Ophthalmoscopy Flashcards
What is Direct Ophthalmoscopy?
- hand-held instrument providing magnified monocular view inside eye
- limited field of view
What are the two types of Indirect Ophthalmoscopy?
monocular indirect (MIO) binocular indirect (BIO)
What is monocular indirect (MIO)?
MIO offers a better field of view than direct because it works well with smaller pupils. MIO offers less magnification than direct.
What is binocular indirect (BIO)?
BIO allows a wide field of view and stereoscopic fundus evaluation. It is best used with dilated pupil.
MIO offers a better field of view than direct because it works well with _____. MIO offers ____ magnification than direct.
smaller pupils
less
BIO allows a ____ field of view and a _____ fundus evaluation. It is best used with a ______.
wide
stereoscopic
dilated pupil
What is Fundus Biomicroscopy?
Refers to the use of lenses in conjunction with a biomicroscope (slitlamp) to view the fundus.
What are the types of Fundus Biomicroscopy?
- Hruby lens
- fundus contact lenses
- non-contact condensing lenses
Dilation: what, why, and when?
- Pharmacologic enlargement of pupil via eye drops
- Allows much better view into the eye
- Integral part of any truly “comprehensive” eye care
Some patients/practices resistant: Many patients simply don’t understand the advantages.
Perceived disadvantages:
- blurred vision (unable to drive)
- light sensitivity (uncomfortable)
- long-duration
What are advantages of direct ophthalmoscopy?
- Easier to do than BIO or fundus biomicroscopy
- Provides good magnification
- Ability to adjust focus (cornea to retina)
What are disadvantages of direct ophthalmoscopy?
- Limited field of view
- Does not allow stereoscopic viewing (no depth perception)
- Relatively dimmer image limits resolution
What are the step to perform Direct Ophthalmoscopy?
Clinical Procedure
• Patient seated just below your eye level
• Room lights dimmed
• Patient views large distant target
• Stand to side of eye to be examined
• Ophthalmoscope held in same had as eye to be examined
• Using spot beam, look through scope from about 40 cm in front of patient (just temporal to their line of sight) and focus on iris
• Observe retinal reflex, looking for media opacities
• Slowly move closer to patient’s eye (to just in front of eyelashes), while adjusting focus until fundus structures come into clear view.
What do you look for while do Direct Ophthalmoscopy?
Clinical Procedure
• Locate the optic nerve head
• Examine the disc noting it’s appearance
• Examine the area adjacent to the disc
• Examine the area further out into all quadrants
• Lastly, move into line of sight to examine macula
• Switch sides (hands) and repeat on other eye
What are the key landmarks you look for in direct ophthalmoscopy?
Optic cup Optic disc Fovea Macula Artery Vein
What do you record for direct ophthalmoscopy for the optic nerve?
Optic nerve: • cup-to-disc (C/D) ratio • rim color • margins • spontaneous venous pulsation (SVP)?
Note: Spontaneous venous pulsations are a common occurrence in normal eyes (75 %). Retinal veins pulsate because there is a momentary imbalance between the pressure on the outside of the wall that overcomes momentarily the rigidity of the wall and the internal pressure of the vein.
What do you record for direct ophthalmoscopy for blood vessels?
Blood vessels:
• arteriovenous (AV) ratio and any AV crossing changes
What do you record for direct ophthalmoscopy for the macula?
Macula:
• Does it have homogenous color?, a foveal reflex?
What is the optic nerve cup?
It is where the optic nerve dips down.
What is the optic nerve disc?
It is the optic nerve margin.
What is the cup/disc ratio?
It’s the ratio of the optic nerve cup diameter to the total optic nerve diameter.
Think of it like this:
The impressed area divided by the entire disc
yellow/red
Recording cup-to-disc (C/D) ratio:
Cup can be oval ______ and may be ______.
(different horizontal and vertical dimensions)
decentered
Recording cup-to-disc (C/D) ratio:
Recorded as a decimal for both horizontal and vertical dimensions, with _______first:
horizontal
H/V
C/D ratio: 0.3/0.2
Summary
• Direct ophthalmoscopy is ______ as a single or stand-alone procedure for ocular fundus examination.
- Replaced in large measure by ________ and ___________ for comprehensive fundus evaluation.
- Still important because easiest method of fundus evaluation to learn, and may be used to supplement other procedures.
- Ease of use and _____magnification are main advantages, while limited field of view and lack of stereopsis are disadvantages.
insufficient
stereoscopic ophthalmoscopy (BIO) and biomicroscopy (slit-lamp)
high magnification and limited field of view
