Pharmacology and the Eye Flashcards Preview

2 Ophthalmology > Pharmacology and the Eye > Flashcards

Flashcards in Pharmacology and the Eye Deck (39)
Loading flashcards...
1
Q

routes of administration for drugs into the eye

A
Topical 
Subconjunctival 
Subtenons 
intravitreal 
intra cameral
2
Q

what is the cornea made up of

A

Lipid:water:lipid sandwich - topical drugs need to be able to get through these layers (lipid and water)

3
Q

what properties is the epithelium of the cornea

A

hydrophobic and lipophilic

therefore penetrated by lipid soluble drugs

4
Q

what properties is the stroma of the cornea

A

lipophobic and hydrophilic

therefore penetrated by water soluble drugs

5
Q

what happens to the cornea in inflammation

A

the cells become leaky and move further apart therefore reducing the hydrophobic nature of the epithelium

6
Q

how can topical steroids be made both hydrophobic and hydrophilic

A

addition of an alcohol/acetate makes it more hydrophilic so it can get through the epithelium

7
Q

how can you make sure a topical steroid acts on just the surface of the eye

A

adding a phosphate makes it more hydrophilic so it can’t get through the epithelium

8
Q

what are the properties of prednisolone acetate

A

lipophilic - gets through the epithelium

struggles to get through the stroma but still does as its still a lil bit hydrophilic

9
Q

what are the properties of prednisolone phosphate

A

hydrophobic

poor penetration in an uniflamed cornea so used during inflammation or if you want low dose steroids

10
Q

what is benzalkonium

A

preservative used in eyedrops to keep the bottle sterile

also aids the penetration of some drugs

strops out the lipid layer of the tear film

11
Q

where can systemic absorption occur with topical eye drugs

A

via the tears into the lacrimal sac and out into the nasopharynx

12
Q

what is subconjunctival administration

A

injection into the conjunctiva

13
Q

what is subtenons administration

A

space through the conjunctiva and through the tendons in the back of the eye

numbs eyes for cataract surgery and can also be used to administer steroids

14
Q

what is intravitral administration

A

needle goes through the ciliary body into the back of the eye

15
Q

what is intracemeral administration

A

puts drug into back of eye

16
Q

what drugs are used to treat inflammation

A

steroids - suppress inflammation, allergy and immune response

topical NSAIDS

Anti-histamines

Mat-cell stabilisers

17
Q

when are steroids commonly used

A

post op cataracts
uveitis
prevents corneal graft rejection
Temporal arteritis

18
Q

what are some local side effects of steroids

A

cataracts
glaucoma
exacerbation of viral infection

19
Q

what are some systemic side effects of steroids

A
gastric ulceration 
immunosuppression 
osteoporosis 
weight gain 
diabetes 
Neuropsychiatric effects 
Cushing's
20
Q

Aims of glaucoma treatment

A

aim to slow down by reducing IOP

Drops work by either stopping the production of aqueous humour or opening up the canal of schlem

21
Q

what do protanoids do (latanoprost)

A

open up the drain

for glaucoma

22
Q

what do beta blockers do in glaucoma

A

stop aqueous humour production

23
Q

what do carbonic anhydrase inhibitors do

A

stop aqueous humour production

24
Q

what do alpha adrenergic agonists do in glaucoma

A

stop aqueous humour and also open up the drain

25
Q

what do parasympathomimetic drugs do (pilocarpine) in glaucoma

A

opens up the drain

26
Q

how is anti-VEGF delivered

A

intravitreal injections

v expensive

27
Q

when are intravitreal antibiotics delivered

A

Endopthalmitis

28
Q

when is local anaesthetic used

A

stops nerve conduction

  • foreign body removal
  • tonometry
  • corneal scraping
  • comfort
  • cataract surgery
29
Q

what is the most commonly used diagnostic dye

A

fluorescein

30
Q

what is fluorescein used for

A
shows corneal abrasion 
dendritic ulcers 
identifies leaks 
tonometry 
diagnosis of nasolacrimal duct obstruction 
angiography
31
Q

what are mydriatic drugs and how do they work

A

pupil dilating drugs

-cause pupil dilation by blocking parasympathetic supply to the spinchter papillae muscle

OR overstimulation of sympathetics

32
Q

what are the side effects of mydriatic drugs

A
vision blurring 
acute glaucoma (rare)
33
Q

symptoms of acute angle closure glaucoma

A

lots of pain
sudden onset headache and vomiting
red eye and mid dilated pupil which doesn’t reaction bc the pressure in eye is too high

34
Q

what are sympathomimetic drugs

A

drugs which over stimulate the sympathetic nerves causing dilation

some cause paralysis of the ciliary muscle (atropine) however some dont

35
Q

when should topical steroids NEVER be used

A

in patients with HERPETIC keratitis

36
Q

what does an allergy to eyedrops present as

A

symmetrical redness in each eye and around the eye

37
Q

what does vigabatrin do

A

constricts visual fields - can be v painful

anticonvulsant used to treat seizures

38
Q

what drug cause optic neuropathy

A

ethambutol (TB drug)

damages the optic nerve

39
Q

what drug can cause maculopathy

A

chloroquine and hydropxychoroquine (RA drug)

looks like bulls eye on the macula