Ophthalmoscopy Flashcards
direct ophthalmoscopy
- hand-held instrument
- provide a magnified MONOCULAR view inside the eye
- limited field of view
two types of indirect ophthalmoscopy
- monocular indirect
2. binocular indirect
monocular indirect
- better field of view than direct
- works well with smaller pupils
- less magnification than direct
binocular direct
- allows wide field of view and stereoscopic fundus evaluation
- best used with dilated pupil
Fundus Biomicroscopy
-refers to the use of lenses in conjunctino with biomicroscope(slit lamp) to view fundus
types of fundus biomicroscopy
- hruby lens(attached to microscope)
- fundus contact lenses( hold lens on cornea)
- non-contact condensing lens(lens held in front of eye)
Why dilation?
- enlargement of pupil with pharm drops
- allows better view of eye
- part of comprehensive eye exam
Why do people resist dilation?
- blurred vision
- light sensitivity
- long lasting
advantages to direct opthalmoscopy
- easier than BIO or fundus biomicroscopy
- good magnification
- ability to adjust focus from cornea to retina
disadvantages to direct ophthalmoscopy
- limited field of view
- no stereoscopic viewing(no depth perception)
- dim image limits resolution
direct ophthalmoscopy magnification
-like 15 times magnification
why would you examine macula last?
-very senstive and it will be bothered the rest of the ophthalmoscopy if you do not
does it matter what hand you use?
-yea, switch sides, switch hands
what order should you look at things?
- optic nerve
- blood vessels
- macula
C/D ratio
-ratio of optic nerve cup diameter to total optic nerve diameter
What is the cup is oval or not centered??
- measure horizontal and vertical
- record horizontal/ vertical
what should you be looking at when analyzing the optic nerve
- C/D ratio
- rim color
- margins
- spontaneous venous pulsation
what should you be looking at when analyzing the blood vessels?
- arteriovenous ratio
- AV crossing changes
vein/ artery comparisson
- vein is larger and darker than artery
- artery usually goes over vein
hardened arteriole
-artery is thickened and heavier so it causes a nick on vein
fovea
- red dot inside macula
- if white dot inside of fovea, healthy and younger patients
macula obervarions
homogenous color?
- foveal reflex?
- abnormal?
is direct ophthalmoscopy sufficient as a stand alone procedure for fundus exam?
-nope
what is more commonly used for a comprehensive fundus evaluation?
-BIO and biomicroscopy(slit lamp)
So why would we learn direct?
- easy
- can supplement other things
- like if someone comes in with a red eye, just check real fast
summary advantages and disadvantages
A -high magnification -easy D -limited field of view -lack of stereopsis
