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Flashcards in Glaucoma COPY Deck (149):
1

Pilocarpine : Mechanism of Action

Parasympathomimetic - Pilocarpine directly stimulates cholinergic receptors, acting on a subtype of muscarinic receptor (M3) found on the iris sphincter muscle, causing the muscle to contract and produce miosis. timulates the sphincter pupillae in the iris and the ciliary muscle, resulting in displacement of the scleral spur, opening of the trabecular meshwork and/or Schlemm’s canal, and enhancement of conventional aqueous outflow.

2

Beta-Blockers: MOA

Beta-blockers decrease aqueous humor production by the ciliary body and hence reduce IOP.

3

Carbonic Anhydrase Inhibitors

Carbonic anhydrase is an enzyme that catalyzes the reaction of H2O and CO2 in equilibrium with H+ and HCO3−. The net effect of the enzyme on aqueous production is to generate bicarbonate ions, which are transported actively across the ciliary epithelial membrane into the posterior chamber (sodium is the primary cation); an osmotic gradient is established. Water passively follows because of the presence of the gradient, which results in aqueous production. Inhibition of this enzyme results in lower IOP because aqueous production is decreased approx 50% or more;aqueous outflow and episcleral venous pressure are affected little or not at all.

4

Alpha-Adrenergic Agonists

Apraclonidine decreases aqueous production but is also associated with an increase in outflow facility and a decrease in episcleral venous pressure. Brimonidine is 23 times more alpha-2 selective than apraclonidine and 12 times more selective than clonidine. Its mechanism of action includes a reduction in aqueous formation as well as an increase in uveoscleral outflow

5

Relate Ciliary Body Anatomy to demonstrate the difference between Angle Recession, cyclodialysis and irido-dialysis

Angle recession is a separation between the longitudnal and radial muscles of the ciliary body. (you see a wide CB band but otherwise N structures) Cyclodialysis is when the longitudnal muscles separate from the scleral spur and ca cause hypotony and haemorrhage. Irido dialysis is separation of the iris root and the ciliary body.

6

OHTS found 5 significant risk factors that increased the risk of POAG

- age
- higher iop
- CDR
- greater pattern standard deviation
- reduced CCT

7

What were the pressure lowering goals of OHTS and CNTGS

OHTS: 20% from baseline

CNTGS: 30% from baseline

8

What are the risk factors for steroid responders (5)

- known POAG
- family hx
- age
- DM
- myopia

9

DDx of arcuate defects

Glaucoma
ONH drusen
NAION, AAION
Myelinated NFL
Hemiretinal vein occlusions
BRAO
Optic nerve colobomas, pit
Laser scars to one area of retina

10

DDx of enlarged blind spot

ONH drusen
Papilledema
Diabetic papillitis
Hypertensive papillitis
Optic neuritis
MEWDS/IEBSS
Megalopapilla
High myopia (PPA)

11

Glaucomatous nerve features

High CDR
Assymetric CDR
Notch
Loss of NFL
Optic disc hg
Bayonetting of vessels
Nasalisation of vessels
Vertical elongation of the cup
Laminar dots (?)

12

Systemic associations with drusen

Autosomal dominant
PXE
Sickle cell

13

DDx of glaucomatous nerve

Physiologic cupping
Tilted discs

Anything that causes nerve damage...
Glaucoma (open or closed)
Optic neuropathies
compression
toxic/metabolic
vascular insults

14

Disc hg ddx

Glaucoma (esp NTG)
Hemorrhagic PVD
Papilledema
NAION
AAION
Diabetes
HTN
Valsalva

15

Thickest rim

I>S>N>T

16

Most suspectible to glaucoma (parts of the rim)

I>S>T>N

17

Angle most open

Inferior

18

Angle most pigmented

Inferior

19

Deep AC in who

Myopes
Young
Male
(basically everyone who gets PDS)

20

Shallow AC in who

Old
female
hyperopes
Eskimo/Asians

21

Steroid responder risks (5)

POAG
Family history
Age
Myopia
DM

22

CDN guidelines for suspect, early, mod, and adv glaucoma (dx and management)

Class; CDR; VF; Tmax you want; lower by


Suspect; --- ; --- ; 24; 20%
Mild; 10deg from fixation; 20; 25%
Moderate; 10 deg from fixation; 17; 30%
Severe: >0.9, within 10 deg of fixation; 14; 30%

23

Dose of MMC for trab

0.01% for 2 min (in real life this varies but this is a reasonable exam answer)

24

Two types of VF testing

Static (Humphrey or Goldmann)
Kinetic (Goldmann)

25

DDx of hyphema in adult

Trauma
Bleeding diathesis
Leukemia
Ocular surgery
Fuch's
Other NVI/NVA
UGH

26

PXF cataract risks

Poor dilation
Stiff pupil
Zonular weakness
Increased risk of phacodynesis and vitreous loss
Capsular fragility
Lower endothelial cell count
Unstable IOP post-op (spikes)
Post-op inflammation

27

Findings in PXF

Poor dilation
Ring of pigment on anterior lens capsule
PXF material on pupil margin
Pupil margin TID
Pigmented angle
Sampolessi line

28

Membrane over angle

ICE
Epithelial ingrowth
PAS (uveitis, bad ALT, chronic ACG)
NVI

29

ICE clinical variants

Chandler - mostly cornea
Iris nevus - membrane on iris tents up normal stroma to look like nevi (not actually nevi)
Essential iris atrophy (correctopia/polycoria)

30

3 lytic glaucomas

Lytic = macrophages clog up TM with junk

Phacolytic - lens particles
Hemolytic - RBC from hyphema
Melanomalytic - pigmented melanocytes (or something) from melanoma cells floating around

31

Secondary glaucomas after IOL implantation

UGH
Pupil block angle closure
Secondary pigmentary glaucoma

32

Pigmented TM in who

Pigmented people
Older people
PXF
PDS
Melanomas

33

IOP formula

IOP = F/C + EVP

34

Types of tonometry

Indentation - Schiotz

Applanation - tonopen, Goldmann, Perkins, pneumotonometer (don't let this last one throw you - unless they say AIR PUFF, it's still a contact tonometer)

Non-contact - air puff

35

Glaucoma with pigment

PXF
PDS
Pigmented people with open angles
Pigment on endothelium from old inflammation, cataract surgery, trauma, hyphema
ICE
Melanoma

36

Intermittent ACG findings

Hx of intermittent ACG
+/-Normal IOP
PAS
Glaucomflecken
Signs of glaucmatous damage to ON

37

Risk of ACG in the fellow eye after AACG

75%. So always do prophylactic LPI

38

Segmental iris atrophy

Cataract surgery
Trauma
HSV, EBV, CMV, VZV
ICE syndrome
Axenfeld reiger
PPMD

39

Iridodenesis

Separation of iris from CB
Usually result of trauma or surgery
Rx with coloured CL or surgically re-insert

40

Causes of ectropion uveae

ICE
Axenfeld reiger
Uveitis
PPMD
NF-1
Epithelial downgrowth
NVG
uveitis

41

How do you tell epithelial ingrowth vs fibrous downgrowth

Epithelial ingrowth turns white with YAG

42

Lens induced glaucomas

Phacomorphic - angle closure with pupil block
Phacolytic - lens particles leak through intact capsule. Minimal inflammation, but macrophages ingest the particles and obstruct. NO KP.
Phacoanaphylactic - broken capsule. Maybe after surgery. Some books call this the same as lens particle glaucoma. LOTS OF INFLAMMATION with KP's.
Lens particle - basically the same thing. Maybe it's more after cataract surgery with some lens left behind.

UGH - from IOL
Dislocated lens (if dislocates anteriorly, causes ACG)
Same with microspherophakia causing ACG

43

Cyclodialysis def'n and treatment

Separation of CB from SS
Result of either trauma or surgery
Gonio to confirm
Rx with cycloplegics, most will close on their own in 6/52
Cause hypotony in the meantime, +/- spike when its closing

44

Risks for OHTN progression

Age
High IOP
High CDR
High pattern standard deviation
Low CCT

45

CCT definition in OHTS

588 = thick

46

RF for OAG

Age
High IOP
Family history
Race
Other: HTN, DM, Myope, migraines?

