Occular Pharmacology

Question 1

what are the properties of the epithelium of the cornea?

Answer 1

lipophilic and hydrophobic

Question 2

what are the properties of the stroma of the cornea?

Answer 2

lipophobic and hydrophilic

Question 3

what layer of the cornea do lipid soluble drugs penetrate?

Answer 3

the epithelium

Question 4

what layer of the cornea do water soluble drugs penetrate?

Answer 4

the stroma

Question 5

why is Chloramphenicol particularly good at penetrating the cornea?

Answer 5

it has lipophilic and hydrophilic properties

Question 6

what can reduce the hydrophobic nature of the endothelium of the cornea?

Answer 6

ocular surface inflammation

Question 7

what type of drugs does the epithelium of the cornea limit?

Answer 7

hydrophilic drugs

Question 8

what type of drugs does the stroma of the cornea limit?

Answer 8

hydrophobic drugs

Question 9

what affect does adding alcohol or acetate to a steroid have?

Answer 9

makes it more hydrophobic

Question 10

what affect does adding phosphate to a topical steroid have?

Answer 10

makes it more hydrophilic

Question 11

does prednisolone acetate have a good or bad penetration in an uninflamed cornea?

Answer 11

good penetration

Question 12

when is prednisolone acetate most often used?

Answer 12

post-operatively

Question 13

does prednisolone phosphate have a good or poor penentration in an uninflamed cornea?

Answer 13

poor

Question 14

what is prednisolone phosphate used for?

Answer 14

for cornea disease or when u want low dose steroid

Question 15

why is benzalkonium added to eye treatment bottles?

Answer 15

it is a preservative

Question 16

other than being a preservative, what else does benzalkonium do?

Answer 16

disrupts lipid layer of tear film- therefore aids penetration of some drugs

Question 17

how long do bottles of eye treatment last before they are no longer effective?

Answer 17

about 4 weeks

Question 18

how can eye drops be systemically absorbed and where does this happen?

Answer 18

tears are pumped out of lacrimal sac rapidly and excess goes to systemic absorption in the nasopharynx

Question 19

what are the 4 types of injections?

Answer 19

subconjuctival and subtenons. Intravitreal and intracameral

Question 20

when are topical steroids used?

Answer 20

• post op cataracts
• uveitis
• to prevent corneal graft rejection

Question 21

what are the possible local side effects of topical steroids?

Answer 21

• cataract
• glaucoma
• exacerbation of viral infection

Question 22

what are the possible systemic side effects of topical steroids?

Answer 22

-gastric ulceration
-immunosuppression
-osteoporosis
-weight gain
-diabetes
etc

Question 23

currently, what is the only modifiable risk factor for glaucoma?

Answer 23

raised intra ocular pressure

Question 24

what happens in glaucoma?

Answer 24

progressive damage to the optic nerve resulting in visual field defects

Question 25

what is the gold standard 1st line managment for glaucoma?

Answer 25

Prostanoids

Question 26

Give an example of a Prostanoid?

Answer 26

Latanoprost (Xalatan)

Question 27

other than Prostanoids, what other treatments can be given in glaucoma?

Answer 27

- beta blockers - carbonic anhydrase inhibitors - alpha2 adrenergic agonist - parasympathomimetic

Question 28

examples of beta blockers used in glaucoma?

Answer 28

timolol, betaxolol, levobunolol, carteolol

Question 29

give an example of a topical carbonic anhydrase inhibitors?

Answer 29

Dorzolamide

Question 30

give an example of a systemic carbonic anhydrase inhibitors?

Answer 30

acetazolamide

Question 31

Give an example of alpha2 adrenergic agonist ?

Answer 31

brimonidine

Question 32

an example of a parasympathomimetic?

Answer 32

pilocarpine

Question 33

what method of admission is used in endophthalamitis and what is given?

Answer 33

antibiotics given intravitreally

Question 34

what does anti-VEGF stand for?

Answer 34

anti- Vascular-endothelial growth factor

Question 35

what is the most common cause of endopthalmitis?

Answer 35

post-op or post-injection.

Question 36

how does a local anaesthetic work in the eye?

Answer 36

blocks sodium channels and impedes nerve conduction

Question 37

why should you not give eyedrop local anaesthetic home with someone?

Answer 37

it impairs healing

Question 38

what is most commonly used diagnostic dye?

Answer 38

fluorescein

Question 39

what are the 4 uses of fluroscein dye?

Answer 39

- shows corneal abrasion - tonometry - diagnosing nasolacrimal duct obstruction - angiography

Question 40

what is the purpose of using a mydriatics?

Answer 40

to dilate the pupil while examining

Question 41

how do mydriatics cause pupil dilation?

Answer 41

by blocking parasympathetic supply to iris

Question 42

what is the common side effects of giving mydriatics?

Answer 42

blurred vision

Question 43

what is an extremely rare side effect of mydriatics?

Answer 43

AACG- acute angle closure glaucoma

Question 44

what is the main feature of AACG?

Answer 44

a banging headache

Question 45

what does a sympathomimetic work on and what is the effect?

Answer 45

acts on systemic system and causes pupil to dilate

Question 46

give 2 examples of sympathomimetics?

Answer 46

phenylephrine and atropine

Question 47

what drug has been associated with causing optic neuropathy?

Answer 47

ethambutol used in TB

Question 48

what is chloroquine associated with causing?

Answer 48

maculopathy

Question 49

2 examples of mydriatics?

Answer 49

tropicamide and cyclopentolate