Pharmacology

Question 1

What is the corneas composition?

Answer 1

lipid:water:lipid

Question 2

What is the compostition of the epithelium?

Answer 2

lipophilic and hydrophobic

Question 3

What types of drugs penetrate the epithelium of the cornea?

Answer 3

hydrophobic drugs - lipid soluble

Question 4

What types of drugs penetrate the stroma of the cornea?

Answer 4

hydrophillic drugs - water soluble

Question 5

What is the compostition of the stroma?

Answer 5

lipophillic and hyodrphillic

Question 6

What type of substance can get through the tear film of the cornea?

Answer 6

lipophilic

Question 7

What type of drug is chloramphenicol?

Answer 7

lipophillic and hydrophilic so penetrates the corena easily

Question 8

What does inflammation do to corneal penetration?

Answer 8

makes it easier as it reduces the hydrophobicness

Question 9

What is the compostion of topical steroids?

Answer 9

hydrophobic and hydrophilic

Question 10

What happens to a drug if it cannot go through the tear film?

Answer 10

it’ll get washed out

Question 11

How do you make a steroid more hydrophobic?

Answer 11

add an alcohol or acetate

Question 12

How do you make a steroid more hydrophilic?

Answer 12

add a phosphate

Question 13

When is prednisolone acetate used? What are its properties?

Answer 13

post op

hydrophobic - good for penetration of an uninflammed cornea

Question 14

When is prednisolone phosphate used? What are its properties?

Answer 14

used for corneal disease or low dose steroid use

hydrophilic - good penetration of an inflammed cornea

Question 15

What is the most common pathogens for eye infections with contact lenses?

Answer 15

pseudomonas

Question 16

What is pseudomonas infection treated with?

Answer 16

Benzalkum chloride - punches out holes in the walls of bacteria but has bad side effects so now use
Bimatoprost 0.1% - benzalkum chloride content of 0.2%

Question 17

What is the side effect of Benzalkum chloride?

Answer 17

strips out a layer of cornea

Question 18

How can you increase topical drug absorption in the eye?

Answer 18

punctal occlusion

Question 19

How can occular injections be done?

Answer 19

either intravitreal or intracameral

Question 20

What happens if antibiotics are injected into the wrong place?

Answer 20

retinal detachment

Question 21

What should steroids NEVER be given to?

Answer 21

Herpes Keratitis

Question 22

When should steroids be used?

Answer 22

post op cataracts - can also cause cataracts tho
uveitis 
preventing corneal graft rejection
temporal arteritis
anterior ischeamic neuropathy

Question 23

What are the local side effects of steroids?

Answer 23

cataracts - reversible
glaucoma
exacerbation of viral infection

Question 24

What are the systemic side effects of steroids?

Answer 24

gastric ulceration
immunosuppression
osteoporosis
weight gain
diabetes
neuropyschiatric effects

Question 25

When are NSAIDs used?

Answer 25

pain relief post refractive laser | cataracts

Question 26

When are antihistamines and mast cell stabalisers used?

Answer 26

hay fever | conjunctivitis

Question 27

What is the aim of glaucoma medication?

Answer 27

unblock the trabecular meshwork or reduce production of aqueous

Question 28

What medications unblock the trabecular meshwork in glaucoma?

Answer 28

prostanoids - latansoprost | alpha-2-adrenergic agonist - brimomidine

Question 29

What medications are used to reduce the production of aqueous humour in glaucoma?

Answer 29

beta blockers - trimolol carbonic anhydrase inhibitors = dorzolamide alpha-2-adrenergic agonists = brimomidine

Question 30

Why can some systemic drugs not enter the eye?

Answer 30

blood - retinal barrier

Question 31

What is endopthalmitis?

Answer 31

white cells in the eye due to surgery | sight threatening

Question 32

How is endopthalmitis treated?

Answer 32

antibiotics intravitreally

Question 33

How do eye local anaesthetics work?

Answer 33

block sodium channels and impede nerve conduction

Question 34

When are local anaesthetics used?

Answer 34

``` forgein body removal tonometry - ICP measurement corneal scraping comfort cataract surgery ```

Question 35

What is the role of mydriatic drugs?

Answer 35

blocks parasympathetic supply to iris causing dilation | also causes cycloplegia - stops the lens focussing

Question 36

What are the side effects of mydriatic drugs?

Answer 36

blurring

Question 37

What are the role of sympathomimetics?

Answer 37

acts on sympathetic system to enhance sympathetics some cause cycloplegia - stops the lens focussing (atropine) some do not - phenylephrine