Of all the organs of the body, the eye is most accessible to direct examination. Visual function can be quantified by simple subjective testing. The external anatomy of the eye is visible to inspection with the unaided eye and with fairly simple instruments. With more complicated instruments, the interior of the eye is visible through the clear cornea. The eye is the only part of the body where blood vessels and central nervous system tissue (retina and optic nerve) can be viewed directly. Important systemic effects of infectious, autoimmune, neoplastic, and vascular diseases may be identified from ocular examination.
The purpose of sections I and II of this chapter is to provide an overview of the ocular history and basic complete eye examination as performed by an ophthalmologist. In section III, more specialized examination techniques will be presented.
The chief complaint is characterized according to its duration, frequency, intermittency, and rapidity of onset. The location, severity, and circumstances surrounding its onset are important, as is identifying any other ocular and nonocular symptoms that may require specific enquiry. Current eye medications and current and past ocular disorders are determined.
The past medical history must include enquiry about vascular disorder—such as diabetes and hypertension—and systemic medications, particularly corticosteroids because of their adverse ocular effects. Finally, any drug allergies should be recorded.
The family history is pertinent for ocular disorders, such as strabismus, amblyopia, glaucoma, or cataracts, and retinal problems, such as retinal detachment or macular degeneration. Medical diseases such as diabetes may be relevant as well.
A basic understanding of ocular symptomatology is necessary for performing a proper ophthalmologic examination. Ocular symptoms can be divided into three basic categories: abnormalities of vision, abnormalities of ocular appearance, and abnormalities of ocular sensation—pain and discomfort.
Symptoms and complaints should always be fully characterized. Was the onset gradual, rapid, or asymptomatic? (For example, was blurred vision in one eye not discovered until the opposite eye was inadvertently covered?) Was the duration brief, or has the symptom continued until the present visit? If the symptom was intermittent, what was the frequency? Is the location focal or diffuse, and is involvement unilateral or bilateral? Finally, does the patient characterize the degree as mild, moderate, or severe?
One should also determine what therapeutic measures have been tried and to what extent they have helped. Has the patient identified circumstances that trigger or worsen the symptom? Have similar instances occurred before, and are there any other associated symptoms?
The following is a brief overview of ocular complaints. Representative examples of some causes are given here and discussed more fully elsewhere in this book.
Loss of visual acuity ...