Flashcards in Lecture 3 Deck (35)
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1
what 5 things do you examine for for the optic nerve?
disc size, margins, contour of rim tissue, C/D ratio and rim tissue and NFL
2
what is a distinct margin?
easy to see the edges of the disc 360 - not uncommon for nasal to be indistinct and still be normal
3
what is an indistinct margin?
unable to see the edges of the disc for the majority of the ONH diameter
4
what is a normal and abnormal variation of an indistinct nerve?
normal = heaped up appearances or small congenital anomalous nerves
abnormal = papilledema
5
what is a malinserted disc?
congenital - disc is tilted along the vertical axis (appears to tilt upward nasally and down temporal, often has a scleral crescent)
6
what is a tilted disc?
congenital - the vertical axis is tilted, often downward nasally (often associated with tilted disc syndrome)
7
what 3 things can cause papilledema?
increased ICP due to brain lesion, idiopathic intracranial hypertension, and hypertensive crisis (bilateral)
8
what are 3 pseudopapilledemas (AKA congenital disc anomalies)?
optic nerve head drusen, congenitally full disc, and malinserted disc
9
when looking at a the ONH - how do you know if there is papilledema vs. pseudopapilledema?
if swollen (papilledema) - the view of the vessels will be obscured (like looking through a cloud)
10
what 5 signs point to papilledema?
indistinct margins, - SVP, + obscuration of vessels and hyperemic rim color
11
what information does the contour or "type" of ON rim provide?
contour provides information of the neuroretinal rim tissue, also helps to look for notching for glaucoma and vessel deflection
12
what are the 4 types of ONH contour?
flat, cylinder, slope/bowel, and hooked
13
what is the C/D and physiological cupping typically for a type 1 nerve (flat)?
C/D = 0-0.2
cupping = less than or equal to 1 diopter in depth
14
what is the C/D and physiological cupping typically for a type 2 nerve (cylindrical)?
sharp temporal rim
C/D = 0.15-0.65
cupping = 1=5 diopters in depth
15
what is the C/D and physiological cupping typically for a type 3 nerve (slope/bowel)?
C/D = 0.15-0.65+
cupping = 1-3 diopters in depth
16
what is the C/D and physiological cupping typically for a type 4 nerve (hooked)?
C/D = 0.2-0.7+
cupping = 1-5 diopters in depth
17
what is the ISN'T rule?
the inferior border should be the thickest > Superior > Nasal > Temporal (thinnest)
18
how is the ISN'T rule helpful in glaucoma?
the vertical C/D increases faster than horizontal - doesn't follow the ISN'T rule
19
when judging the C/D, where do you measure the disc diameter from?
the first point of deflection of the disc vessels from the neural rim bending towards the optic cup - not color change
20
what are the average C/D for Caucasians, African Americans and Asian/Latinos?
Caucasians = 0.4
African Americans = 0.6
Asian/Latinos = 0.5
21
what is a normal amount of asymmetry between the two eyes C/D?
30% = 0.1 difference and 4% have a 0.2 difference
22
what does a normal healthy, young NFL look like?
with red-free filter it should have a shimmering reflection
23
what 4 things to you look for during retinal vessel evaluation?
A/V ratio, ALR, delfections or crossing defects, and area around the vessels (white, red, dark stuff)
24
what is a normal A/V ratio and where do you look to compare?
normal = 2/3 or 3/4
estimation should be made after the first bifurcation and before the third
25
what should you think if the veins are too wide? or arteries are too narrow?
veins too wide = think diabetes
arteries too narrow = HTN
26
what is ALR?
arteriolar light reflex - ratio of the width of light being reflected off the surface of the artery to the overall width of the artery
27
what is a normal ALR?
1/3 or 1/4
28
what happens to the ALR with arteriosclerosis and HTN?
the ALR thickens - as the walls of the artery thicken, less light is allowed to pass through and more is reflected back
29
what 4 things can happen to the vessel crossings with arteriolar sclerosis and HTN?
compression, deflection of the underlying vein, humping, and tapering (nicking)
30
what are tortuous vessels?
vessels appear to be crooked or winding (if both vein and artery, usually congenital)
31
what are the 5 fundus types?
albino, blonde, brunette, dark, and tigroid
32
what is difference about an albino fundus?
there is no macular pigment (no RPE layer)
33
what 5 things do you evaluate in the macula?
even pigmentation, foveal light reflex, hemorrhages, drusen, and pigmented lesions
34
what is the foveal light reflex (FLR)?
a reflex actually located in the vitreous as a result of the shape of the retina and the "depression" of the fovea
35
