Mitch Medical Healthcare

Physical Examination

It is important to examine both eyes because many patients with conjunctivitis in one eye have clear signs of early conjunctivitis in the other. The type of infection must be closely

Visual axis

Anterior chamber Posterior chamber Ciliary process

Zonule of Zinn

Lens

Vitreous

Optic papilla Optic cup

Central artery

Optic axis

Cornea Iris

Visual axis

Optic axis

Cornea Iris

Vitreous

Pars optica retinae

Optic papilla Optic cup

Central artery

Choroidea

-Sheath NOptic nerve

Canal of Schlemm or sinus venosus

Conjunctiva bulbi

Ciliary muscle

Pars ciliaris retinae

Ora serrata Equator

Pars optica retinae

Choroidea

Sclera Fovea centralis

-Sheath NOptic nerve

Figure 41-1 Anatomy of the right eyeball. (From Scheie HG, Albert DM. Textbook of Ophthalmology, 9th ed. Philadelphia, Saunders, 1977.)

Table 41-1 Red Eye: Differential Diagnosis

Parameter	Conjunctivitis, Bacterial	Iritis	Keratitis	Acute Glaucoma
Vision	Normal	Blurred	Blurred	Marked blurring
Pain	None	Moderately severe; intermittent stabbing	Sharp, severe	Severe; sometimes nausea/ vomiting
Photophobia	None	Moderate	Moderate	Moderate
Discharge	Usually significant with crusting of lashes	None	None to mild	None
Conjunctival injection	Diffuse	Circumcorneal	Circumcorneal	Diffuse
Appearance of cornea	Clear	Clear	Cloudy	Cloudy
Pupil size	Normal	Constricted	Normal	Dilated
Intraocular pressure*	Normal	Normal or low	Normal	Elevated
From American Academy of Ophthalmology. The Red Eye. AAO Professional Information Committee, San Francisco, *Caution: Do not measure IOP with discharge present.			9 co

inspected; conjunctival infection is characterized by individually visible vessels in the conjunctiva branching from the sclera toward the cornea, whereas ciliary infection appears as a red ring surrounding the cornea in which individual vessels are not clearly visible. The significance of ciliary infection is that the deep ciliary vessels are involved, indicating a much more serious inflammatory condition of the eye, such as a deep corneal infection, iritis, or iridocyclitis. Inspect the palpebral conjunctiva carefully with magnification to determine whether lymphoid hyperplasia (cobblestone appearance) exists. The type and quantity of discharge are assessed by pulling down the lower lid. The appearance of the punctum should be examined to determine whether pus is coming out of the tear duct. Palpation of the tear sac on the upper portion of the nose (lacrimal crest) demonstrates tenderness in cases of acute dacryocystitis.

Carefully examine the cornea. Normally, the cornea is perfectly transparent. Excessive fluid within the stroma of the cornea results in partial opacification that can be observed by direct illumination with a penlight. A diffuse corneal haze can occur with congenital glaucoma and angle-closure glaucoma. After inspection with a penlight under magnification, perform corneal staining with fluores-cein using sterile filter paper strips. The stained part of the strip is moistened with water and touched to the conjunctiva away from the cornea. With blinking, the fluorescein

Box 41-1 Approach to Patient Presenting with Red Eye (No History of Trauma)

1. Check for the following symptoms or signs.

a. Reduced vision b. Pain c. Photophobia d. Corneal staining e. Corneal edema f. Unequal pupils g. Elevated intraocular pressure

2. Refer to ophthalmologist if any of these signals are present.

3. If none of the above is present, the diagnosis is probably conjunctivitis.

4. The triad of a red eye, pain, and loss of vision should always alert the examiner to a potentially blinding condition.

Table 41-2 Conjunctivitis Clues spreads over the cornea. A UV light source enhances fluorescence. Areas of bright-green staining denote absent or diseased epithelium. Corneal staining readily demonstrates a corneal abrasion and helps identify corneal foreign bodies and infectious epithelial defects, such as herpetic dendritic keratitis (Fig. 41-2).

Examine the pupils carefully for size and shape. In most people the pupils are of equal size; a small percentage have congenital variation in the size of the pupils (anisocoria). These patients are often aware that their pupils are unequal. In patients with previously equal pupils, inequality of the pupil may indicate iritis, typically with the affected pupil partially constricted. In acute angle-closure glaucoma the pupil is usually partially dilated and may not be round. Unequal pupil size is an important sign of significant ocular trauma or third nerve palsies.

Estimate the anterior chamber depth by side illumination with a penlight. If the anterior chamber is normal or deep, the entire surface of the iris is well illuminated. When the anterior chamber is shallow, the iris on the more distant side of the pupil is in shadow. A shallow anterior chamber in a red eye may indicate acute angle-closure glaucoma or ocular trauma. The anterior chamber appears deep in patients with congenital glaucoma.

If the red eye does not have an obvious infection, measure the intraocular pressure (IOP) with a tonometer. IOP is normal in most patients with red eye, except for those with acute angle-closure glaucoma. With iritis and traumatic, perforating ocular injuries, IOP is generally low. Sterilize the tonometer before and after application to a red eye, preferably by heat sterilization.

Preauricular lymph node enlargement is a frequent sign of viral conjunctivitis and usually is not present with acute bacterial conjunctivitis (see Table 41-2).

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