Eye general info Flashcards
How do you administer eye drops?
- Wash your hands
- Tilt your head back
- Gently pull down palpebra conjunctiva to form a pocket
- Hold the dropper above the eye
- Look up
- Squeeze a drop into the pocket w/o touching the eye
- Close the eye for 1-2 mins
How long do topical solutions stay in the eye?
15-30 mins
Name dosage forms that are administered topically
drops, ointment, gels, inserts
Name the dosage forms that are administered systemicly
IV, oral, IM
What are the anterior routes of delivery in the eye?
Anterior: punctal, subconjunctival, topical, intrascleral, fornix
What are the routes of delivery for the middle and posterior regions of the eye?
Middle: intravitreal
Posterior: subretinal, suprachorodial, anterior and posterior sub-Tenon’s
All drugs administered in the eye must be ______
Sterile
Name two characteristics of an ideal ocular drug
- Long residence time
- Causes no irriation
What are some of the special pharmacokinetics of the eye?
Sequestered Low blood supply compared with other regions Easily accessible
What are some of the special pharmacodynamics of the eye?
Poor absorption rate Localized action High metabolism and excretion of drug Drugs absorption in the eye experience first pass after causing effect
Ocular Dosage Forms
- Drops in solution
- Drops in suspension
- Injection
- Ointment
- Insert
- Gel
What are the 9 classes of Ocular drugs?
- Antibacterial (antibiotics)
- Antivirals/Antifungals
- Mydratics and cycloplegic
- Antiglaucoma
- Anti-inflammatory agents (Corticosteroids and NSAIDS)
- Ocular Lubricants
- Ocular Diagnostic Drugs
- Local anesthetics
- Cannabinoids
What are the benefits of Ocular ointments
- Increase residence time
- Usually mineral oil/petrolatum base, which moisten the eye
What are the disadvantages of Ocular ointments
Cause blurred vision
Dosing imprecise
Difficult for patients to apply
What are the advantages periocular injections?
Better than topical for reaching behind iris or lens (E.g. subconjunctival, subtenon, peribulbar, or retrobulbar) Bypasses conjunctival and corneal epithelium good for drugs with low lipid solubility (e.g. penicillins)
Describe what happens during miosis.
- M3 and M2 muscarinic receptors bind acetylcholine
- Iris sphincter contraction
- Ciliary muscles contract
What happens during Mydriasis?
- Alpha 1 receptors bind epinephrine/ norepinephrine on Iris radical muscles which contract
- Beta 1 ciliary muscles relax for far vision
What happens in wet Macular degeneration?
Vascular Endothelial Growth Factor (VEGF) stimulates vascular endothelial cell growth and new vascular structures are formed. This vessels begin to leak fluid or blood into the macula which effect vision.
