Pediatric emergency medicine trisk 0575 0575
Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (102.26 KB, 1 trang )
Innervation of the conjunctiva and cornea comes from the first division of the
trigeminal nerve (V1). Abnormalities on the ocular surface may give rise to pain
or a foreign body sensation. The reflex arc that involves the afferent trigeminal
nerve and the efferent facial nerve results in a rapid blink, with contraction of the
orbicularis oculi muscle, to protect the surface of the eye in response to noxious
stimuli. Two other reactions to noxious stimuli may occur: tearing and discharge.
Epiphora or tearing may accompany virtually any conjunctival inflammation or
irritation. Tearing may even be a part of some forms of dry eye syndrome, as the
lacrimal gland attempts to compensate for a dry ocular surface. Discharge from
the eye results either from conjunctival exudation or precipitation of mucus out of
the tear film. The latter occurs when the tear film is not flowing smoothly such as
nasolacrimal duct obstruction, causing misinterpretation as infection when the
problem is actually mechanical. Although discharge may be a nonspecific
finding, the nature of the discharge may be helpful in the cause of an
inflammation or infection. The presence of membranes or pseudomembranes (
Fig. 27.1 ) is more common with adenovirus infection or Stevens–Johnson
syndrome. These white or white–yellow plaques are caused by loosely or firmly
adherent collections of inflammatory cells, cellular debris, and exudate.
EVALUATION AND DECISION
The approach to the child who presents to the emergency department with a red
eye is outlined in the flowchart shown in Figure 27.2 .
Any child with a red eye who wears contact lenses regularly, even if the lens is
not in the eye at the time of the examination, should be referred to an
ophthalmologist within 12 hours. Red, and often painful eyes of a person who
wears contact lenses may represent potentially blinding corneal infection (corneal
ulcer) or the breakdown of the corneal epithelium, which would predispose the
person to subsequent corneal infection. Contact lenses should be removed
immediately, further diagnostic or therapeutic interventions in these patients
should be performed with ophthalmology consultation. Decisions regarding
starting empiric antibiotic therapy should be made with the consultation of an
ophthalmologist, as there may be benefit to waiting until corneal cultures can be
obtained. The presence of a white spot on the cornea of a contact lens wearer with
inflamed conjunctiva is an ominous sign that may represent an ulcer ( Fig 27.3 ).
The absence of such a spot does not rule out corneal ulcer. Other causes of red
eye in a contact lens wearer include contact lens solution allergy (which may
develop even after years of using the same regimen), overwearing of contact
lenses, overly tight fit, foreign body, or a damaged contact lens. Examination by