47

RF for AACG

Female
Age
Previous ACG
Race - inuit or asian
Hyperopic
Nanophthalmos
Family history

48

RF for NTG

Female
Disc hg
migraine
vasospasm/raynauds
smoking

49

DDx of NTG

IOP is high, but you're not measuring it:
- uncalibrated equipment
- low CCT
- corneal edema

IOP is high sometimes but you're missing it:
- diurnal fluctuations
- intermittent ACG
- Posner Schlossman episodes

IOP was high before but its ok now:
- burned out OAG (PDS, PXF)
- old AACG

It's not glaucoma at all:
- ONH drusen
- old optic neuritis, NAION, AION, etc
- compressive lesion (do a CT - nerve to chiasm)
- infiltrative lesion of the nerve (sarcoid, TB, lyme, etc)

Only if you've ruled all that out can you call it NTG.

50

Acute IOP rise ddx

After laser (LPI, SLT, etc)
After surgery (retianed visco, retained lens particles)
Inflammatory (HSV, CMV, Posner Schlossman, Fuch's)
Steroid responder
After hyphema
AACG

51

Characteristics of plateau iris and treatment

Deep central AC, shallow periphery
Flat iris
Bunched up iris in angle
No change in configuration despite LPI

Rx:
- always make sure they have an LPI first
- Argon iridoplasty to pull the iris out of the angle
- miotics

52

DDX of increased EVP

AV malformation: CCF, SWS, orbital varix
Lesion compressing SOV: thyroid, tumor, orbital vein thrombosis, cavernous sinus thrombosis, SVC syndrome
Idiopathic: posture (lying down), familial EVP

53

DDx of blood in Schlemm's

High EVP (AV issues, something compressing SOV)
Hypotony (inflammation, hypotony, following trab)
Normal with compression gonioscopy (occludes episcleral veins)

54

DDx of axenfeld-reiger

ICE
Aniridia
Isolated posterior embryotoxin (N in 15%?)
Peter's anomaly
Ectopia lentis et pupillae (no glaucoma)

55

Systemic findings in axenfeld reiger

Microdontia
Redundant peri-umbilical skin

56

Schabel's optic atrophy def'n and ddx

Hyaluronic acid infiltation of the nerve (stains with colloidal iron, alcian blue)
either from end-stage glaucoma or ischemic optic neuropathy (NAION, AION, etc)

57

Posterior pushing mechanisms of ACG

Choroidal effusions
Vitreous overfill from gas
Ciliary body mass
Supra-choroidal hemorrhage
Malignant glaucoma
Contraction of retro-lental tissue (ROP, PHPV)

58

DDx of NVI/NVA

Fuch's heterochromic iridocyclitis
DM, radiation retinopathy, OIS
CRVO, BRVO, CRAO
RB!!! Always think RB
ROP/FEVR/Eales
Sickle cell

59

Types of ONH analysers

Surface topography - HRT
Cross section - OCT

60

Types of setons

Valved (Ahmed)
Non-valved (Baerveldt, Molteno)

61

Pilocarpine for ACG - what types of ACG?

Really just for pupil block or plateau iris
Everything else you dilate (malignant, CACG, NVG, cyclodialysis)

Also, pilo won't work in IOP > 40 because iris muscle is ischemic. Need to lower IOP first

62

Malignant glaucoma risks

Hyperopia
Female
Nanophthalmos
Previous ACG
Recent surgery (5d)

63

Malignant glaucoma rx

Always do an LPI first to resolve any component of pupil block
Dilate
Decrease IOP with aq suppressants or hyperosmotics
If pseudophake/aphake, can YAG anterior hyaloid face
If phakic, need vitrectomy

64

Injuries with anterior segment trauma

Conj laceration
Scleral perforation
Corneal perforation
Hyphema
Traumatic iritis
Traumatic mydriasis
Angle recession
Cyclodialysis
Iridodialysis
PVD
RT, GRT
RD
Retinal dialysis

65

Nanophthalmos - what do you get in the eye and how do you treat

- Large lens - gives phacomorphic ACG. LPI. Can dilate to pull the lens back a bit.
- Thick sclera - get uveal effusions. Can do sclerectomies
- Malignant glaucoma - LPI, dilate, YAG hyaloid/vitrectomy
- Can also get high EVP from outflow obstruction through thick sclera - aq suppressants

