出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/02/24 01:54:18」(JST)
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| Red eye (medicine) | |
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| Classification and external resources | |
Subconjunctival hemorrhage causing red coloration as result of ruptured blood vessel in the eye.
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| ICD-10 | H57.9 |
| ICD-9 | 379.93 |
| DiseasesDB | 18665 |
In medicine, red eye is a non-specific term to describe an eye that appears red due to illness or injury. The term usually refers to injection and prominence of the superficial blood vessels of the conjunctiva, or sclera, which may be caused by disorders of these or adjacent structures. Conjunctivitis and subconjunctival hemorrhage are two of the less serious but more common causes.
Management includes assessing whether emergent action (including referral) is needed, or whether treatment can be accomplished without additional resources.
Slit lamp examination is invaluable in diagnosis but initial assessment can be performed using a careful history, testing vision (visual acuity), and carrying out a penlight examination.
Of the many causes, conjunctivitis is the most common.[1] Others include:
Usually nonurgent
Usually urgent
Particular signs and symptoms[1] may indicate that the cause is serious and requires immediate attention.
Six such signs are:
Visual acuity
A reduction in visual acuity in a 'red eye' is indicative of serious ocular disease,[11] such as keratitis, iridocyclitis, and glaucoma, and never occurs in simple conjunctivitis without accompanying corneal involvement.
Ciliary flush
Ciliary flush is usually present in eyes with corneal inflammation, iridocyclitis or acute glaucoma, though not simple conjunctivitis. A ciliary flush is a ring of red or violet spreading out from around the cornea of the eye.
Corneal abnormalities
The cornea requires to be transparent to transmit light to the retina. Because of injury, infection or inflammation, an area of opacity may develop which can be seen with a penlight or ophthalmoscope. In rare instances, this opacity is congenital.[12] In some, there is a family history of corneal growth disorders which may be progressive with age. Much more commonly, misuse of contact lenses may be a precipitating factor. Whichever, it is always potentially serious and sometimes necessitates urgent treatment and corneal opacities are the fourth leading cause of blindness. Opacities may be keratic, that is, due to the deposition of inflammatory cells, hazy, usually from corneal edema, or they may be localized in the case of corneal ulcer or keratitis.
Corneal epithelial disruptions may be detected with fluorescein staining of the eye, and careful observation with cobalt-blue light. Corneal epithelial disruptions would stain green, which represents some injury of the corneal epithelium. These types of disruptions may be due to corneal inflammations or physical trauma to the cornea, such as a foreign body.
Pupillary abnormalities
In an eye with iridocyclitis, (inflammation of both the iris and ciliary body), the involved pupil will be smaller than the uninvolved, due to reflex muscle spasm of the sphincter muscle of the iris. Generally, conjunctivitis does not affect the pupils. With acute angle-closure glaucoma, the pupil is generally fixed in mid-position, oval, and responds sluggishly to light, if at all.
Shallow anterior chamber depth may indicate a predisposition to one form of glaucoma (narrow angle) but requires slit-lamp examination or other special techniques to determine it. In the presence of a "red eye", a shallow anterior chamber may indicate acute glaucoma, which requires immediate attention.
Abnormal intraocular pressure
Intraocular pressure should be measured as part of the routine eye examination. It is usually only elevated by iridocyclitis or acute-closure glaucoma, but not by relatively benign conditions. In iritis and traumatic perforating ocular injuries, the intraocular pressure is usually low.
Three symptoms in particular require prompt and careful attention:
Blurry vision
Blurry vision often indicates serious ocular disease. However, if the blurriness improves with blinking, it suggests ocular surface discharge of some variety. Coloured halos are an indication of corneal edema, and are a warning that acute glaucoma may be present.
Severe pain
Those with conjunctivitis may report mild irritation or scratchiness, but never extreme pain, which is an indicator of more serious disease such as keratitis, corneal ulceration, iridocyclitis, or acute glaucoma.
Photophobia
Photophobia (intolerance to light) is most characteristic of iritis and injury to the cornea, but may also be present in acute glaucoma (angle closure type).
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| リンク元 | 「毛様充血」 |
| 関連記事 | 「ciliary」「hyperemia」「cilia」 |