Pharmacology Flashcards
Epithelium of cornea is lipophilic/phobic
Stroma is ??
Cornea is a --_ sandwich
Makes drug penetration difficult
Epithelium = lipophilic
Stroma = lipophobic
Lipid water lipid
Corneal penetration is easy for ___ drugs
LMW
Chloramphenicol has __+__ properties and so easily penetrates the cornea
Lipophilic and phobic
Ocular surface inflam can ___ the hydrophobic nature of the corneal epithelium
Decrease
___/___ can be added to steroids that are topically applied to the eye to make them more hydrophobic
Alcohol
Acetate
___ is added to eye topical steroids to make them more hydrophilic
Phosphate
Prednisolone acetate topical is hydro___, used ___, ___ penetration in uninflamed cornea
Phobic
Post op
Good
Prednisolone phosphate is hydro___, used for ___/___, ___ penetration in uninflamed cornea
Philic
Cornea disease/low dose steroid needed
Poor
___ is used to enhance penetration of topical eye Rx because it disrupts the lipid layer of the tear film
Eg = used to lower IOP in glaucoma
Benzalkonium
Bimatoprost 0.01%
Can limit systemic absorption of topical eye drugs through the lacrimal duct by ___
Punctal occlusion
Subconjunctival delivery of drugs are deposited ___
For : (4 egs)
To anterior and posterior segment Glaucoma CMV retinitis AMD PU
Subtenons injection location =
For (4 egs)
Between capsule and sclera DME AMD RVO PU
Intravitreal drugs (3)
Steroids
Anti VEGF
Antibiotics for endophthalmitis
Intracameral injection site -
Purpose
Anterior chamber
Anaesthetics
Drugs used for inflam in eye disease
Steroid
Topical NSAIDs
Antihistamines
Mast cell stabilisers
Topical steroid indications in eye disease
Post op cataracts
Uveitis
Prevent corneal graft rejection
Used in hayfever/allergic conjunctivitis
Antihistamines and mast cellstabilisers
Local side effects of steroids in the eye
Cataract
Glaucoma
Exacerbates viral infection
When are topical NSAIDs used in the. Eye
For pain relief eg post refractive laser
Glaucoma are a group of diseases characterised by _____ leading to ____
A progressive optic neuropathy
Visual field defects
Rx of glaucoma 1st line =
Prostanoids - latanoprost (xanatan)
Rx for glaucoma options
Prostanoids (1st) eg latanoprost Beta blocker eg timolol, betaxolol Carbonic anhydrase inhibitors eg topical dorzolamide, PO acetazolamide Alpha2 agonist eg brimonidine Parasympathometic - pilocarpine Combo of dorzolamide and timolol
LA method of action in the eye =
Indications
Block Na channels and impede nerve conduction Fb removal Tonometry Corneal scrape To examine
Fluorescein Ix indications
Corneal abrasion
Tonometry
Nasolacrimal duct obstruction
Angiography
Mydriatics examples
Tropicamide
Cyclopentolate
How do mydriatics do what they do?
Block parasymps to iris and so pupil dilates
Rare side effect of mydriatics
To safety net tell ptnt to
Acute closed angle glaucoma
Come back if thumping headache/doesnt wear off
Effect of sympathomimetics
Examples
Enhance symp to iris to make pupil dilate (doesnt affect ciliary muscle so accomodation is ok)
Lasts longer than mydriatic
Phenylephrine, atropine
Vibagatran Side effect on the eye
Constrict visual fields
Ethambutol side effect on the eye
Optic neuropathy
Chloroquine. Side effect on the eye
Maculopathy (screen for this if on it more than 5yrs)
Yellow pigment line across cornea is caused by what drug
Amiodarone
