Glaucoma

Question 1

What is the intraocular pressure maintained at?

Answer 1

10 - 20 mmHg

Question 2

When does intraocular pressure increase and by how much?

Answer 2

over the age of 40

1 mmHg every decade

Question 3

When is intraocular pressure at a max and min?

Answer 3

max - 8-11 am

min midnight to 2pm

Question 4

What is aqueous humour indirectly related to?

Answer 4

blood pressure and blood flow in the ciliary body

Question 5

What is the adrenergic receptor for the iris radial muscle?

Answer 5

alpha 1

Question 6

What is the adrenergic receptor subtype for the ciliary epithelium?

Answer 6

alpha 2 and beta 2

Question 7

Adrenergic receptor for ciliary muscle?

Answer 7

beta 2

Question 8

Adrenergic receptor for lacrimal gland?

Answer 8

alpha 2

Question 9

5 types of glaucoma?

Answer 9

1. chronic open-angle glaucoma (COAG)
2. normal tension glaucoma
3. ocular hypertension (OHT)
4. primary angle-closure glaucoma
5. secondary glaucoma

Question 10

What happens in COAG?

Answer 10

obstruction of aqueous outflow
through trabecular network
both eyes

Question 11

Normal tension glaucoma?

Answer 11

IOP not seen on 1st screening

signs of damage

Question 12

ocular hypertension?

Answer 12

elevated IOP in absence of visual field loss

or optic nerve damage

Question 13

What is glaucoma caused by?

Answer 13

poor drainage of aqueous humour

Question 14

What is IOP increased to in glaucoma?

Answer 14

> 21 mmHg

Question 15

What happens to the fundus in glaucoma?

Answer 15

optic disk ‘cupping’

Question 16

What type of drugs are ocular prostanoids?

Answer 16

ester compounds

Question 17

What do ocular prostanoids do?

Answer 17

decrease IOP by increasing the uveoscleral outflow

Question 18

Which prostanoid used when patient allergic to the preservatives?

Answer 18

tafluprost

it has no preservatives

Question 19

What happens to lasanoprost in the body?

Answer 19

converted to its active free acid on entering the eye

Question 20

How does travosprost work?

Answer 20

ester prodrug converted to its active form by corneal hydrolytic enzymes as it’s absorbed from the eye

Question 21

How does bimatoprost work?

Answer 21

lowers IOP

sustained for 4 years

Question 22

What other type of drugs are used?

Answer 22

beta adrenoceptor antagonists

Question 23

What do beta blockers do?

Answer 23

block ciliary beta receptors
prevent the cyclic AMP induced rise in aqueous solution
reduce aqueous humour formation rather then increase outflow

Question 24

Which beta blocker is cardioselective?

Answer 24

betaxolol

careful with heart problems

Question 25

What side effects doe beta blockers have?

Answer 25

bradycardia orthostatic hypotension and syncope in elderly avoid in patients with normal tension glaucoma bronchospasm

Question 26

What treatment is first line?

Answer 26

prostaglandin analogues

Question 27

What is mydriasis?

Answer 27

dilation of the pupil

Question 28

2 sympathomimetic agents

Answer 28

apraclonidine | brimonidine

Question 29

What type of drug is apraclonidine?

Answer 29

alpha 2 selective agonist

Question 30

What does apraclonidine do in high concentrations?

Answer 30

activates alpha 1 receptors | decreases ciliary blood flow

Question 31

What part of the eye does apraclonidine work on?

Answer 31

ciliary body | decreases aqueous humour

Question 32

Is apraclonidine used on its own?

Answer 32

no, adjunctive therapy

Question 33

When is apraclonidine used?

Answer 33

0.5% solutions used for short term therapy adjunctive treatment patients on max tolerated therapy to delay laser treatment or surgery

Question 34

How does brimonidine work?

Answer 34

alpha 2 selective | results in miosis (pupil constriction)

Question 35

Is brimonidine used on its own?

Answer 35

yes or with beta blockers and PGA

Question 36

What does brimonidine do?

Answer 36

decreases aqueous humour production | increases uveoscleral flow

Question 37

When is brimonidine contraindicated?

Answer 37

in patients taking MAOIs or TCAs (antidepressants) | caution in severe CAD

Question 38

Miotic drug

Answer 38

pilocarpine

Question 39

How does pilocarpine work?

Answer 39

increases outflow of aqueous humour | opens channels of trabecular meshwork

Question 40

What is pilocarpines duration of action?

Answer 40

short, 4 times daily | onset of action 19 mins

Question 41

What types of glaucoma is pilocarpine used in?

Answer 41

COAG | secondary glaucoma

Question 42

Where do carbonic anhydrase inhibitors work?

Answer 42

in ciliary epithelium

Question 43

How do carbonic anhydrase inhibitors work?

Answer 43

- inhibit CA-II - slows formation of bicarbonate ion and its secretion into posterior chamber - decreases Na transport into posterior chamber - lowers IOP

Question 44

3 types of carbonic anhydrase inhibitors

Answer 44

acetazolamide dorzolamide brinzolamide

Question 45

2 types of hyperosmotic agents

Answer 45

glycerol | mannitol

Question 46

When are hyperosmotic agents used?

Answer 46

PACG emergency

Question 47

How are glycerol and mannitol administered?

Answer 47

glycerol - oral | mannitol - IV

Question 48

How do hyperosmotic agents work?

Answer 48

move water out of vitreous humour reduce IOP deepen the anterior chamber

Question 49

Symptoms of PACG

Answer 49

``` severe pain nausea redness blurred vision blindness within 2 days if not treated ```

Question 50

Permanent cure of PACG

Answer 50

laser surgery

Question 51

Iredectomy

Answer 51

hole in iris increases flow of aqueous humour laser surgery

Question 52

What laser is used?

Answer 52

YAG - Yttrium aluminum garnet