Redness may be due to hyperemia of the conjunctival, ciliary, or episcleral vessels; erythema of the eyelids; or subconjunctival hemorrhage (eFigure 7–1). The major differential diagnoses are conjunctivitis, corneal disorders, acute glaucoma, and acute uveitis (see Table 7–1).
Spontaneous subconjunctival hemorrhage while receiving warfarin. (From the University of California, Davis, Cornea and External Diseases. Reproduced, with permission, from Riordan-Eva P, Augsburger JJ. Vaughan & Asbury's General Ophthalmology, 19th ed. McGraw-Hill, 2018.)
Table 7–1.The inflamed eye: differential diagnosis of common causes. ||Download (.pdf) Table 7–1. The inflamed eye: differential diagnosis of common causes.
| ||Acute Conjunctivitis ||Acute Anterior Uveitis (Iritis) ||Acute Angle-Closure Glaucoma ||Corneal Trauma or Infection |
|Incidence ||Extremely common ||Common ||Uncommon ||Common |
|Discharge ||Moderate to copious ||None ||None ||Watery or purulent |
|Vision ||No effect on vision ||Often blurred ||Markedly blurred ||Usually blurred |
|Pain ||Mild ||Moderate ||Severe ||Moderate to severe |
|Conjunctival injection ||Diffuse ||Mainly circumcorneal ||Mainly circumcorneal ||Mainly circumcorneal |
|Cornea ||Clear ||Usually clear ||Cloudy ||Clarity change related to cause |
|Pupil size ||Normal ||Small ||Moderately dilated ||Normal or small |
|Pupillary light response ||Normal ||Poor ||None ||Normal |
|Intraocular pressure ||Normal ||Usually normal but may be elevated ||Markedly elevated ||Normal |
|Smear ||Causative organisms ||No organisms ||No organisms ||Organisms found only in corneal infection |
et al. Red eye: a guide for non-specialists. Dtsch Arztebl Int. 2017;114:302.
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Ocular pain may be caused by trauma, infection, inflammation, or rapid or marked increase in intraocular pressure.
Foreign body sensation may be due to corneal or conjunctival foreign bodies, disturbance of the corneal epithelium, or rubbing of eyelashes against the cornea (trichiasis).
Photophobia is usually due to corneal inflammation (keratitis) or anterior uveitis (iritis). Other causes are albinism, aniridia, cone dystrophy, or fever associated with various systemic infections.
Itching is characteristically associated with allergic eye disease.
Scratching and burning from dryness of the eyes may be due to lacrimal gland hypofunction, secondary to systemic disorders (eg, Sjögren disease) or drugs (eg, atropine-like agents); ocular surface disease; or dry environment.
Watering is usually due to inadequate tear drainage through obstruction of the lacrimal drainage system or malposition of the lower lid. Reflex tearing occurs with any disturbance of the corneal epithelium. Overflow of tears onto the face is termed epiphora.
AY. The etiology of epiphora: a multifactorial issue. Semin Ophthalmol. 2016;31:275.