Ophthalmoscopy is an examination of the back part of the eyeball (fundus), which includes the retina, optic disc, choroid, and blood vessels.

There are different types of ophthalmoscopy.

• Direct ophthalmoscopy
• Indirect ophthalmoscopy
• Slit-lamp 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 allows 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.) Some pressure may be applied to the eyeball using a small, blunt tool. You will be asked to look in various directions.

For information on slit-lamp ophthalmoscopy, see the article: Slit-lamp exam

Opthalmoscopy examination takes about 5 and 10 minutes.

Indirect ophthalmoscopy and slit-lamp ophthalmoscopy are performed after eye drops are placed to widen (dilate) the pupils. Direct ophthalmoscopy can be performed with or without dilation of the pupil.

The eye drops may make it hard to focus your eyes for several hours. You should arrange to have someone else to drive after the examination. Wearing sunglasses or tinted lenses will help make your dilated pupils more comfortable.

You should tell the health care provider if you:

• Are allergic to any medications
• Are taking any medications
• Have glaucoma or a family history of glaucoma

The bright light will be uncomfortable, but the test is not painful.

You may have a brief sensation of seeing images after the light shines in your eyes. The light is brighter with indirect ophthalmoscopy, so the sensation of seeing after-images may be greater.

Pressure put on the eyeball during indirect ophthalmoscopy by may be slightly uncomfortable, but should not be painful.

If eyedrops are used, they may produce a brief stinging sensation when placed in the eyes and an unusual taste in the mouth.

Ophthalmoscopy is done as part of a routine physical or complete eye examination.

It is used to detect and evaluate symptoms of retinal detachment or eye diseases such as glaucoma.

Ophthalmoscopy may also be done if you have signs or symptoms of high blood pressure, diabetes, or other diseases that affect the blood vessels.

The retina, blood vessels, and the optic disc should appear normal.

Abnormal results may be due to eye diseases such as a detached retina, optic nerve problems, macular degeneration, and changes caused by glaucoma. High blood pressure can also be detected.

Additional conditions under which the test may be performed:

• CMV retinitis
• Diabetes
• Hypertensive retinopathy
• Macular degeneration
• Melanoma of the eye

The test itself involves no risk. The dilating eye drops may rarely produce nausea, vomiting, dryness of the mouth, flushing, dizziness, or an attack of narrow-angle glaucoma. If the latter is suspected, drops generally are not used.

Ophthalmoscopy is considered to be 90-95% accurate and can detect the early stages and effects of many serious diseases.

Yanoff M, Duker JS, Augsburger JJ, et al. eds. Ophthalmology. 2nd ed. St. Louis, Mo: Mosby; 2004:1461-1462.

Ruamviboonsuk P, Wongcumchang N, Surawongsin P, Panyawatananukul E, Tiensuwan M. Screening for diabetic retinopathy in rural area using single-field, digital fundus images. J Med Assoc Thai. 2005 Feb;88(2):176-80.