Pharmacology of the Eye

Question 1

When are topical steroids used?

Answer 1

Post cataract surgery
Uveitis/Iritis
Prevent graft rejection

Question 2

What are the local side effects of steroid in the eye?

Answer 2

Cataracts
Exacerbation of viral infection
Glaucoma

Question 3

What are the systemic effects of steroid use?

Answer 3

Osteoporosis
Weight gain
Immunosuppresion
Moon face
Truncal obesity
Acne
Gastric ulceration
Hypertension

Question 4

How can you make steroids more

a) Hydrophobic/lipophilic
b) Hydrophilic/lipophobic?

Answer 4

a) add acetate/alcohol

b) add phosphate

Question 5

Why is benzalkonium added to topical treatments?

Answer 5

Preservative
Disrupts corneal lipid layer
Aids penetration

Question 6

What drugs can be used in inflammation of the eye?

Answer 6

Steroids
NSAIDS
Anti-histamines
Mast call stabilisers

Question 7

When are NSAIDS used?

Answer 7

Pain relief

Post refractive laser

Question 8

When are anti-histamines used?

Answer 8

Hayfever

Allergic conjunctivitis

Question 9

What are the routes of administration for drugs in the eye?

Answer 9

Topical
Sub-conjunctival
Intracorneal
Sub-tenons
Intravitreal

Question 10

What are the problems with topical drugs?

Answer 10

Lipid layer of tear film impedes penetration

Question 11

How does inflammation affect endothelium?

Answer 11

Makes it less hydrophobic

Question 12

What drugs are given intravitreal?

Answer 12

Anti VEGF
Antibiotics for endophtalmitis
Intraocular steroids

Question 13

Why are intravitreal injections good?

Answer 13

effective concentration to target site

Question 14

Why may intravitreal injections potentially disadvantageous?

Answer 14

Retinal toxicity

Question 15

What colour drops would you use diagnostically?

Answer 15

Flouriscene, orange

Question 16

What can flouriscene be used for?

Answer 16

Diagnosis corneal abrasion
Diagnosis nasolacrimal gland obstruction
Tonometry
Angiography

Question 17

Name 2 dilating drops

Answer 17

Tropicamide

Phenylephrine hydrochloride

Question 18

How does tropicamide cause dilatation?

Answer 18

blocks parasympathetic supply

Question 19

What are the local side effects of topicamide?

Answer 19

Blurred vision

Acute angle closure glaucoma

Question 20

How does phenylephrine hydrochloride cause dilatation?

Answer 20

Acts on sympathetic supply

Question 21

How do local anaesthetics work?

Answer 21

Block Na+ channels

Reduces nerve conduction

Question 22

When are local anaesthetics used?

Answer 22

Foreign body removal
Tonometry
Corneal scraping

Question 23

What is the route of administration in glaucoma medication?

Answer 23

Intravitreal

Question 24

What is the aim of glaucoma medication?

Answer 24

Lower intra-ocular pressure

Question 25

What medications are used in glaucoma?

Answer 25

``` Prostanoids (lantaprost, ie xalantan) Beta blockers Carbonic anhydrase inhibiters (dorcolamide) Alpha 2 agonists Parasympathomemetics (pilocarpine) ```

Question 26

When are antivirals used in eye infections?

Answer 26

Dendritic ulcers

Question 27

What should NOT be used with a dendritic ulcer?

Answer 27

Do not use steroids

Question 28

Give an example of an antiviral used in eyes

Answer 28

Zovirax

Question 29

What is the action of Quinolones?

Answer 29

Inhibits DNA gyrase Unwinds supercoils Causes bacterial death

Question 30

Name a quinolone used in eyes

Answer 30

ofloxacin

Question 31

What is the actoin of penicillins?

Answer 31

Has B-lactam ring Inhibits cell wall producing enzyme Causes cell death

Question 32

What is the action of Chloramphenicol?

Answer 32

Inhibits peptidyl transferase | Stops proteins synthesis via ribosomes

Question 33

What is the route of administration for chloramphenicol?

Answer 33

topical

Question 34

How does chloramphenicol pass through the corneal layers? (Hydrophobic//Hydrophilic//Hydrophobic)

Answer 34

It is both hydrophobic and hydrophilic

Question 35

When is chloramphenicol used?

Answer 35

Bacterocidal in Strep and Haemophilus | Bacterostatic in Staph

Question 36

What are the side effects of Chloramphenicol?

Answer 36

Allergy Aplastic anaemia (irreversible, rare) Grey Baby Syndrome

Question 37

What are the local side effects of a) Vigabatrin b) Steroids c) Ethambutol d) Chloroquine

Answer 37

a) constricts visual feilds b) cataracts c) optic neuropathy d) maculopathy