THE PAINFUL RED EYE PART 1 DIAGNOSTIC APPROACH Lorrimer Esselaar

WHAT IS A PAINFUL RED EYE? In the context of The Painful Red Eye, pain means any form of discomfort from superficial mild burning and scratching to deep seated severe eye and orbital pain. REDNESS Significantly uncomfortable eyes are almost always red and vice versa. An apparent exception is the pain of sinusitis, which is deep seated and frequently localised to the eye or orbit. The commonest cause of eye pain without any eye signs is sinusitis. WHAT CONDITIONS ARE INCLUDED? The phrase The Painful Red Eye refers to 4 groups of conditions which cause discomfort or pain associated with widespread redness of the eye. Conjunctivitis Keratitis Anterior uveitis Acute angle closure glaucoma All these painful red eyes require urgent attention because some of these conditions can result in rapid and permanent loss of vision. Other causes of associated pain and redness are localised and therefore easy to recognise. They are not considered to be part of The Painful Red Eye group of conditions.

OCULAR EMERGENCIES There are only 4 Painful Red Eye ocular emergencies, one from each of the above 4 groups of conditions. Chemical burns Corneal abscess Open eye injuries Acute angle closure glaucoma The Primary Care Physician should: 1 Be able to recognise these immediately. 2 Be familiar with the necessary first aid and emergency management measures. 3 Know that they require immediate referral to an ophthalmologist thereafter.

HOW DO I APPROACH A PAINFUL RED EYE? REMEMBER THAT THERE ARE ONLY FOUR POSSIBILITIES Conjunctivitis Keratitis Anterior uveitis Acute angle closure glaucoma THREE IMPORTANT QUESTIONS MUST BE ANSWERED 1 Is there visual loss? No Yes Conjunctivitis. Keratitis, anterior uveitis, acute angle closure glaucoma. Remember that in a conjunctivitis, mucus in the tear film may float in front of the pupil and cause transient blurring of vision. If the patient blinks a few times the vision clears. 2 What is the pattern of the redness? Generalised Ciliary Conjunctivitis. Keratitis, anterior uveitis, acute angle closure glaucoma. Always evert the lower lid as this makes the pattern of redness more obvious.

conjunctival injection In conjunctivitis the pattern of redness is typically more intense towards the fornices and less intense towards the limbus. This pattern of redness is known as generalised conjunctival injection and is diagnostic of a conjunctivitis. It is nonspecific in that it does not distinguish different types of conjunctivitis. Compare the ciliary injection of keratitis, anterior uveitis and acute angle closure in which the redness is more intense around the limbus and less intense in the fornices. Generalised conjunctival injection 3 Could this be acute angle closure glaucoma? This is easy to answer because there is nothing else like it and the diagnosis can usually be made on the history alone. The loss of vision is severe, and the patient has acute onset, deep seated, intense, unilateral Ciliary injection eye pain radiating into the entire ipsilateral hemicranium, and which is so severe as to be accompanied by prostration, nausea and vomiting. The affected eye is bright red, the cornea is oedematous and the pupil is fixed and middilated. Yes No Acute angle closure glaucoma. Keratitis, anterior uveitis.

Questions 1 and 2 usually fairly reliably confirm or exclude a conjunctivitis. Acute angle closure glaucoma is unmistakable, but it is important to note that the redness is often so intense that that a ciliary pattern is not obvious. All that is needed now is to distinguish between a keratitis and an anterior uveitis. A careful inspection of the cornea will usually make it clear whether a keratitis is present. The only usual corneal signs in an anterior uveitis are keratic precipitates in the characteristic inferior triangular pattern. Any other corneal abnormalities are likely to indicate the presence of a keratitis. Keratic precipitates USE THE RED EYE TABLE Now use the features in the table which follows to confirm your diagnosis. Dendritic ulcer stained with fluorescein

DIFFERENTIAL DIAGNOSIS OF THE PAINFUL RED EYE

HELPFUL FEATURES PITFALLS PAIN The nature of the pain is helpful in localising the problem. Superficial pain usually results from surface problems and has the following characteristics: localised to the surface, burning, scratching, foreign body sensation. Deep pain usually results from intraocular, intraorbital or sinus problems and has the following characteristics: deep seated, aching and may be throbbing or constant. DISCHARGE Discharge is seldom the primary complaint, but it is very helpful in deciding whether a superficial problem is primarily infective, allergic or due to irritation. PITFALLS One difficulty is that there are occasional patients who do not fit neatly into one of the above groups. CONJUNCTIVITIS WITHOUT PAIN OR REDNESS Sometimes a low grade conjunctivitis is sufficient to produce a mild chronic discharge, but neither pain nor redness. It will not take you long to realise that this is just a painful red eye without pain or redness! KERATITIS OR ANTERIOR UVEITIS WITHOUT LOSS OF VISION Sometimes a localised peripheral keratitis like a dendritic ulcer or a mild anterior uveitis may not produce a loss of vision. Consequently you may initially mistake it for a conjunctivitis, but soon other features like ciliary injection or an obvious corneal lesion will alert you to your error.

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