ORBITAL DISCHARGE
ORBITAL DISCHARGE: Excerpt from Differential Diagnosis in Primary Care
A clear or purulent discharge from the eye is usually due to allergy or
infection, but a few notable exceptions exist. In addition to using
anatomy to formulate the list of diagnostic possibilities, it is
well to apply the mnemonic MINT to the various anatomic components.
Beginning with the eyelids, one should recall the following:
M—Malformations like a chalazion, ectropion, and entropion
I—Inflammatory conditions like blepharitis, a hordeolum (stye),
and allergic or infectious conjunctivitis
N—Neoplasms such as squamous cell carcinoma and angioma
T—Traumatic conditions, especially foreign bodies
The nasolacrimal duct may become inflamed and obstructed
(dacryocystitis). The bulbar conjuctiva may be involved by
malformations like a pterygium or a pinguecula and cause a clear discharge.
Inflammatory and traumatic conditions here are similar to those of the
palpebral conjunctiva. It is well to mention toxic causes of a nonbloody
discharge, such as irritation from tobacco smoke, cold, and irritating
gases; chronic alcoholism, arsenic poisoning, and iodism may cause a clear
discharge.
Separating the eyeball into its various components, one recalls the
cornea and immediately one should think of a foreign body of the
cornea or of a laceration, a keratitis, and malformations like keratoconus.
Next, the iris suggests iritis as a cause of discharge, but by
using the mnemonic one will not forget albinism as a cause of excessive
tearing. In addition, the iris angle should remind one of acute glaucoma,
which often presents with lacrimation as well as with pain. The
lens should suggest refractive errors as a major cause of a clear
discharge and predisposition to infection of the lids. Finally, the
sclera is the site of episcleritis and scleritis, which are
frequently associated with a nonbloody discharge.
Turning to the lacrimal gland, one should remember mumps of this
gland and other infections. The vascular supply to the eye should
suggest the tearful discharge of histamine cephalalgia and obstruction of
the venous drainage by a cavernous sinus thrombosis. Paralysis of the
muscles of the eye, especially the facial nerve, creates a
discharge by excessive exposure to dust and air.
Approach to the Diagnosis
Anatomy has served us well in developing a differential, although the
cause of a discharge from the eye is often easy to establish. Foreign
bodies, trauma, toxins, and conjunctivitis are the conditions most commonly
responsible. This is why in the approach to the diagnosis one will first
examine the eye carefully under magnification and use fluorescein to rule
out a foreign body or laceration. Then, a careful history of exposure to
toxins (e.g., industrial) is in order. Finally, if the discharge is
unilateral, a smear and culture of specific bacteria are valuable before
treatment. If it is bilateral, allergy should be considered, as well as
refractive errors. Tonometry should be performed. Referral to an
ophthalmologist may be appropriate at any one of these stages (when in
doubt, refer it out).
Other Useful Tests
-
Complete blood count (CBC) and differential
- Sedimentation rate
- Urinalysis
- Smear and culture of discharge
- Venereal disease research laboratory (VDRL) test
- Tuberculin test
- Antinuclear antibody (ANA) test (uveitis)
- Smear for eosinophils (allergic conjunctivitis)
- Tonometry (glaucoma)
- Refraction
- Thyroid function test (Graves disease)
- Visual fields
- X-ray of skull
- X-ray of sinuses (acute sinusitis)
- Sonogram
- Computed tomography (CT) scan (orbital tumor)
- Biopsy
- Exploratory surgery
- Mumps skin test
- Histamine test (histamine cephalalgia)
Pictures
Book Source Details
- Book Title: Differential Diagnosis in Primary Care
- Author(s): R. Douglas Collins MD, FACP
- Year of Publication: 2007
- Copyright Details: Differential Diagnosis in Primary Care, Copyright © 2007 Lippincott Williams & Wilkins.
More About Urethritis
More Medical Textbooks Online about Urethritis
Review other book chapters online related to Urethritis:
Medical Books Excerpts
- Urethral Discharge
- "The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter" (2000)
- [ read ]
- Vaginal Discharge
- "The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter" (2000)
- [ read ]
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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