ophthalmoscope
Meaning of ophthalmoscope: A handheld light and lens that turns the pupil into a window onto living blood vessels and nerve tissue.
Definition of ophthalmoscope
An ophthalmoscope is a handheld instrument that shines light through the pupil so an examiner can see the back of the eye. It brings the retina, its blood vessels and the head of the optic nerve into view. Because those vessels are visible directly, the examination reports on circulation and pressure conditions that affect the rest of the body as well.
How ophthalmoscope is built
- ocul/o, ophthalm/o Combining form · Latin and Greek eye
- -scope Suffix · Greek instrument for viewing
A medical term is read from its ending backwards: the suffix first, then the prefix, then the root. See all 223 word parts.
What can be seen through it?
| Structure | What it reveals |
|---|---|
| Optic disc | Where the optic nerve leaves the eye; swelling or cupping shows here |
| Retinal arteries and veins | Narrowing, nipping at crossings, blockages |
| Macula | The small central area responsible for fine detail |
| Retinal background | Bleeding, deposits, new fragile vessels, detachment |
Why examine the back of the eye at all?
The retina is the only place in the body where small blood vessels can be seen directly, without cutting or imaging. What happens to them there tends to mirror what is happening to small vessels elsewhere. Long-standing diabetes produces bleeding points, deposits and eventually fragile new vessels. Sustained high blood pressure narrows the arteries and presses on veins where the two cross. Raised pressure inside the skull pushes fluid forward along the optic nerve and swells the disc, a sign called papilledema that can be the first clue to a mass or blocked drainage in the brain.
Direct or indirect?
Two instruments share the name and give different views. The direct ophthalmoscope is the small handheld device carried in a pocket. It is held close to the eye, gives a highly magnified but narrow view, and shows the image the right way up. The indirect version is worn on the head, uses a lens held in front of the eye, and gives a wide, three-dimensional view of the periphery, though the image appears upside down and back to front. Widening the pupil with drops makes either examination far easier, and the periphery is difficult to inspect properly without it.
What are its limits?
The view depends on clear media. A dense cataract, blood inside the eye or a small pupil can obscure everything behind them. Photography and scanning instruments now record the same view in detail and allow images to be compared over time, but the handheld instrument remains the fastest way to look.
Also known as
Used in a sentence
Examination with an ophthalmoscope showed a swollen optic disc in both eyes.
Good to know
The retina offers the only direct view of small blood vessels in a living body, so findings there carry information about diabetes and blood pressure elsewhere.
Word origin
Where “ophthalmoscope” comes from
From the Greek ophthalmos, meaning eye, and skopein, meaning to look at.