DIS - Open Angle Glaucoma II - Week 3

Question 1

Why can drance haemorrhaging occur?

Answer 1

Loss of glial support leads to vascular compromise

Question 2

Define drance haemorrage.

Answer 2

Any haemorrhage up to 1 DD away from the disc

Question 3

What can drance haemorrhages precede (2) and by how many years?

Answer 3

Can precede VF and RNFL loss by 2-5 years

Question 4

What is a very common casue of drance haemorrages?

Answer 4

High systemic blood pressure

Question 5

Are drance haemorrhages easy to spot or easy to miss?

Answer 5

Easy to miss

Question 6

What effect does losses in neural tissue have on blood vessels?

Answer 6

they kink

Question 7

How does PPA occur?

Answer 7

Loss of deep choroidal blood flow gives overlying atrophy

Question 8

What type of glaucoma is PPA common in?

Answer 8

Low tension glaucoma

Question 9

What should be noted with gliosis and the B/D/B feature of the RNFL?

Answer 9

Gliosis can give sheen in advanced loss

Question 10

When assessing B/D/B for RNFL, do you see individual nerves?

Answer 10

no, you see bundles

Question 11

Which section appears darkest when assessing B/D/B RNFL?

Answer 11

Nasald

Question 12

What is B/D/B RNFL harder to detect with (3)?

Answer 12

Catarac
Age
High myopia

Question 13

Can you have localised loss with B/D/B RNFL or only generalised loss?

Answer 13

Yes, you get a wedge loss appearance

Question 14

What clinical procedure is best for advanced/severe cases of glaucoma?

Answer 14

Visual fields

Question 15

Must all methods be used for detection? List them (4) and note which is better.

Answer 15

RNFL OCT
Macula GCC OCT
ON appearance OCT/photo
Visual fields
RNFL OCT is better than NRR photos

Question 16

Describe the following visual field stages by MD and foveal threat:
Mild
Moderate
Advanced

Answer 16

Mild - MD >-6 dB or any central points 15-25 dB
Moderate - MD >-6 dB or any central points 1-15 dB
Severe - MD >-12 dB or one or more central points ≤0 dB

Question 17

Are clusters of abnormal points by healthy individuals normal in visual field tests? What about a repeated test with the same cluster in the same location ? What is the likelihood of 2 such repeated tests?

Answer 17

A cluster of three abnormal points at any single test is made by 58% normals
1 repeated VF test with a 3 point cluster in the same location is borderline normal (8% normal)
2 repeated VF tests is not found in normals (0%)

Question 18

If a VF test is abnormal, how long until the repeat VF test?

Answer 18

1 month

Question 19

AAre VF tests noisy?

Answer 19

Yes

Question 20

Can VF tests find defects earlier than ON photos?

Answer 20

Yes but only when repeated (earlier 36% of the time)

Question 21

What can RNFL OCT often give myopes?

Answer 21

Red disease - false positive

Question 22

What should be used in myopic glaucoma suspects?

Answer 22

VF, mac RGC complex or ON NRR (or both)

Question 23

What three techniques are best for progresison and change? What is best for moderate/severe cases?

Answer 23

RNFL, ON (NRR), VF
VF is best for moderate/severe cases

Question 24

Use the SOAP acronym on primary open angle glaucoma:
S (2)
O (4)
A (5)
P (3)

Answer 24

Subjective
-no symptoms, reduced VF
Objective
-nornal ON colour with NRR loss or RNFL defect
-typical VF defect (need x2 baseline for monitoring)
-open unoccluded angle
-IOP >21mmHg at some stage
Assessment
-work out risk
-disc/NFL imaging
-VF
-Gonioscopy
-IOP
Plan
-treat and monitor
-reduce IOP to target - meds and surgery referral

Question 25

How are visual field defects typically in low tension glaucoma vs primary open angle glaucoma (2)?

Answer 25

Deeper and more central (often foveal threat)

Question 26

What must be done for low tension glaucoma?

Answer 26

Must do a diurnal IOP curve

Question 27

What is the likely cause of low tension glaucoma?

Answer 27

Vascular cause

Question 28

If there is a mild loss in low tension glaucoma, what is the management?

Answer 28

Monitor 3 monthly for one year, then yearly

Question 29

Are beta-blockers ideal for low tension glaucoma?

Answer 29

No, dont use them

Question 30

Can you have low tension glaucoma with an IOP of >21mmHg?

Answer 30

No, low tension glaucoma can never have IOP >21, it must be <22mmHg

Question 31

When assessing the posterior pole for glaucoma, what are three things that can affect VF or NRR/RNFL to look like glaucoma?

Answer 31

Gongenital ON anomalies
Vascular conditions at the ON or RNFL
Tumours or masses along the RNFL

Question 32

List three congenital ON anomalies that can look like glaucoma. How do these affect VF and in what region? Appearance-wise (and with OCT) is it ambiguous or unambiguous for a non-glaucoma cause?

Answer 32

Tilted disc
ON drusen
ON pit/coloboma
These can give VF defects in the arcuate region, similar to glaucoma
The disc appearance & OCT is unambiguous for a non-glaucoma cause

Question 33

List two vascular causes that can look like glaucoma. What VF defects do they involve and what appearance can the disc have? What technique can find these causes? What may be needed for management?

Answer 33

Branch retinal vein occlusion
Anterior ischaemic optic neuropathy
Both can give VF defects that involve arcuate regions and a disc appearance for cupping
Cause found with good ophthalmoscopy
OCT may be needed for management

Question 34

With anterior ischaemic optic neuropathy, distinguish between arteritic and non-arteritic in terms of ONH appearance

Answer 34

Arteritic - cupping
Non-arteritic - no cupping

Question 35

List 4 key signs for vascular causes that look like glaucoma.

Answer 35

NRR has pallor and/or swollen
APD
CV loss
VA loss

Question 36

List three RNFL/ON/pathway disruptions that can look like glaucoma (what type specifically). What VF defects do they involve? Do these have fast or slow progression in VF (give numbers)?

Answer 36

Eye tupour or RD (choroidal melanoma)
ON tumour
Pituitary tumour
These can give VF defects consistent with LTG that involve arcuate regions
Shows fast progression Md > 2 dB/yr

Question 37

What is essential for RNFL/ON/pathway disruptions that can look like glaucoma (any why)? If this is normal, what should be done? What problem does the patient often have? Give four key signs.

Answer 37

BIO essential - may be retinal
-if normal, scan anterior pathway
Often have a reading problem
Key signs - optic atrophy, RAPD, VA loss, CV loss