Glaucoma

Question 1

Glaucoma

Answer 1

Characteristic changes in the optic nn head –> loss of visual field

Question 2

Where is aq humour produced?

Answer 2

Ciliary body

Question 3

How does aq drain?

Answer 3

Via trabecular meshwork

Question 4

Where does the aq go after the trabecular meshwork?

Answer 4

Schlemm’s canal –> collecting channels –> venous system

Question 5

What is normal intraocular pressure?

Answer 5

10-22mmHg

Question 6

How much can IOP vary throughout the day?

Answer 6

by 5mmHg

Question 7

When is IOP the highest?

Answer 7

At night

In the morning

Question 8

What 2 things are IOP determined by?

Answer 8

Rate aq production

Resistance aq drainage

Question 9

Which structural changes would suggest glaucoma (4)

Answer 9

Incr cup size
Asymmetrical cupping
Notching rim, vertical elongation
Vessels nasally displaced, bayonetted

Question 10

What is the ISNT rule?

Answer 10

In normal disc:

Size inferior > superior > nasal > temporal

Question 11

How do you test IOP?

Answer 11

Goldmann tonometer

Question 12

What is a normal cup: disc

Answer 12

0.3

Question 13

What is the normal colour of the optic disc?

Answer 13

Salmon pink

Question 14

What are the 2 types of glaucoma?

Answer 14

Primary open angle glaucoma

Acute angle closure glaucoma

Question 15

What Sx do you get with POAG?

Answer 15

Visual field defects (peripheral initially)

Question 16

What % >40s have POAG

Answer 16

1%

Question 17

What % >75s have POAG?

Answer 17

5%

Question 18

Risk Factors POAG (6)

Answer 18

Raised IOP
FHx 
Myopia 
Afro-Carribean 
DM
Steriods

Question 19

What cup:disc would be definitely pathological?

Answer 19

0.7

Question 20

What happens to the optic disc colour as POAG progresses?

Answer 20

Disc becomes pale

Question 21

What is a physiological scotoma? Where is it

Answer 21

Blind spot

@ optic disc, 15’ temporally

Question 22

How is the open angle measured?

Answer 22

gonioscopy

Question 23

E.g.s of drugs used to Tx POAG

Answer 23

PG analogues - TO latanoprost 
B-blockers - timolol drops 
A-adrenergic - Apraclonidine drops 
CAH inhibitors - dorzolamide, acetazolamide 
Miotics - pilocarpine TO

Question 24

Surgical options for POAG (2)

Answer 24

Argon laser trabeculoplasty

Surgical trabeculectomy

Question 25

Action latanoprost

Answer 25

Increases uveoscleral aq outflow

Question 26

SE latanoprost

Answer 26

Red eye Iris colour change Eyelash growth Periocular skin pigmentation

Question 27

Action timolol

Answer 27

Decr aq production

Question 28

SE timolol

Answer 28

``` Dry eyes Corneal anaesthesia Bradycardia Bronchospasm Depression ```

Question 29

Action Apraclonidine

Answer 29

Decr aq production | Incr uvescleral outflow

Question 30

SE apraclonidine

Answer 30

``` Mydriasis Lethargy Dry mouth HTN risk hypertensive crisis if on MAOIs ```

Question 31

Action dorzolamide

Answer 31

Decr aq production

Question 32

SE dorzolamide

Answer 32

Pain | Local allergic reaction

Question 33

When should use of acetazlamide be used ith caution>

Answer 33

pregnancy | renal stones Hx

Question 34

SE acetazalimide?

Answer 34

Met acidosis Hypokalaemia Paraesthesia GI disturbance

Question 35

Action pilocarpine

Answer 35

Contricts pupil, unblocks trabecular meshwork

Question 36

C/I pilocarpine

Answer 36

Ant uveitis High myopia Retinal detachment Aphakia

Question 37

SE pilocarpine

Answer 37

Decr acuity | Brow ache for ciliary mm spasm

Question 38

Pathophysiology of acute angle closure glaucoma

Answer 38

Lens becomes pushed against iris --> pupillary block Build up of aq in posterior chamber + bulging of iris + closure of iridocorneal angle Blocks trabecular meshwork

Question 39

Risk factors AACG (4)

Answer 39

F (4:!) Asians Shallow anterior chamber Shorter axial length

Question 40

2' causes of AACG

Answer 40

Uveitis NV - DM, retinal vv occlusion Pigment dispersion syndrome Traumatic hyphaema

Question 41

Sx AACG (4)

Answer 41

Pain N+V Blurred vision Halo's

Question 42

Signs AACG (5)

Answer 42

``` Brick red eye Cloudy cornea Fixed mid-dilated pupil IOP >21mmHg Closed iridocorneal angle on gonioscopy ```

Question 43

3 Mx steps of AACG

Answer 43

Topical Systemic Laser Tx

Question 44

Eye drops used AACG

Answer 44

Timolol | Apraclonidine

Question 45

Once IOP in AACG is <50 what should you prescribe?

Answer 45

Miotic

Question 46

Systemic Tx AACG

Answer 46

IV CAH - acetazolamide IV hyperosmotic e.g. mannitol Analgesia, antiemetics

Question 47

When to use laser trabeculectomy in AACG

Answer 47

ASAP in contralateral eye | + within a week in eye affected

Question 48

When to use trabeculectomy in AACG?

Answer 48

Resistant cases