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Emergency Physicians often approach the eye examination with apprehension. Eye complaints compose up to 10% of Emergency Department (ED) visits. A systematic approach to the eye examination can alleviate any discomfort and provide the basis for an accurate diagnosis and treatment.1-14 The most common ophthalmologic problems that present to an ED are infection, inflammation, injury, and visual disturbances.

A careful history will help guide the differential diagnosis and the physical examination. It must include a history of the presenting complaint, the mechanism of any injury, exposures to chemicals or infectious agents, baseline visual acuity, known ophthalmologic problems, baseline medical problems, current medications, and any known allergies. The eye examination progresses from the outside and works inward beginning with the visual acuity to assess the function of the eye. It is important to routinely inspect all anatomic structures of the eye regardless of the presenting eye complaint. Secondary problems (e.g., corneal lesions associated with conjunctivitis) may be missed if a complete and systemic examination is not performed on all patients.


The bony orbit is pyramidal in shape, surrounds the eye, and surrounds the associated neurovascular structures. The blood supply to the structures of the orbit originates from the ophthalmic artery. The anatomy of the eye and its surrounding soft tissue structures is demonstrated in Figure 185-1. A detailed discussion of the complex anatomy of the eye is beyond the scope of this chapter. The anatomy relevant to the eye examination will be discussed throughout this chapter.

FIGURE 185-1.

Anatomy of the eye and its surrounding soft tissues. A. Surface anatomy. B. Midsagittal section through the eye.


Visual acuity is referred to as the vital sign of the eyes. It provides a means for the functional assessment of this delicate sensory apparatus. Documentation of the visual acuity is essential when approaching a patient with eye complaints. Assess the patient’s visual acuity as soon as possible, preferably as part of the triage assessment, but at least as the primary assessment during physical exam. There are few exceptions to this rule. Chemical exposures to the eye require immediate irrigation to avoid potentially irreversible visual loss. Do not delay irrigation for visual acuity testing. Failure to document visual acuity is a common omission, may limit the differential diagnosis, and may have medicolegal ramifications.

Always test each eye individually and then both simultaneously. Test and document the visual acuity with the respective annotation to the right eye (OD), the left eye (OS), and both eyes (OU). Test the problematic eye first. Completely cover the eye not being tested. Light shining into the opposite eye may adversely affect the results of visual acuity testing. A list of commonly used abbreviations in the measurement of visual ...

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