66

Why cycloplege in uveitis

Reduces pain
Reduces PS
Reduces PAS by deepening the AC
Stabilise blood-aq barrier

67

Deadly effects of atropine

Red as a beet, dry as bone, mad as hatter, hot as hades, blind as a bat

Red - vasodilation, flushing, tachycardia
Dry - dry eyes, dry mouth, constipation
Mad - delerium
Hot - fever
Blind - cycloplegia

Rx with acetylcholinesterase inhibitor - e.g. physostigmine

68

Side effects of phospholine iodide

Iris cysts and ASC cataracts

69

Side effects of b-blockers

ASTHMA AND DECREASED HR/heart block
- always ask about asthma and check HR before giving BB

70

Side effects of brimonidine (and C/I)

NEVER GIVE TO CHILDREN - causes respiratory distress/apnoea, CNS depression, hypotension

Adult s/e:
- allergy
- increased HR
- HTN
- vasodilation/flushing

71

Side effects of CAI (and C/I)

Know this cold.

- SJS
- metallic taste
- tingling in hands/feet
- APLASTIC ANEMIA
- renal failure
- metabolic acidosis
- renal stones
- SICKLE CELL CRISIS

Don't give to sickle cell ppl or kidney failure

72

Cloudy cornea infant ddx

G-STUMPED

73

Congenital ocular anomalies with assoc glaucoma

Anterior segment anomalies:
- ICE
- axenfeld reiger
- aniridia
- nanophthalmos, high hyperopia
- microspherophakia

Cornea:
- sclerocornea, megalocornea

Retina:
- PHPV, ROP

Systemic things:
- Lowe's (cataract + glaucoma)
- Rubella (cataract OR glaucoma, never both)

74

Schwartz syndrome

Photoreceptor OS's from old RD clog the TM and cause glaucoma. Resolves after RD repaired.

75

Hemosiderotic glaucoma

Hemosiderin from hyphema/vit hx clog TM

76

Thymoxamine - whats it used for

Causes pupil constriction without shifting iris-lens diaphragm forward. So you can see the effect of un-bunching iris from the angle without changing the position.

Helps you decide if prophylactic LPI would actually be helpful
(never actually used, i don't think)

77

Photophobia/tearing child

Glaucoma
Lid/eyelash malposition
Corneal irritation, trauma, abrasion, infection
Dacryocystitis, congenital NLDO, canalliculitis, etc

78

Congenital glaucoma triad and signs

Tearing, blepharospam, photophobia

enlarged K diam
cloud K
Haab striae (horizontal)
high IOP
high CDR
increasing myopia

79

Definition of congenital vs infantile vs juvenile glaucoma

Congenital = 0-3 mos
Infantile = 3 mos - 3 years
Juvenile = 3 yrs+

80

Descemet tears - diff types

Forceps trauma - vertical
Haab striae (glaucoma) - horizontal
Vogt's striae (KC) - concentric to cone
Hydrops, PBK

81

Options for painful blind eye

Always do yearly B-scan to rule out mass if there's no view

- atropine/PF
- cyclophotocoagulation
- retro-bulbar alcohol or chlorpromazine
- enucleation/evisceration

82

GA effects on IOP measurement

Ketamine and succinylcholine increase IOP
(KISS of high IOP)

Others lower it

83

Glaucoma surgery in kids - when to do what

Medical management is just temporizing in kids. Start with CAI. Never give brimonidine.

- goniotomy - needs clear K
- trabeculotomy - don't need clear K
- trabeculectomy - if the others fail

84

6 reasons to do an LPI

- acute ACG
- prophylactic if other eye has ACG
- occludable angles
- malignant glaucoma
- plateau iris
- if silicone oil in an aphakic eye (do it inferiorly. SO rises so a superior one will get plugged with SO)
- with ACIOL

85

Define false positive

Patient presses the button when there is no stimulus provided

Max acceptable = 30%

86

Define false negative

Patient doesn't press the button despite it being suprathreshold and in the same area as where they previously saw it

Max acceptable = 30%

87

Define fixation loss (2 ways)

1. There's a pupil tracker on most machines that follows where the patients eye is moving

2. Patient sees a spot that's in the blind spot that was already mapped out

Max acceptable = 1/3

88

What is short term fluctuation on VF

10 points are re-tested 2x each
It measures the difference in brightness that the patient responds to

