Ophthalmoscopy is an examination of the back part of the eye (fundus), which includes the retina, optic disc, choroid, and blood vessels.
How the test is performed
There are different types of ophthalmoscopy.
Direct ophthalmoscopy: You will be seated in a darkened room. The health care provider performs this common exam by shining a beam of light through the pupil using an instrument called an ophthalmoscope. An ophthalmoscope is about the size of a flashlight. It has a light and several different tiny lenses that allow the examiner to view the back of the eyeball.
Indirect ophthalmoscopy: You will either lie or sit in a semi-reclined position. The health care provider holds your eye open while shining a very bright light into the eye using an instrument worn on the head. (The instrument looks like a miner's light.) The health care provider views the back of the eye through a hand-held lens held close to your eye. Some pressure may be applied to the eyeball using a small, blunt probe. You will be asked to look in various directions.
Slit-lamp ophthalmoscopy: 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 use the microscope part of the slit lamp and a tiny lens placed close to the front of the eye. The health care provider can see about the same with this technique as with indirect ophthalmoscopy, but with higher magnification.
The opthalmoscopy examination usually takes about 5 to 10 minutes.
How to prepare for the test
Indirect ophthalmoscopy and slit-lamp ophthalmoscopy are performed after eyedrops are placed to widen (dilate) the pupils. Direct ophthalmoscopy and slit-lamp ophthalmoscopy can be performed with or without the pupil dilated.
The eyedrops may make it hard for you to focus your eyes for several hours. You should arrange to have someone drive you after the examination. Wearing sunglasses or tinted lenses will help make your dilated pupils more comfortable.
The test itself involves no risk. The dilating eye drops may rarely cause:
An attack of narrow-angle glaucoma
Dryness of the mouth
If glaucoma is suspected, drops usually are not used.
Ophthalmoscopy is considered to be 90-95% accurate. It can detect the early stages and effects of many serious diseases.
American Academy of Ophthalmology Preferred Practice Patterns Committee. Preferred Practice Pattern Guidelines. Comprehensive Adult Medical Eye Evaluation. Available at http://one.aao.org/CE/PracticeGuidelines/PPP_Content.aspx?cid=64e9df91-dd10-4317-8142-6a87eee7f517. Accessed February 26, 2013.
Colenbrander A. Principles of ophthalmoscopy. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 2013 ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2012:vol 1, chap 63.
Volk D. Aspheric lenses. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 2013 ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2012:vol 1, chap 50.
Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.