Alternate Names: Funduscopy
How Performed:
Direct Ophthalmoscopy: You will be seated in a darkened room. The examiner performs this common examination by projecting a beam of light from an ophthalmoscope, an instrument about the size of a flashlight, through the pupil to view the back of the eyeball.
The magnification obtained by using the direct ophthalmoscope is due to the fact that the eye itself serves as a simple magnifier. The rotating lenses incorporated in the instrument are used to compensate for the refractive error of the examiner and/or the patient being examined.
Indirect Ophthalmoscopy: You will either lie or sit in a semi-reclining position. The examiner performs this examination by holding the eye open. The examiner wears an instrument on the head resembling a miner’s light. While holding the eye open and using a hand-held instrument, the examiner shines a very bright light into the eye. Some pressure may be applied to the eyeball using a small, blunt instrument, and you will be asked to look in various directions. This examination takes between 5 and 10 minutes.
How To Prepare: Indirect ophthalmoscopy is performed after eye drops are placed to dilate the pupils. Direct ophthalmoscopy can be performed with or without dilation of the pupil. The dilating drops may impair focusing of the eyes for several hours. Therefore, arrangements should be made for transportation after the examination. Wearing sunglasses or tinted lenses will make the patient with dilated pupils more comfortable.
You should tell the examiner if you:
- are allergic to any medications
- any medications are being taken
- have glaucoma or a family history of glaucoma
Infants and 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 It Feels: Direct ophthalmoscopy: As the scope is focused, a clicking sound will be heard. The bright light shone into the eyeball may cause brief after-images to be seen.
Indirect ophthalmoscopy: The light is brighter with indirect ophthalmoscopy, so the sensation of seeing after-images may be greater. Pressure put on the eyeball by the blunt instrument may be slightly uncomfortable, but should not be painful. The fundus can usually be seen through cataracts.
If eyedrops are used, they may produce a brief stinging sensation when put in the eyes and a medicinal taste in the mouth caused by the medication draining from the tear ducts into the throat.
Risks: The test itself involves no risk. The dilating eye drops could produce a rare instance of 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.)
Why Performed: Ophthalmoscopy is performed as part of a routine physical or complete eye examination to detect and evaluate symptoms of eye disease, such as glaucoma, or if diabetes, atherosclerosis, or hypertension is suspected.
Normal Values: The retina, blood vessels and the optic disc should appear normal to the examiner.
Abnormal Results: Eye diseases such as cataracts, cloudy vitreous, detached retina, optic nerve degeneration or swelling, and changes caused by glaucoma can be detected. Diabetes, hypertension (high blood pressure), and some systemic disease can also be detected.
Additional conditions under which the test may be performed:
Cost:
Special Considerations: Since it can detect the initial stages and early physiological effects of heart and blood vessel disease (particularly high blood pressure); brain disease; diabetes; and specific eye diseases, ophthalmoscopy (considered to be 90 to 95 percent accurate) is one of the most valuable tests.