Can reflect inattention or advanced dz

89

What is MD on visual field

Average of the deviation of all the patient's spots from age-matched control. Measure of the total drop in VF (could be due to glaucoma or cataract/etc)

90

What is PSD on visual field

Measure of the standard deviation of the difference in the patient vs age-matched control. An estimate of the depression in the hill of vision

91

How would a scotoma look if BCVA is

Wider and deeper

92

What happens to the VF if pupil

Globally depressed

93

How do you define a scotoma on VF

Area of vision >3 degrees that is depressed >6 db

Or 1 pt on Humphrey > 10 db depressed
or 2 adj points > 5 db each

94

What is the definition of legal blindness

BCVA in the BETTER eye

95

what doubles in FDT

It's basically a bunch of wide stripes that they flicker really fast in different areas of the VF

So it's high temporal frequency, low spatial frequency
What doubles is the temporal frequency

96

What cells do FDT preferrentially test for

M cells (may be affected first in glaucoma so it may be more sensitive as a screening tool than humphrey)

97

What are the 4 types of VF testing algorithms

Acronym - STER (like a STER-case that we know is used in VF testing)

1. Threshold: staircase of up 4 db, then down 2 db until it reverses again
2. Supra threshold: screening test that shows bright spots higher than threshold. Only picks up severe defects as a screening tool.
3. Efficient threshold: estimates threshold for age-matched and tests those first. Subsequent spots up/down based on what was seen. Only one reversal @ each spot (=SITA)
4. Threshold-related: Threshold determined for a few points then hill of vision determined from those. Then shows 6 db brighter at all spots than threshold - i.e. again just a screening tool for mod/adv dz.

98

How do you classify ACG

Primary or secondry, pupil block or not

Primary pupil block: AACG
Primary non pupil block: chronic ACG, plateau iris

Secondary pupil block: phacomorphic, PS, bombe, lens dislocation/microspherophakia, IOL pupil block

Secondary non-pupil block:
- Anterior pulling: PAS, NVG, ICE, PPMD, epithelial downgrowth
- Posterior pushing: choroid (effusion or anterior rotation), vitreous pressure (silicone oil, gas, tumors, aq misdirection), retro-lental membranes (ROP, PHPV)

99

What did GLT show

L = laser, T = timolol

Laser (ALT) vs drops as first line therapy. Both are ok.

100

What did CIGTS show

T = timolol, S = surgery

For initial glaucoma, is medical therapy better or surgery?

Surgery was worse initially but both had equal Va and IOP control and VF changes at 5 years

101

What did EMGT show

T = timolol (vs nothing)

Is lowering IOP even helpful for glaucoma?
Used timolol +/- ALT needed

Answer is yes, obviously.
53% progressed (62% with no rx, 45% with rx)

102

What did AGIS show

S = surgery

This was primarly a surgical trial looking at ALT vs trab in advanced glaucoma that had failed medical therapy.

Results based on race:
- Blacks: ALT is better initially (because they scar a lot - think keloids - so trab is not going to be good)
- Whites: trab is better initially

ALT failure assoc with young age, high IOP
Trab failure: young age, higher IOP, DM, post-op complications (IOP, inflammation, etc)

103

What did TVT show

Looked at people with glaucoma who either had prev cataract or prev trab surgery

Randomized to get a trab (with MMC) or tube as the next step

Both groups did well. Therefore, tubes can be used earlier than previously thought.

104

What did OHTS show

Inclusion: IOP 24-32, normal field, normal nerve

Lowering IOP by 20% reduces progression from 9.5% to 4.5% over 5 years

Risks for progression:
- age
- lower cct (

105

What did NTGS show

Lowering IOP by 30% is helpful in reducing progression

Risks of progression:
- female
- disc hg
- migraine

106

What are the laser settings for ALT

Argon
Spot size 50um
Power 400 mw
Time 0.1 s
50 spots x 180 deg

107

What are the laser settings for SLT

YAG laser on SLT setting
400 um size
power - start at 0.6-0.9 mJ, want champagne bubbles on some shots
50 spots / 180 deg

108

What are the laser settings for iridoplasty

Argon
500 um size
400 mw power
0.5 - 1.0 seconds (whoa, long)

