Slit-lamp exam
Table of Contents:

Definition
The slit-lamp examination looks at structures that are at the front of the eye (the anterior segment): The eyelid, the sclerae (whites of the eyes), conjunctiva (membranes lining the eyelid and sclerae), iris (colored part of the eye), natural crystalline lens, and the cornea (thin transparent membrane that covers the iris and the lens). The slit-lamp is an instrument used with a high-intensity light source that can be focused to shine as a slit. It is used with the biomicroscope (an optical instrument that is like a microscope with two eyepieces).

How the test is performed
The biomicroscope and slit-lamp are swung in front of you and you rest your chin and forehead on a support to keep your head steady. Your eye is then examined through the biomicroscope. A fine strip of paper that is stained with an orange colored dye (fluorescein) is touched to the side of your eye. The dye stains the front part of the eye to help with the examination. The dye rinses out of the eye with tears. After this examination, drops are put in your eyes to dilate the pupils. The drops take about 15 to 20 minutes to work. The examination is then repeated, allowing the posterior segment of the eye to be examined.

How to prepare for the test
Adults:
No special preparation is necessary for this test.

Children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:



How the test will feel
There is some discomfort with the drops. Your eyes will be more sensitive to light for approximately 4 hours until the pupil is no longer dilated.

Risks
The dilating drops may cause nausea, vomiting, dryness of mouth, flushing, and dizziness. These symptoms rarely occur.

How the test is performed
The test looks for abnormalities of the eyelids, sclera, lens, conjunctiva, iris, and cornea.

Normal values
Structures in the eye are normal.

What abnormal results mean
Abnormal results may indicate general vision problems, corneal ulcers and infections or degeneration, an alteration in the shape of the cornea (farsightedness, nearsightedness), diseases of the retina, glaucoma (increase in eye pressure), cataracts, ocular inflammation (uveitis), and diseases that attack the nerves in the eyes.

Additional conditions under which the test may be performed:



Special Considerations
Not applicable.

[Definition] [How the test is performed] [How to prepare for the test] [How the test will feel] [Risks] [How the test is performed] [Normal values] [What abnormal results mean] [Special Considerations]