Flashcards in Opthalmology pharmacology Deck (56):
What are the two requirements for topical ocular drugs?
Ability to act on the surface of the eye
Ability to penetrate the cornea
The epithelium of the cornea is hydrophilic and the stroma of the cornea is hydrophobic. T/F
Epithelium = hydrophobic/lipid loving
Stroma = lipophobic/water loving
Which type of drugs penetrate the corneal epithelium and stroma respectively?
Epithelium - lipid soluble
Stroma - water soluble
Which ocular antibiotic possesses both lipophilic and hydrophilic qualities?
What can alter the properties of the epithelium and in what way?
Inflammation can cause the epithelium to become more hydrophilic
What can alter the properties of the stroma and in what way?
The tear film can cause the epithelium to become more hydrophobic
How can topical steroids be altered to make them more 1) hydrophobic and 2) hydrophilic?
1 - alcohol/acetate
When does prednisolone acetate penetrate the cornea best?
When it is uninflamed
When is prednisolone acetate used?
When does prednisolone phosphate penetrate the cornea best?
When it is inflamed
When is prednisolone phosphate used?
In corneal disease or when low dose steroids are required
What chemical can alter the properties of the tear film? What else is it useful for?
Benzalkonium (makes it less hydrophobic). Also a preservative
Where can excess topical ocular drugs get systemically absorbed? How can this be halted?
Nasopharynx (via nasolacrimal duct). Punctal occlusion for five minutes
Other than topical, what are some routes of administration?
Subconjunctival, subtenons, intravetral, intracameral
Name some frequently used ocular antibiotics
Chloramphenicol, gentamicin, ofloxacin
Name an ocular antiviral
What are the types of anti-inflammatory agents used in the eyes?
Steroids, topical NSAIDs, anti-histamines and mast cell stabilisers
When are steroids used?
Post-op cataract surgery
Prevention of corneal graft rejection
What steroid is typically used in uveitis?
What are the local effects of steroids?
Cataract, glaucoma and exacerbation of viral infection
What are the systemic effects of steroids?
Osteoporosis, weight gain, gastric ulcers, immunosuppression
How is temporal arteritis treated?
List the strengths of topical steroids from weakest to strongest
Fluorometholone (FML) >
Predsol (prednisolone phosphate) >
When are anti histamines or mast cell stabilisers used?
Hayfever, allergic conjunctivitis
When might topical NSAIDs be used?
For pain e.g post laser surgery
What is glaucoma?
A group of diseases which bring about progressive and irreversible optic neuropathy (often with raised IOP) resulting in visual field defects
What is the only modifiable risk factor for glaucoma?
How does glaucoma typically present?
Who screens for glaucoma?
What is the relationship between glaucoma and age?
Glaucoma increases with age
What are the categories of glaucoma medication?
Carbonic anhydrase inhibitors
Alpha2 adrenergic agonist
Name a prostanoid medication
Name beta blockers used in glaucoma
Timolol, betaxolol, levobunolol, carteolol
Name a topic and systemic carbonic anhydrase inhibitor
Topical - dorzolamide
Systemic - acetazolamide
Name an alpha2 adrenergic agonist
Name a parasympathomimetric
Name a combination medication for glaucoma
dorzolamide and timolol (cosopt)
What are the side effects of alpha2 agonists?
What is the main side effect of parasympathomimetric?
Name three scenarios in which intra-vitreal injections are used
Antibiotic delivery in endopthalmitis
Anti-VEGF in wet macular degeneration
How does local anaesthetic work in the eye?
Blockage of sodium channels responsible for nerve conduction
List scenarios when local anaesthetic would be used
Foreign body removal
What is a side effect of local anaesthetic?
List scenarios where diagnostic dye would be used
Detecting corneal abrasions
Detecting nasolacrimal duct obstruction
What do mydriatic drugs do?
Dilate the pupil
How do mydriatic drugs work?
Block parasympathetic supply to the iris
What are the side effects of mydriatic drugs?
AACG (acute angle closure glaucoma)
What do sympanometrics do?
Dilate the pupil
How do sympanometric drugs work?
Act on the sympathetic nerves suppling the iris causing them to dilate
Do sympanometric drugs affect the accomodation reflex?
Name some sympanometric drugs
Name some mydriatic drugs
What is a side effect of the epilepsy medicine vigabatrin?
Constricted visual fields
What is a side effect of the TB drub ethambutol?
Optic nerve neuropathy
What is a side effect of the antimalarial/DMARD drug hydroxychloroquine?
Bullseye maculopathy when used long term