Pharmacology

Question 1

When is the topic route of administration used in eye diseases?

Answer 1

Required to act on surface

Require corneal penetration

Question 2

What is the cornea made up from?

Answer 2

Lipophilic epithelium

Lipophobic stroma

Question 3

What are the chemical properties of chloramphenicol?

Answer 3

Lipophilic and hydrophilic

Question 4

What effect can ocular surface inflammation have on the nature of the endothelium?

Answer 4

Reduce the hydrophobic nature

Lipid layer of tear film may impede drug penetration

Question 5

What are hydrophilic drugs limited by?

Answer 5

Epithelium

Question 6

What are hydrophobic drugs limited by?

Answer 6

Stroma

Question 7

How are steroids made more hydrophobic?

Answer 7

Addition of an alcohol or acetate

Question 8

How are steroids made more hydrophilic?

Answer 8

Phosphate

Question 9

When is prednisolone acetate used?

Answer 9

Good penetration in uninflamed cornea

Used post-op in cataract surgery

Question 10

When is prednisolone phosphate used?

Answer 10

Poor penetration in uninflamed cornea

Used for cornea disease or when low dose steroids are wanted

Question 11

What is benzalkonium?

Answer 11

Used as a surfactant and bacterial agent in prescription bottles to prevent growth of pseudomonas

Question 12

What is the downside/ benefit of benzalkonium?

Answer 12

Disrupts lipid layer of tear film which can aid penetration of drugs but also can cause a dry eye

Question 13

What is bimatoprost?

Answer 13

Drug used to lower IOP in glaucoma

Question 14

How can topical eye drops by systemically absorbed?

Answer 14

Tears are pumped out of lacrimal sac and can be absorbed systemically at the nasopharynx

Question 15

What can be done to prevent systemic absorption of topical drugs?

Answer 15

Punctal occlusion

Question 16

How can injections in the eyes be given?

Answer 16

Subconjunctival
Subtenons
Intravitreal
Intracameral

Question 17

What drops are commonly given for treatment of infections?

Answer 17

Chloramphenicol in the drop and ointment form
Aciclovir
Ofloxacin

Question 18

How is ocular inflammation treated?

Answer 18

Dexamethasone drops 
Prednisolone drops
Topical NSAIDs
Anti-histamines
Mast cell stabilisers

Question 19

When are ocular steroids used?

Answer 19

Post op cataracts
Uveitis
Prevention of corneal graft rejection

Question 20

What are the local ocular side effects of steroids?

Answer 20

Cataract
Glaucoma
Exacerbation of herpes simplex conjunctivitis - corneal melt

Question 21

What are the systemic side effects of steroids?

Answer 21

Gastric ulceration - prescribe with proton pump inhibitor
Immunosuppression
Osteoporosis
Weight gain
Diabetes
Neuropsychiatric effects

Question 22

What is glaucoma?

Answer 22

A group of diseases characterised by a progressive optic neuropathy resulting in characteristic field defects
Raised IOP only modifiable risk factor

Question 23

What can be seen on the optic disc in glaucoma?

Answer 23

Cupping

Question 24

What meridian line will glaucoma tend to respect?

Answer 24

The horizontal line - affects the superior or inferior fields

Question 25

What glaucoma drugs will work to open the trabecular meshwork/ canal of schlemm?

Answer 25

Prostanoids e.g. latanoprost Alpha adrenergic agonists e.g. brimonidine Parasympathomimetic e.g. pilocarpine

Question 26

What glaucoma drugs will work to reduce the production of aqueous humor?

Answer 26

Beta blockers e.g. timolol Carbonic anhydrase inhibitors e.g. dorzolamide Alpha adrenergic agonists e.g. brimonidine

Question 27

What are the advantages to intravitreal injections?

Answer 27

Delivers effective concentration of drug at target site but many drugs are toxic to the retina Used as a method of administration of antibiotics in endophthalmitis Intra-ocular steroids Anti-VEGF in wet ARMG

Question 28

What can be seen in endophthalmitis?

Answer 28

Hypopyon - pus fluid level in eye | Surgical complication

Question 29

What are common diagnostic drops?

Answer 29

Proxymetacaine hydrochloride | Fluorescein

Question 30

What are common dilating drops used?

Answer 30

Tropicamide Phenylephrine Atropine Cyclopentolate

Question 31

How do local anaesthetic drops work?

Answer 31

Blocks sodium channel to impede nerve conduction

Question 32

When are local anaesthetic drops used?

Answer 32

``` FB removal Tonometry (IOP measurement) Corneal scraping Comfort Cataract surgery ```

Question 33

When are fluorescein drops used?

Answer 33

``` Corneal abrasion Dendritic ulcer (herpes simplex keratitis) Identify leaks - seidel's test Tonometry Diagnose nasolacrimal duct obstruction Angiography ```

Question 34

How do mydriatics (tropicamide, cyclopentolate) work?

Answer 34

Cause pupil dilation by blocking parasympathetic supply to iris Cause cycloplegia

Question 35

What are the symptoms of acute angle closure glaucoma?

Answer 35

``` High pressure in eye Acute red eye High pain N+V Headache Dilated pupil that is not reactive ```

Question 36

How do sympathomimetics (atropine and phenylephrine) work to dilate the eye?

Answer 36

Acts on symp system to cause dilation | Atropine will cause cycloplegia

Question 37

What is cycloplegia?

Answer 37

Can't accomodate

Question 38

What is the max effect and recovery from atropine drops?

Answer 38

Max effect: 30-40 mins | Recovery: 7-9 days

Question 39

What is the max effect and recovery from cyclopentolate?

Answer 39

Max effect: 30-60 mins | Recovery: 8 hours

Question 40

What is the max effect and recovery from phenylephrine?

Answer 40

Max effect: 20-60 mins | Recovery: 6 days

Question 41

What is the max effect and recovery from tropicamide?

Answer 41

Max effect: 20-40 mins | Recovery: 6hrs to 1 day

Question 42

What TB drug can cause optic neuropathy?

Answer 42

Ethambutol

Question 43

What drug can cause maculopathy?

Answer 43

Chloroquine - never see this now as only prescribe hydroxychloroquine

Question 44

What can amiodarone cause in the eye?

Answer 44

Vortex keratopathy