direct ophthalmoscope


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ophthalmoscope

 [of-thal´mo-skōp]
an instrument for examining the interior of the eye.
direct ophthalmoscope one that produces an upright, or unreversed, image of approximately 15 times magnification. The direct ophthalmoscope is used to inspect the fundus of the eye, which is the back portion of the interior eyeball. Examination is best carried out in a darkened room. The examiner looks for changes in the color or pigment of the fundus, changes in the caliber and shape of retinal blood vessels, and any abnormalities in the macula lutea, the portion of the retina that receives and analyzes light only from the very center of the visual field. Macular degeneration and opacities of the lens can be seen through direct ophthalmoscopy.
A, Inspection of the eye with a direct ophthalmoscope. B, Structures that are visualized. From Polaski and Tatro, 1996.
indirect ophthalmoscope one that produces an inverted, or reversed, direct image of two to five times magnification. An indirect ophthalmoscope provides a stronger light source, a specially designed objective lens, and opportunity for stereoscopic inspection of the interior of the eyeball. It is invaluable for diagnosis and treatment of retinal tears, holes, and detachments. The pupils must be fully dilated for satisfactory indirect ophthalmoscopy.
scanning laser ophthalmoscope (SLO) an instrument for retinal imaging in which light from a low-power laser beam that scans the retina is reflected back to a sensor; the light detected by the sensor is used to create a full-color composite digital image.

di·rect oph·thal·mo·scope

an instrument designed to visualize the interior of the eye, with the instrument relatively close to the subject's eye and the observer viewing an upright magnified image.

di·rect oph·thal·mo·scope

(dĭr-ekt' of-thal'mŏ-skōp)
An instrument designed to visualize the interior of the eye, with the instrument relatively close to the subject's eye and the observer viewing an upright magnified image.
References in periodicals archive ?
Observe the size of the pupils using a direct ophthalmoscope (set at +2.00DS with a large aperture of medium brightness at a distance of 50cm).
Tenders are invited for 207.01 Direct Ophthalmoscope (QTY.56 Nos.)
Gone are the days when practitioners were armed with nothing more that a direct ophthalmoscope, and a Bjerrum screen; those entering the profession today have an abundance of technology at their disposal, including video slit lamps, automated visual fields, fundus cameras, OCT, with the list lengthening year-on-year.
Tenders are invited for 820.01 Direct Ophthalmoscope (56 Nos.)
Thanks to their cooperative nature, we were able to get some excellent views of their retinas with a direct ophthalmoscope, something a lot of medical student struggle with in human patients.
Follow-up of 'stable' glaucoma in the community was performed by optometrists, the majority of whom (72%) were using a direct ophthalmoscope to monitor for progression--ophthalmologists stopped using direct ophthalmoscopes to examine the optic discs in favour of indirect biomicroscopy at least 20 years ago.

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