The key to any examination is to be systematic and always perform each element!
1. Visual Acuity
- Describe vision as 20/X where X = the distance in feet a person with 20/20 vision would view the same optotype
- Example 1: A person with 20/50 vision sees at 20 feet what someone with 20/20 vision would see at 50 feet
- Example 2: A person with 20/10 vision sees at 20 feet what someone with 20/20 vision would see at 10 feet
- Vision poorer than 20/400 is typically described in terms of counting fingers at X feet, hand motions, or light perception with or without projection.
- CC: with correction
SC: without correction
- Observe pupil size and shape in the dark and light, using an indirect light source.
- Check the reactivity of each pupil separately with a muscle light or penlight, and then perform the swinging-flashlight test to evaluate for an afferent pupillary defect.
Swinging flashlight test: A normal pupillary response will have equal constriction in each eye. A relative afferent pupillary defect is present when the flashlight swings to the opposite eye and the one left in darkness slowly dilates instead of consensually constricting with the other pupil.
3. Extraocular Motility and Alignment
- Check corneal light reflexes to assess alignment. If not centered in pupils, perform cover testing.
- Have the patient follow an object in the six cardinal directions to assess versions (test ductions monocularly).
- Document muscle under action with a minus (–), over action with a plus (+) on a scale of 1 to 4, with 0 being normal motility.
4. Intraocular Pressure
Goldman applanation. Semicircles (viewed through the slit lamp ocular) showing the endpoint, in which the innermost aspects of the two semicircles are touching. Adjust the force applied to the cornea until the endpoint is reached.
Goldman applanation is the gold standard tonometry based on the Imbert-Fick principle where pressure = force/area. At a diameter of 3.06 mm, the force of corneal resistance to flattening is balanced by the capillary attraction of the tear film to the tonometer tip.
Be careful! If the mires rings are too wide, the pressure is overestimated; if they’re too thin, the pressure is underestimated.
5. Confrontation Visual Fields
Visual field assessment compares the examiner’s visual field (presumed normal) to the patient’s visual field. By presenting stimuli (fingers, light or objects) equidistant to both examiner and patient, to compare the response of the patient to your own.
6. External Examination
- Assess structures like lymph nodes and temporal arteries as indicated by the history.
- Assess lid position by measuring margin-to-reflex distance (MRD) in millimeters from the margin of the upper lid to the light reflex in the center of the cornea.
- Assess skin for any suspicious lesions that may need biopsy.
- Use an exophthalmometer to measure the degree of proptosis in millimeters.
- Test CNII-VIII if patient has sudden onset of diplopia or other neurologic symptoms.
- Check for step-off fractures of orbital rim and crepitus via palpation if history of trauma.
7. Slit-Lamp Examination
- Perform slit-lamp biomicroscopy to evaluate the optic nerve, macula and vessels.
- Lids/lashes/lacrimal system: Is the anatomy of the lid margin normal? Are there any lesions?
- Conjunctiva/sclera: Is it white and quiet? Is there injection? Are there any lesions?
- Cornea: Is it clear? Are all five layers normal in appearance?
- Anterior chamber: Is it deep? Is it quiet? Are there cells or flare?
- Iris: Is it round? Are there any lesions?
- Lens: Is it clear?
- Make note of the cup-to-disc ratio, asymmetry between the optic nerves and any focal thinning.
- Use an indirect ophthalmoscope to assess the retina periphery for tears/defects.
- Use the slit lamp to visualize the anterior vitreous and identify heme and pigmented or white cells.
- Draw any fundus pathology accurately and the size document in units such as disc diameters or disc areas.
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About the author: Edward H. Hu, MD, PhD, is a refractive cataract surgeon with Illinois Eye Center in Peoria, Ill. This is his fourth private practice environment, which is as close to a perfect practice as there is. After a bachelor’s degree in molecular biology from MIT, he got a PhD and MD from the New York School of Medicine. He completed residency at the University of Iowa Hospitals and Clinics.