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Glaucoma > Lecture 7: The Optic Nerve in Glaucoma > Flashcards

Lecture 7: The Optic Nerve in Glaucoma Flashcards

1
Q

List the 9 generalized signs of optic nerve damage

A
  • Generalized enlargement c/d ratio
  • Increased dept of cupping
  • saucerization
  • Vertical elongation of c/d ratio
  • Cup-to-disc asymmetry
  • Loss of neuro-retinal rim
  • Peripapillary atrophy
  • Laminar dot sign
  • Pallor?
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2
Q

List 2 localized signs of optic nerve damage

A
  • Notching
  • Acquired pit of the ON
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3
Q

List 7 abnormalities of retinal vasculature

A
  • Hemes of the NFL
  • Focal narrowing
  • Vascular attenuation
  • Baring of circumlinear vessels
  • Overpass cupping
  • Nasalization of retina vessels
  • Optic disc shunt vessel
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4
Q

Larger discs have (larger/smaller) physiological cups

A

larger

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5
Q

The more ellipitical discs have (more/less) elliptical cups

A

more

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6
Q

optic disc is generally large in eyes with ____ and significantly smaller in eyes with marked ___.

A

high myopia; hyperopia (>+5)

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7
Q

Optic disc size may vary with race. list from smallest to largest.

A
  • Caucasians = smallest
  • Mexicans
  • Asian
  • African americans = largest
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8
Q

What is the normal optic disc size? What is the average size?

A
  • Normal size: 1.33-2.66mm in diameter
  • Average: 1.5
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9
Q

Approximately ___ neurons enter ONH

A

1.2 million

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10
Q

Why do we need to evaluate the RIM of the optic disc closely?

A

this is where nerve tissue is

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11
Q

___ and ___ have higher predictive power than the neuro-retinal rim as a whole. Why?

A
  • Inferotemporal and superotemporal
  • Preferential loss of rim in these regions in medium to advanced stages of GON (Lamina distortion theory)
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12
Q

______ of the cup is the most common type of change in progressive glaucoma. This disc change was found to preced VF loss by several years.

A

Generalized/concentric enlargement

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13
Q

Concentric enlargement most often seen in ___, ___ and __ pt who convert to glaucoma

A

NTG, early POAG and OHTN

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14
Q

T/F Depth is a specific finding for glaucoma. What is it affected by?

A
  • False, it is NOT SPECIFIC
  • Affected by
    • disc area
    • ethnicity, refractive error
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15
Q

In advanced stages of glaucoma, the ON may demonstrate “bean potting”. What is bean potting?

A
  • This relates to stress/strain & biomechanical principles applied to peripapillary sclera
  • Beanpotting: retinal blood vessels disappear as they follow the lateral excavation of the optic cup and reappear at the bottom of the cup
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16
Q

In normal eyes (Horizontal/Vertical) is larger than (Horizontal/Vertical)

A

horizontal is larger than vertical

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17
Q

Vertical elongation develops secondarily to the loss of … ?

A

neuro-retinal rim at superior and inferior poles

  • occurs less frequently than generalized enlargment of the cut BUT
    • more clinically significant; more easily diagnostic for glc
    • Can precede development of VF loss by several years
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18
Q

Vertical Elongation: c/d ratio more than __ greater vertically than horizontally (this would naturally violate ISNT)

A
19
Q

What is focal notching?

A

Area of localized damage

  • ​focal ischemia
  • correlate with VF defects (structure & function relationship)
  • May be preceded by drance heme
    • common in NTG
    • Typically at inferotemporal and superotemporal nerve
  • May lead to vertical elongation
20
Q

Focal loss of ganglion cell axons usually at the ___ & ___ poles of ONH

A

superior temporal & inferior temporal

21
Q

Notching happens most often at the ___ pole & is consistent with which theory?

A

inferior; lamina distortion theory

22
Q

Notching usually produces scotomas in ____ area

A

Bjerrum area

23
Q

What is zone alpha? Is this a normal or abnormal finding?

A
  • irregular pigmentation of RPE
  • Normal finding
24
Q

What is zone beta?

A
  • Atrophy of both RPE and choriocapillaris
  • crescet like region where you can view choroidal vessels
  • Progressive
  • Can respond to areas of rim loss
  • BUT NOT pathognomonic for glc
25
Q

List the area of progressive loss of rim in order

A
  • Inferotemporal –>
  • Superotemporal –>
  • Temporal –>
  • Inferonasal –>
  • Supernasal –>
26
Q

Asymmetry of c/d between the eyes: A difference of ___ or more is usually considered significant.

A C/D difference of >__ exists in only __% of normal eyes

A
  1. 2
  2. 2;1%
27
Q

If a person has an asymmetry of their ___ and overall ___ size, they wil lhave a physiological asymmetry (normal)

A

scleral canals and overall ONH size

28
Q

What is laminar dot sign?

It is visiable in only __% of myopic eyes

A
  • exposure of laminar structure due to loss of neural tissue
  • laminar dots become more obvious in eyes with significant glaucomatous nerve damage
  • remember they are not completely specific to glc
  • 34%
  • Represent holes in the lamina cribosa
29
Q

if lamina dots have a ___ or ___ shape, it may an indication of glaucoma

A

distorted or striate shape

30
Q

overall lamina dotes may indicate (mild/moderate/severe) glacuomatous damage and striate slit shapes may indicate more ____ glaucoma.

A

moderate; advanced

31
Q

T/F pallor in glaucoma is caued by loss of capillaries

A

FALSE, it is NOT

  • caused by increased visibility of supporting structures (e.g. sclera, CT, etc) due to enlargement of the cup
32
Q

Pallor is more typical of ____ optic neuropathy

A

non-glaucomatous

33
Q

Hemorrhage of NFL occur most frequently ___ and ___

  • can be seen in any location
  • more prevalent in ___ glaucoma
A

temporally and inferotemporally

NTG

34
Q

____ is highly specific for glaucoma

A

flame shaped heme - vasospastic activity of retinal vasculature could lead to disc heme

35
Q

Heme of NFL VF changes can occur when?

A

weeks to months later

  • sig risk that VF changes WILL happpen following a drance heme - ominous
36
Q

focal narrowing of vessels occur where?

A

where cupping is most significant

37
Q

Why does focal narrowing occur?

A

less demand for blood supply because fewer ganglion cells to supply

38
Q

Arterioles should be widest where?

A

inferotemporal and superotemporal

39
Q

___ is associated with overall loss of sensitivity VF testing

A

vascular attenuation

40
Q

Baring of circumlinear vessels occur in __% normal eyes and __% of eyes with glc

A

14%, 73%

41
Q

___ is considered a “soft sign”

A

nasalizatio of vessels

42
Q

____ vessels have a Z appearance due to sharpening of the border of the notch

A

bayonetic sign - rarely found in glaucomatous eyes

  • found in area of rim affected by focal notching
43
Q

The optic disc is best examined by ___

A

stereoophthalmoscopy

Glaucoma (11 decks)

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