Think of iridoplasty as 10x argon...
same power (400 mw)
10x spot size (500 vs 50)
10x time (1 sec vs 0.1 sec)

109

What is total deviation on VF

Map of deviation of each point from an age-matched control

110

What is pattern deviation on VF

Take the total deviation, subtract the 7th BEST point and apply that subtraction to all points

Should remove media opacities or general depressions and help you see the hill of glaucoma defects

111

Gene for PXF

LOXL-1

112

2 types of outflow and relative contributions

Trabecular = 90%
UVS = 10%
(% vary depending on source)

113

What drops have an effect on which outflows

PG's: increase UVS
Alpha ag: increase UVS
Cycloplegics: increase UVS

Miotics: increase TM outflow

114

Greatest site of resistance to outflow

Juxta-canalicular meshwork (part of UVS pathway)

115

Outflow measurement called what

Tonography

116

Outflow rate normally

0.22-0.28 ul/min/mmHg

117

GAT size

3.06 diam

118

Ideal cct for GAT

520 um

119

How to clean GAT

alcohol wipe

or 5 min soak with:
- 70% etoh
- 1:10 bleach
- 3% hydrogen peroxide

120

Schaeffer grading system for narrow angle

I = narrow
IV = open

121

What supplies ONH

short posterior ciliary arteries

122

NFL supplied by what

recurrent branches from CRA
(everything OPL and forward is from CRA)

123

2 theories of glaucoma damage

1. mechanical: compression of NFL axons from high IOP causes damage
2. ischemic: poor blood flow to NFL axons causes them to die

124

% normals with CDR > 0.6

5%

125

% normals with assym CDR > 0.2

1%

126

Hemifield assymetry on VF

compares top half of VF to bottom half
sup is normally 1-2 db less than inferior
(see better inferiorly)

anything different is suspicious

127

Narrow angle provocative tests

Prone-dark test (30-60 min lying prone in the dark)

128

SLT best for who

Pigmented glaucoma and angles
(PXF and PDS)

129

PDS - risk of glaucoma

25-50%

130

Who gets PDS

young, myopic, males

131

Compare Fuch's vs Posner Schlossman

Fuch's:
- presents with blurred vision
- fine stellate KP
- min AC rxn
- iris heterochromia
- fine angle vessels that bleed easily
- treat IOP, steroids don't really help

PS:
- mild AC rxn
- no KP
- no heterochromia
- episodic unilateral pain
- rx with steroid (IOP should come down on its own)

132

Sickle cell - how to treat IOP

avoid CAI
avoid alpha-1 ag (apraclonidine). alpha-2 ok (brimonidine)

133

Abx in kids - whats not ok

Tetracyclines def not ok

134

When do you get ghost cell glaucoma

1-3 months after vit hx

135

How do you treat ACG from microspherophakia

DILATE the pupil (flattens the lens and pulls it back)

136

How to treat fibrous ingrowth/epi downgrowth over the angle

If blocks the angle, treat with meds first
Can't do laser

137

Rx for topamax induced ACG

dilate the pupil (rotate CB backwards)

138

how to treat glaucoma in pregnancy

All drugs class C except brimonidine (class B)
better to do laser first if you can

Stop brimonidine once she starts nursing

139

ALT stats

Decreases IOP by 20-25%
80% ppl respond
50% success at 5 years (10% per year drop off)

140

Bleb endopht risks

young age
male
blepharitis
dacryocystitis, NLDO

141

Bleb endopht bugs

Strep pneumo, H flu

142

How to treat bleb endophth

tap and inject + fortified topicals
EVS PPV results don't really apply. So might do PPV earlier I think?

143

Rate of aq production

2-3 ul/min = 3 ml/day

144

AC vol

250 ul

145

Fluorophytometry is what

Measures rate of aq production

146

Decreased aq production with:

age
sleep (45% less!)
inflammation, surgery, trauma, meds

147

Aq humor compared to plasma

15X more ascorbate (remember this one)
Less protein, less ca, less phosphorous
everything else the same

148

Blood:CB barrier is...

fenestrated

149

CB = what layers

Inner non-pigmented epithelium (equiv to retina - inner and non-pig)
Outer pigmented epithelium (continuous with RPE - think outer, pigmented)