Pharmacology Flashcards
Describe the layers of the cornea in terms of lipophilic/hydrophilic
Outer layer (epithelium) is lipophilic
Intermediate (stroma) layer is hydrophilic
Inner layer is lipophilic
Ocular surface inflammation can increase/decrease the lipophilic nature of the endothelium
Decrease
Acetate makes steroid more hydrophobic/philic while phosphate makes steroid more hydrophobic/philic
Acetate makes steroid more hydrophobic while phosphate makes it more hydrophilic
Prednisolone acetate has good/poor penetration in an uninflamed cornea
Good
When is prednisolone phosphate used?
Corneal disease
Want low dose steroids
What chemical is used as a preservative and helps in the penetration of some drugs?
Benzalkonium
How can a patient reduce systemic absorption of topical drugs?
By pinching their nose for 5 minutes
When are steroids used in eye disease?
Post-op cataracts
Uveitis
Prevent corneal graft rejection
Give some ophthalmic side effects of steroids
Cataract
Glaucoma
Exacerbation of viral infection
What is glaucoma?
Progressive damage to CN II causing peripheral field loss
What is the only modifiable risk factor for glaucoma?
Intra-ocular pressure
How do glaucoma drops work?
Stop ciliary body producing aqueous
Opening canal of Schlemm
Give examples of glaucoma medication
Latanoprost
Beta blockers
Carbonic anhydrase inhibitors
Alpha agonists
When are intravitreal injections used?
Administrating antibiotics in endophthalmitis
Intra-ocular steroids
Anti-VEGF
How is macular degeneration treated?
Anti-VEGF
How does local anaesthetic in the eye work?
By blocking Na channels
Give some uses of fluorescein
Corneal abrasion
Angiography
Nasolacrimal duct obstruction
What test shows if aqueous humour is leaking?
Seidel’s test
How do mydriatic drugs work?
Block parasympathetic supply to sphincter pupillae causing dilation
Give examples of mydriatic drugs
Tropicamide
Cyclopentolate
How do sympathomimetics work?
Act on sympathetic system to increase action of iris dilator
Give examples of sympathomimetics
Phenylephrine
Atropine
Which drug is most commonly used to dilate the pupil?
Tropicamide
Which tuberculosis drug can cause irreversible optic neuropathy?
Ethambutol
Which DMARD can cause maculopathy?
Hydroxychloroquine
