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Slit-lamp exam
Biomicroscopy
The slit-lamp examination looks at structures that are at the front of the eye.
How the Test is Performed
The slit-lamp is a low-power microscope combined with a high-intensity light source that can be focused as a thin beam.
You will sit in a chair with the instrument placed in front of you. You will be asked to rest your chin and forehead on a support to keep your head steady.
The health care provider will examine your eyes, especially the eyelids, cornea, conjunctiva, sclera, and iris. Often a yellow dye (fluorescein) is used to help examine the cornea and tear layer. The dye is either added as an eyedrop. Or the provider may touch a fine strip of paper stained with the dye to the white of your eye. The dye rinses out of the eye with tears as you blink.
Next, drops may be placed in your eyes to widen (dilate) your pupils. The drops take about 15 to 20 minutes to work. The slit-lamp examination is then repeated using another small lens held close to the eye, so the back of the eye can be examined.
How to Prepare for the Test
No special preparation is needed for this test.
How the Test will Feel
Your eyes will be sensitive to light for a few hours after the exam if dilating drops are used.
Why the Test is Performed
This test is used to examine the:
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Conjunctiva
Conjunctiva
The conjunctiva is a thin membrane that covers the inner surface of the eyelid and the white part of the eyeball (the sclera). Inflammation of the co...
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- Eyelids
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Iris
Iris
The iris is the colored part of the eye. It is located between the cornea and lens. The round, central opening of the iris is called the pupil. Ve...
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Sclera
Sclera
The sclera is the white outer coating of the eye. It is tough, fibrous tissue that extends from the cornea (the clear front section of the eye) to t...
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Normal Results
Structures in the eye are found to be normal.
What Abnormal Results Mean
The slit lamp exam may detect many diseases of the eye, including:
- Clouding of the lens of the eye ( cataract )
-
Injury to the clear tissue (cornea)
that covers the front of the eye
Injury to the clear tissue (cornea)
Corneal injury is a wound to the part of the eye known as the cornea. The cornea is the crystal clear (transparent) tissue that covers the front of ...
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Dry eye syndrome
Dry eye syndrome
You need tears to moisten the eyes and to wash away particles that have gotten in. A healthy tear film on the eye is necessary for good vision. Dry...
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Loss of sharp vision due to
macular degeneration
Macular degeneration
Macular degeneration is an eye disorder that slowly destroys sharp, central vision. This makes it difficult to see fine details and read. The diseas...
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Separation of the light-sensitive membrane (retina) in the back of the eye from its supporting layers (
retinal detachment
)
Retinal detachment
Retinal detachment is a separation of the light-sensitive membrane (retina) in the back of the eye from its supporting layers.
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Blockage in a small artery that carries blood to the retina (
retinal vessel occlusion
)
Retinal vessel occlusion
Retinal artery occlusion is a blockage in one of the small arteries that carry blood to the retina. The retina is a layer of tissue in the back of t...
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Damage of the retina (
retinitis pigmentosa
)
Retinitis pigmentosa
Retinitis pigmentosa is an eye disease in which there is damage to the retina. The retina is the layer of tissue at the back of the inner eye. This...
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Swelling and irritation of the uvea (
uveitis
), the middle layer of the eye
Uveitis
Uveitis is swelling and irritation of the uvea. The uvea is the middle layer of the eye. The uvea provides most of the blood supply to the retina....
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This list does not include all possible diseases of the eye.
Risks
The dilating drops may cause increased pressure in the eye with nausea and pain. This is very rare, but you should return to your doctor's office right away if you experience either of these symptoms.
References
American Academy of Ophthalmology Preferred Practice Patterns Committee. Preferred Practice Pattern Guidelines. Comprehensive Adult Medical Eye Evaluation -- 2010. Available at one.aao.org/preferred-practice-pattern/comprehensive-adult-medical-eye-evaluation--octobe. Accessed February 22, 2015.
Colenbrander A. Principles of ophthalmoscopy. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology . 2013 ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:vol 1, chap 63.
Fellman RL, Grover DS, Spaeth GL. Gonioscopy. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology . 2013 ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:vol 3, chap 44.
Miller D, Thall EH, Atebara NH. Ophthalmic instrumentation. In: Yanoff M, Duker JS, eds. Ophthalmology . 4th ed. Philadelphia, PA: Elsevier Mosby; 2014:chap 2.8.
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Eye - illustration
The eye is the organ of sight, a nearly spherical hollow globe filled with fluids (humors). The outer layer or tunic (sclera, or white, and cornea) is fibrous and protective. The middle tunic layer (choroid, ciliary body and the iris) is vascular. The innermost layer (the retina) is nervous or sensory. The fluids in the eye are divided by the lens into the vitreous humor (behind the lens) and the aqueous humor (in front of the lens). The lens itself is flexible and suspended by ligaments which allow it to change shape to focus light on the retina, which is composed of sensory neurons.
Eye
illustration
-
Slit-lamp exam - illustration
A slit-lamp, which is a specialized magnifying microscope, is used to examine the structures of the eye (including the cornea, iris, vitreous, and retina). The slit-lamp is used to examine, treat (with a laser), and photograph (with a camera) the eye.
Slit-lamp exam
illustration
-
Eye lens anatomy - illustration
The lens of the eye is normally clear. If the lens becomes cloudy or is opacified it is called a cataract.
Eye lens anatomy
illustration
-
Eye - illustration
The eye is the organ of sight, a nearly spherical hollow globe filled with fluids (humors). The outer layer or tunic (sclera, or white, and cornea) is fibrous and protective. The middle tunic layer (choroid, ciliary body and the iris) is vascular. The innermost layer (the retina) is nervous or sensory. The fluids in the eye are divided by the lens into the vitreous humor (behind the lens) and the aqueous humor (in front of the lens). The lens itself is flexible and suspended by ligaments which allow it to change shape to focus light on the retina, which is composed of sensory neurons.
Eye
illustration
-
Slit-lamp exam - illustration
A slit-lamp, which is a specialized magnifying microscope, is used to examine the structures of the eye (including the cornea, iris, vitreous, and retina). The slit-lamp is used to examine, treat (with a laser), and photograph (with a camera) the eye.
Slit-lamp exam
illustration
-
Eye lens anatomy - illustration
The lens of the eye is normally clear. If the lens becomes cloudy or is opacified it is called a cataract.
Eye lens anatomy
illustration
Review Date: 2/23/2015
Reviewed By: Franklin W. Lusby, MD, ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
