A slit-lamp examination is often performed by an optometrist during a routine eye exam. The procedure involves the use of an instrument called a slit-lamp, which provides a three-dimensional view of the eye. While the exam usually focuses on the structures in the front part of the eye, such as the cornea, iris and vitreous gel, it can also be used to examine the optic nerve and retina which are located at the back of the eye.

Reasons for a slit-lamp examination

An optometrist will perform a slit-lamp examination to check for any abnormalities of the eye caused by injury or infection and to diagnose conditions including cataracts, dry eye syndrome, keratoconus, diabetic retinopathy, Fuchs' dystrophy, uveitis, glaucoma, retinal detachment and macular degeneration. In patients who have already been diagnosed with a condition such as glaucoma or macular degeneration, slit-lamp exams may be performed to monitor the disorder.

How a slit-lamp examination is performed

During the procedure, the patient will be asked to sit facing the slit-lamp and keep their head still by resting their chin upon the chin rest attached to the instrument and placing their forehead against the head support. The optometrist will then shine a thin, bright light into the eye and look through the magnified lens to examine the front structures of the eye. In some cases, fluorescein eye drops may be administered. These drops are yellow in color and temporarily stain the tear film on the surface of the eye which can make it easier to detect corneal injuries and other abnormalities.

If structures in the back of the eye such as the retina or optic nerve need to be examined, the optometrist will typically administer eye drops to dilate the pupils. It will take about 15 to 20 minutes for the eyes to dilate, but once they're dilated the slit lamp procedure can be performed again, this time to examine the back of the eye. The eyes will remain sensitive to light for a few hours after being dilated, so sunglasses should be worn outside. Patients may also want to arrange for someone else to drive them home after the procedure.

If you suspect you have an eye condition or are due for a routine eye exam, contact your optometrist today to schedule an appointment.