eye disorders
Red Eye
Evaluation of Red Eye
Most disorders can be diagnosed by a general health care professional. History of present illnessshould note the onset and duration of redness and presence of any change in vision, itching, scratchy sensation, pain, or discharge. Nature and severity of pain, including whether pain is worsened by light (photophobia), are noted. The clinician should determine whether discharge is watery or purulent. Other questions assess history of injury, including exposure to irritants and use of contact lenses (eg, possible overuse, such as wearing them while sleeping). Prior episodes of eye pain or redness and their time patterns are elicited. should seek symptoms suggesting possible causes, including headache, nausea, vomiting, and halos around lights ( Angle-Closure Glaucoma ); runny nose and sneezing (allergies, upper respiratory infection); and cough, sore throat, and malaise (upper respiratory infection). Past medical historyincludes questions about known allergies and autoimmune disorders. Medication history should specifically ask about recent use of topical ophthalmic medications (including over-the-counter medications), which might be sensitizing. General examination should include head and neck examination for signs of associated disorders (eg, upper respiratory infection, allergic rhinitis, zoster rash). Eye examination involves a formal measure of visual acuity and usually requires a penlight,fluoresceinstain, and slit lamp. Best corrected visual acuity is measured. Pupillary size and reactivity to light are assessed. True photophobia (sometimes called consensual photophobia) is present if shining light into an unaffected eye causes pain in the affected eye when the affected eye is shut. Extraocular movements are assessed, and the eye and periorbital tissues are inspected for lesions and swelling. The tarsal surface is inspected for papillae. The corneas are stained withfluoresceinand examined with magnification. If a corneal abrasion is found, the eyelid is everted and examined for hidden foreign bodies. Inspection of the ocular structures and cornea is best done using a slit lamp. A slit lamp is also used to examine the anterior chamber for cells, flare, and pus (hypopyon). Ocular pressure is measured using tonometry, although it may be permissible to omit this test if there are no symptoms or signs suggesting a disorder other than conjunctivitis. The following findings are of particular concern: Sudden, severe pain and vomiting Zoster rash Decreased visual acuity Corneal crater Branching, dendritic corneal lesion Ocular pressure>40 mm Hg Failure to blanch withphenylephrineeye drop are differentiated from other causes of red eye by the absence of pain, photophobia, and corneal staining. Among these disorders, Episcleritis is differentiated by its focality, and subconjunctival hemorrhage is usually differentiated by the absence of lacrimation, itching, and photosensitivity. Clinical criteria do not accurately differentiate viral from bacterial conjunctivitis. instillation, completely relieves pain, the cause is probably limited to the cornea. If pain is present and is not relieved by an ocular anesthetic, the cause may be Overview of Uveitis , Anterior uveitis, acute angle-closure glaucoma, and scleritiscan usually be differentiated from other causes of red eye by the presence of pain and the absence of corneal staining. Anterior uveitis is likely in patients with pain, true photophobia, absence of cornealfluoresceinstaining, and normal intraocular pressure; it is definitively diagnosed based on the presence of cells and flare in the anterior chamber. However, these findings may be difficult for general health care practitioners to discern. Acute angle-closure glaucoma can usually be recognized by the sudden onset of its severe and characteristic symptoms, but tonometry is definitive. If pain persists despite an ocular anesthetic in a patient with a normalfluoresceinexamination, consider anterior uveitis, scleritis, or acute angle-closure glaucoma. 2.5% causes blanching in a red eye unless the cause is Scleritis . Suspected acute Angle-Closure Glaucoma None A history of angle-closure glaucoma A narrow anterior chamber Testing is usually unnecessary. Viral cultures may help if Herpes Simplex Virus (HSV) Infections or 