergen An allergen is an otherwise harmless substance that triggers an allergic reaction in sensitive individuals by stimulating an immune response. In technical terms, an allergen is an antigen that is capable of stimulating a type-I hypersensitivi ...

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 ...

. * " Adenoviral keratoconjunctivitis, also known as 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 t ...

infection. * " Infectious bovine keratoconjunctivitis" (IBK) is a disease affecting cattle caused by the bacteria '' Moraxella bovis''. * "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 non-human animals. The scope of veterinary medicine is wide, covering all animal species, both ...

concern, mostly caused by '' Chlamydophila pecorum.'' * " Superior limbic keratoconjunctivitis" is thought to be caused by mechanical trauma. * "Keratoconjunctivitis photoelectrica" ( arc eye) means inflammation caused by photoelectric UV light. It is a type of ultraviolet keratitis. Such UV exposure can be caused by arc

welding Welding is a fabrication (metal), fabrication process that joins materials, usually metals or thermoplastics, primarily by using high temperature to melting, melt the parts together and allow them to cool, causing Fusion welding, fusion. Co ...

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

Viral keratoconjunctivitis

Keratoconjunctivitis is frequently caused by viral infections in and around the eyes. A particularly common cause of this is the

herpes simplex virus Herpes simplex virus 1 and 2 (HSV-1 and HSV-2) are two members of the Herpesviridae#Human herpesvirus types, human ''Herpesviridae'' family, a set of viruses that produce Viral disease, viral infections in the majority of humans. Both HSV-1 a ...

. In some people, the infection may become chronic and keratoconjunctivitis may present during flare-ups of variable frequency. Over time, these can result in the corneas becoming progressively more opaque, leading to

blindness Visual or vision impairment (VI or VIP) is the partial or total inability of visual perception. In the absence of treatment such as corrective eyewear, assistive devices, and medical treatment, visual impairment may cause the individual difficul ...

References

External links

eMedicine – on Atopic keratoconjunctivitis

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