Pediatric emergency medicine trisk 0574 0574
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CHAPTER 27 ■ EYE: RED EYE
ATIMA DELANEY, BRUCE M. SCHNALL
INTRODUCTION
“Red eye” is a generic term that refers to any condition in which the “white of the
eye” appears red or pink. A red eye may be caused by local factors, intraocular
disease, or systemic problems. Tables 27.1 to 27.3 list common and lifethreatening causes of red eye. The cause of a red eye can often be identified by
the history alone. The history should include the presence or absence of pain,
foreign body sensation, itching, discharge, tearing, photophobia, onset, visual
disturbances, recent illnesses, and trauma. The examination should include visual
acuity, pupil shape and reactivity, the gross appearance of the sclera and
conjunctiva, extraocular muscle function, and palpation of preauricular nodes.
The evaluation often requires fluorescein staining and slit-lamp examination by
an experienced provider.
Discussion of chemical conjunctivitis or irritation caused by agents such as
smoke or trauma is limited here because the history often makes the diagnosis
clear. The management of these disorders is discussed in Chapters 114 Ocular
Trauma and 123 Ophthalmic Emergencies .
PATHOPHYSIOLOGY
The term conjunctivitis should be reserved for disorders in which the conjunctiva
is inflamed. Inflammation may be caused by direct irritation, infection,
abnormalities of underlying or contiguous structures (e.g., cornea), immune
phenomena, or secondary to abnormalities of the lid and lashes. Inflammation
within the anterior chamber affecting the iris (iritis) may also result in secondary
inflammation of the conjunctiva.
The sclera may become inflamed (scleritis). An intermediate layer, the
episclera, lies beneath the conjunctiva’s substantia propria and another largely
avascular fascial layer (Tenon fascia), where it is firmly attached to the sclera.
The episclera is more vascularized than the sclera and may become inflamed
either in a diffuse or localized fashion (diffuse, sectorial, or nodular episcleritis).
A tear film, which prevents desiccation, is constantly present over the surface
of the eye. A disruption in the function of the anatomic structures responsible for
producing the tear film may cause desiccation of the ocular surface, resulting in
irritation and inflammation (dry eye syndrome).
