What is the magnification of indirect ophthalmoscope?
The binocular indirect ophthalmoscope, or indirect ophthalmoscope, is an optical instrument worn on the examiner’s head, and sometimes attached to spectacles, that is used to inspect the fundus or back of the eye. It produces an stereoscopic image with between 2x and 5x magnification.
What is an indirect ophthalmoscope?
Listen to pronunciation. (IN-duh-REKT OF-thul-MOS-koh-pee) An exam of the inside of the back of the eye using a beam of light and a hand-held lens. Indirect ophthalmoscopy gives a wider view inside the eye than an exam using an ophthalmoscope does.
What is the power of the lens used in indirect ophthalmoscopy?
Indirect ophthalmoscopy is performed when the examiner views the image of a patient’s fundus through a condensing lens. Handheld lenses typically range in power from +14.00D to +40.00D, while condensing lenses included in a slit lamp may have a power as high as +120.00D.
Which is better 78D vs 90D?
In other words, the overall field-of-view comparison between a 90D and 78D funduscope is made such that: If the two lenses were of equal diameter, the 90D would create greater field; however, because the 78D is substantially larger than the 90D, it actually generates greater field of view; and, within the boundaries of …
What is 20D magnification?
The power of the condensing lens determines three things: viewing distance, magnification, and field of view. The magnification of a specific BIO lens is crudely determined by 60/the power of lens. Thus, a +20D lens would have a magnification of 60/20= 3X. 20D lens is the most commonly used lens for BIO in adults.
Why is it called indirect ophthalmoscope?
BIO is one of the ways used to view the retina, with a wide field of the retina and stereoscopic view. BIO also allows dynamic observation of the retina by moving the BIO device, lens, and applying scleral depression. The process is “indirect” because the fundus is viewed through a hand held condensing lens.
Which filters are used in indirect ophthalmoscope?
Cobalt blue filter is used along with fluorescein dye for angioscopy. A larger aperture light spot is used for a fully dilated pupil and intermediate and smaller apertures for a smaller or undilated pupil. Diffuse light filters and yellow filters make the illumination less bright and comfortable to the patient.
What is indindirect ophthalmoscopy?
Indirect ophthalmoscopy is done by ophthalmologists and optometrists to examine the retina as well as the optic nerve, vessels and macula lutea. The entire fundus can be seen in 3D up to the far retinal periphery using specifically our OMEGA instruments. HEINE Hand-held Indirect Ophthalmoscope BINOCULAR
How does a binocular indirect ophthalmoscope work?
Binocular indirect ophthalmoscope. The light source mounted above and between the examiner’s eyes illuminates the condenser, which images the source at the periphery of the patient’s pupil. The illumination does not overlap the observation beam. The condenser lens is handheld; it forms an inverted aerial image of the retina.
What is a direct ophthalmoscope?
A direct ophthalmoscope is a device that produces an unreversed or upright image of around 15 times magnification. The direct ophthalmoscope is a critical tool used to inspect the back portion of the interior eyeball, which is called the fundus. Examination is usually best carried out in a darkened room.
How do you adjust the scope on an indirect headset?
Adjust the indirect headset First, adjust the headband so that the scope is secure on your head. Then adjust the pupillary distance and height of the beam so you can see a full beam with each eye (Figure 3). Set the light aperture to the largest spot for a fully dilated patient.