Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Year 2 Pharmacology > Ocular Pharmacology > Flashcards

Ocular Pharmacology Flashcards

1
Q

Requirements for topical administration of drugs to the eyes?

A

Required to act on the surface

Require corneal penetration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which drugs can effectively penetrate the cornea?

A

LMW drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Nature of the epithelium and which drugs can penetrate it?

A

Epithelium is lipophilic/hydrophobic

Lipid-soluble drugs penetrate the epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Nature of the stroma and which drugs can penetrate it?

A

Stroma is lipophilic/hydrophilic

Water-soluble drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which drugs have both lipophilic and hydrophilic properties?

A

Chloramphenicol; these drugs easily penetrate the cornea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does ocular surface inflammation affect the epithelium?

A

Often REDUCES the hydrophobic nature of the endothelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

So which drugs are limited by which layer of the eye (in terms of penetration)?

A

Hydrophilic drugs are limited by the epithelium

Hydrophobic drugs are limited by the stroma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What chemical modifications can be made to topical steroids to alter their characteristics?

A

Alcohol or acetate - makes steroid more hydrophobic

Phosphate - makes steroid more hydrophilic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Uses of prednisolone acetate?

A

Hydrophobic and so achieves good penetration in an uninflamed cornea, i.e: it is not washed away by tears

It is used post-operatively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Uses of prednisolone phosphate?

A

Hydrophilic and so only achieves poor penetration in an uninflamed cornea, i.e: it is washed away in the tears

Used for corneal disease or for when low-dose steroids are desired

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is benzalkonium?

A

A preservative in eye products that disrupts the lipid later of tear film, causing dry eyes

It also aids the penetration of some drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is Bimatoprost?

A

Drugs used to lower the intra-ocular pressure in glaucoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does systemic absorption of topical drugs occur?

A

Tears are pumped out of the lacrimal sac rapidly but the excess gains systemic absorption at the nasopharynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How can systemic absorption of topical drugs be limited?

A

By punctal occlusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Routes of administration of drugs

A

Subconjunctival

Subtenons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Routes of administration of ocular injections?

A

Intravitreal

Intracameral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Anti-inflammatory drugs that can be used?

A

Steroids

Topical NSAIDs (can be used for pain relief, e.g: post-refractive laser)

Anti-histamines (used in allergic conjunctivitis/hayfever)

Mast cell stabilisers

18
Q

When are steroids used topically?

A
  1. Post-operative cataracts
  2. Uveitis
  3. Prevention of corneal graft injection
19
Q

Local (ocular) side effects of steroids?

A

Cataract, glaucoma and exacerbation of viral infection

20
Q

Systemic side effects of steroids?

A

Gastric ulceration

Immunosuppression

Osteoporosis

Weight gain, diabetes

Neuropsychiatric effects, etc

21
Q

Varying strengths of topical steroids?

A
  1. Fluorometholone (FML)
  2. Predsol
  3. Betamethasone
  4. Dexamethasone/prednisolone
22
Q

What is glaucoma?

A

Group of diseases characterised by progressive optic neuropathy, resulting in characteristic field defects

Cause is intra-ocular pressure

23
Q

Symptoms of glaucoma?

A

Usually asymptomatic until advanced disease stage

24
Q

How do glaucoma drops occur?

A

Drugs that either:

  1. Decrease aqueous humor production
  2. Increase aqueous humor outflow
25
Q

Examples of drugs used in glaucoma treatment?

A

Prostanoids, e.g: latanoprost

β-blockers

Carbonic anhydrase inhibitors:
• Topical - Dorzolamide
• Systemic - Brimonidine

Parasympathetic, e.g: pilocarpine

Combination drugs (dorzolamide and timolol)

26
Q

Uses of intravitreal injections?

A

Method of administration of antibiotics in endophthalmitis

To deliver intra-ocular steroids

Anti-VEGF (anti-vascular endothelial growth factor) - prevents growth of new vessels

27
Q

Advantages and disadvantages of intravitreal injections?

A

Delivers effective concentration of drug at the target site instantly

BUT

Many drugs are toxic to the retina

28
Q

Complication of endopthalmitis?

A

Blindness

29
Q

What is dry macular degeneration?

A

ATROPHIC type

Unknown aetiology

30
Q

What is wet macular degeneration?

A

New vessel membrane forms over the macula; these haemorrhage and leak, leading to damage of the macula

31
Q

Mechanism of action of local anaesthetic in the eye?

A

Blocks Na+ channels and impedes nerve conduction

32
Q

Uses of local anaesthetic?

A
  1. Foreign Body (FB) removal
  2. Tonometry (IOP measurement)
  3. Corneal scraping
  4. Comfort
33
Q

Uses of diagnostic dyes?

A

Most commonly used is fluorescein

Uses include:

  1. Showing a corneal abrasion
  2. Tonometry
  3. Diagnosing a nasolacrimal duct obstruction
  4. Angiography
34
Q

What are mydriatics?

A

Cause pupil dilatation by blocking the parasympathetic supply to the iris, e.g: tropicamide and cyclopentolate

35
Q

Side effects of mydriatics?

A

Blurring

AACG (Acute Angle Closure Glaucoma)

36
Q

How do sympathomimetics work?

A

Act to enhance the sympathetic nervous system, causing the pupils to dilate, e.g: phenylephrine, atropine

They do not affect ciliary muscle (accommodation)

37
Q

Example of a drug that constricts the visual fields?

A

Vigabatrin

38
Q

Example of a drug that can cause a cataract?

A

Steroids

39
Q

Example of a drug that can cause optic neuropathy?

A

Ethambutol

40
Q

Example of a drug that can cause maculopathy?

A

Chloroquine

41
Q

Example of a drug that can cause corneal opacities in the eye?

A

Amiodarone - appears as a horizontal pigmented line

Year 2 Pharmacology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions