Prompt recognition and treatment of ophthalmic emergencies are crucial to prevention of unnecessary visual impairment. Although specific diagnosis may require specialist ophthalmic expertise, using simple guidelines non-ophthalmologists as well as ophthalmologists can identify patients requiring emergency or urgent evaluation. Intensity and duration of pain, rapidity of onset and severity of visual loss (primarily assessed by visual acuity, which should be measured for each eye in all patients presenting with ophthalmic emergencies), gross appearance of the globe, and abnormalities on ophthalmoscopy are particularly important parameters.
Excluding ocular and orbital trauma, which is covered in Chapter 19, this chapter reviews the common ophthalmic emergencies, for the most part grouped according to the predominant symptom. For each group, the section on triage highlight the features that are crucial during initial assessment by a non-ophthalmologist, for instance on presentation to an emergency department. The section on clinical assessment emphasizes what is important during ophthalmological evaluation. The management of the more common or important entities is then briefly discussed, principally to provide reference to discussion in other chapters.
The majority of patients with acute red eye have a relatively benign condition, such as bacterial, viral, or allergic conjunctivitis, subconjunctival hemorrhage, or blepharitis, which poses little or no threat to vision. Conversely a few are at risk of rapid progression within a few hours or days to severe visual impairment, even blindness, such as from acute angle closure glaucoma, intraocular infection (endophthalmitis), bacterial, viral, amebic, or fungal corneal infection, acute uveitis, or scleritis.
Emergency or urgent ophthalmic evaluation should be arranged for any patient with acute red eye and a history within the past few weeks of intraocular surgery, which predisposes to endophthalmitis; contact lens wear, which predisposes to corneal infection (see Figure 6–3); recent or distant history of corneal transplantation because of the possibility of graft rejection; previous episodes of acute uveitis or scleritis; or systemic diseases predisposing to uveitis or scleritis, such as ankylosing spondylitis and rheumatoid arthritis. In acutely ill patients, particularly those with sepsis or requiring prolonged intravenous cannulation such as in intensive therapy units or for parenteral nutrition, an acute red eye may be due to bacterial or fungal endophthalmitis (see Figure 15–32). Ocular involvement in toxic epidermal necrolysis, Stevens-Johnson syndrome, or erythema multiforme requires urgent ophthalmic assessment.
Pain, rather than discomfort, should be regarded as inconsistent with conjunctivitis, episcleritis, or blepharitis. It is suggestive of keratitis, intraocular or scleral inflammation, or elevated intraocular pressure, with the likelihood of a serious cause increasing with increasing severity. Associated nausea and vomiting are particularly suggestive of markedly elevated intraocular pressure. Deep, boring pain, typically waking the patient at night, is characteristic of scleritis. Photophobia characteristically occurs in keratitis and anterior uveitis.
Reduced vision, whether reported by the patient or identified by measurement ...