Red eyes and red flags - when to refer

Glaucoma is an umbrella term used to describe a broad spectrum of conditions. Although it’s relatively rare, acute angle closure glaucoma is one of the few ophthalmic emergencies. It tends to happen to long sited patients (+ on their prescription) and occurs more often with age. Importantly, patients who previously had cataract surgery, do not get acute angle closure glaucoma. The fact that the natural lens has been taken out reverses anatomical changes that predispose them to angle closure glaucoma.

The key characteristics:

• Sudden increase in the pressure within one eye which becomes red and painful.
• Usually unilateral presentation.
• Acute or chronic history such as occasional glare and haloes around lights, especially at night when pupils are dilated.
• Sometimes associated gentle frontal headache, nausea or even abdominal pain.

The steamy or hazy cornea, as seen with a pen torch, suggests an increased eye pressure. Another way to identify an abnormally high eye pressure in the primary care setting is performing digital IOP test – gently touching both closed eyes with your fingers and determining which one feels firmer which can suggest a raised pressure.

If you suspect an angle closure, it needs an immediate referral.

It is a common condition and can have a unilateral or bi-lateral painful, photophobic red eye presentation. The patient may have been diagnosed with uveitis before and may even be under the care of an ophthalmologist for chronic uveitis. If this is the case, a recurring presentation is likely.

Other characteristics of uveitis:

• Symptoms non-resolving with OTC medication such as lubricants or antibiotics.
• Posterior synechiae - adhesions that are formed between adjacent structures within the eye and visible with a pen torch. They are indicative of previous or acute episodes of anterior uveitis, possibly inducing an irregular pupil.
• HLA B-27 positivity – in the history.
• Patient may be under Rheumatology for another systemic inflammatory disorder.

Gross assessment of vision will govern urgency of referral – it varies from immediate to the next day or two. Generally speaking, patients with worse vision and an inflamed looking eye need to be referred on a more acute basis.

Presentation can be very variable depending on the activity causing the trauma. Penetrating trauma could be quite subtle with complaints along the lines of ‘something went into my eye, my vision is not quite right’. Pain may or may not be involved.

The key questions to ask such patients:

• What exactly were they doing? Angle grinding is particularly dangerous.
• Were they wearing goggles? This does not exclude eye trauma.

Patients with a suspected penetrating trauma need to be referred to the eye emergency services.

Corneal foreign bodies, such as metallic, are difficult to efficiently and sufficiently remove without the slit lamp. Refer such patients to the urgent care clinic (same or next day) as well as treat them with some g. Chloramphenicol.

Penetrating injury cases with an obvious prolapse of an iris or orbital contents and gross vitreous loss such as in bottle injuries, require a same day urgent referral. All that really needs to be done in the primary care setting is to put an acrylic shield over their eye (don’t put any pressure pads on the eye) and speak to the local ophthalmology team.

With chemical injuries time is critical. If you can, irrigate the affected eye with a lot of saline (about a litre would be sufficient). Then send the patient on to a hospital eye service for onward management ASAP. Don’t forget to use a topical anaesthetic agent such as g. Proxymetacaine to provide pain relief and cooperation for the process of irrigation.

Thermal burns are usually managed as facial thermal injuries as airways can be involved. You will need to send such patients to a general emergency service that have ophthalmology cover.

Endophthalmitis is an infection of the eye involving all its tissue components, a rare but profound inflammatory response. This is an ophthalmic emergency that the primary care practitioner needs to be very cautious about.

Any patient presenting with an inflamed eye 7-10 days post cataract surgery needs to be urgently seen by the unit they’ve been operated on. Often patients get an improvement in vision after cataract surgery, and then all of a sudden, their vision drops and the eye becomes very red and painful.

Key symptoms:

• Pain
• Redness
• Photophobia
• Improvement in vision followed by loss of vision
• Day 7-10 post cataract surgery

These patients need urgent treatment as the bacterial load doubles every hour.

Retinal detachment is characterised by painless loss of vision, usually a unilateral presentation with no inflammatory signs. People with a history of myopia (short sightedness with a minus (-) prescription) are more at risk of a retinal detachment.

Key characteristics:

• Eye floaters - acute on chronic
• Flashing lights - “bolt of lightning”
• Sometimes patients report a dark shadow across their eye that comes and goes
• Normal or very poor central vision (depending on the degree of macula involvement)

Patients with suspected retinal detachment need to be referred to next available emergency eye clinic (within 24hours).