Opthamology Flashcards
What is the sclera, what is the uvea, what is the retina
Outermost layer of white fibrous tissue, Middle layer beneath the slcera, innermost layer of the eye
What are the parts of the uvea
iris (colored portion, melanin), ciliary body, pupil and choroid
What parts in the retina aid in transmitting information
Cones: provided color and central vision, rods: peripheral and nighttime vision
What is the fluid that most influences intraocular pressure, what produces it
Aqueous humor, ciliary body
T/F: The virteous humor is in constant flux but the aqueous humor is stagnant
False: The aqueous humor is in constant flux and the vitreous is stagnant
What parts of the eye allow for sight and at what proportions
Lens (1/3), Cornea (2/3)
What part of the is the gateway to the rest of the body that also keeps debri from getting to the back of the eye
Conjuctiva
What is myosis, mydriasis
Pupil constricts, pupil dialates
What causes cataract formations
Denaturing of proteins in the lens
Where do most medications become abosrbed, what are the layers
Cornea, Epitheleal (lipophilic), stroma (hydrophilic), endothelium (lipophilic)
T/F: Cornea is the only part of the eye that can be transplanted because it is avascular
True
What are the four type of injectable formulations for the eye
Intracameral, subconjunctival, sub-tenon’s, intravitreal
What are the barriers to drug delivery in the eye
Tear film, Cornea (tight junctions and layers), conjunctiva, choroid, blood-ocular barrier
How does the tear film effect drugs
Reduces/dilutes the effective concentration of the drug/drop, accelerates the clearance of the drug, lacrimal fluid reduces the binding efficiency of the drug to the cornea
What are the two portions of the blood-ocular barrier, characteristics of the barriers
Blood aqueous barrier:Physical barrier between local blood vessels;breakdown due to inflammation (restrengthens once inflammation ceases)
Blood retinal barrier: restricts drug transport from the choroid/blood into the retina; may be destroyed by diabetic nueropathy causing bleeding in the eye (DOESN’T HEAL)
What are the types of dilating eye drops
Mydriatics: stimulate contraction of the muscles that enlarge the pupil
Cycloplegics: relax the muscles that make the pupil constrict and that focus the lens of the eye
T/F: Darker colored eyes have longer duration for dilating eye drops
False: Light colored irises have longer effects from dilating eye drops
What are the dilating eye drops in order from shortest to longest duration
Tropicamide (6 hours), cyclopentolate, homatropine (1-3 days), atropine (At least one week)
What eye drop can be added to dilating eye drops for more dilation, when is it most effective
Phenylephrine, after the age of 60
What are the adverse effects of using dilating eye drops, who should be cautious when using these
blurry vision, photophobia, dry mouth and tachyarrythmia (if systemic)/ caution with narrow-angle glaucoma
What is the proper steps to use eye drops
1) Wash hands
2) Tilte head backward
3) Gently pull back lower lid
4) Let a drop fall into pocket formed
5) SLOWLY let go lower lid and close eye gently (DO NOT SHUT EYE)
6) Punctal occlusion
7) Blot around eye to remove excess moisture
Why must drops be seperated by a certain amount of time if there is supposed to be multiple drops, how long is the seperation
Allows for tear turnover and absorption to be complete, risk dilution of first drop/ five minutes
If someone is getting an ointment how long must the eye be shut for ample absorption
At least 1-2 minutes (GIVE at NIGHT/Sleeping)
T/F: Always use eye drops first, wait 5 minutes then apply ointment/gel
True
Where or why are the injections injected
PIntracameral: injection into the anterior chamber
Subconjunctival: used to give prolonged administration or increased penetration of the drug
Sub-Tenon’s: used to treat inflammation of the posterior segment
Intravitreal: injected into the vitreous
T/F: Increased pH allows for more lipid penetration
True
What is the preservative that causes allergic reactions and irritation but also increases absorption
Benzalkonium
What is glaucoma
A progressive disease that leads to an optic neuropahty characterized by ocular hypertension, damage to the optic nerve and peripheral vision loss
What are the types of glaucoma
Open angle, angle closure, and congenital
What is a normal IOP
between 10 and 20 mmHg
How does the aqueous humor leave the anterior chamber
Trabecular meshwork (85%), ciliary body and suprachoroidal space
