Occular Pharmacology Flashcards
what are the properties of the epithelium of the cornea?
lipophilic and hydrophobic
what are the properties of the stroma of the cornea?
lipophobic and hydrophilic
what layer of the cornea do lipid soluble drugs penetrate?
the epithelium
what layer of the cornea do water soluble drugs penetrate?
the stroma
why is Chloramphenicol particularly good at penetrating the cornea?
it has lipophilic and hydrophilic properties
what can reduce the hydrophobic nature of the endothelium of the cornea?
ocular surface inflammation
what type of drugs does the epithelium of the cornea limit?
hydrophilic drugs
what type of drugs does the stroma of the cornea limit?
hydrophobic drugs
what affect does adding alcohol or acetate to a steroid have?
makes it more hydrophobic
what affect does adding phosphate to a topical steroid have?
makes it more hydrophilic
does prednisolone acetate have a good or bad penetration in an uninflamed cornea?
good penetration
when is prednisolone acetate most often used?
post-operatively
does prednisolone phosphate have a good or poor penentration in an uninflamed cornea?
poor
what is prednisolone phosphate used for?
for cornea disease or when u want low dose steroid
why is benzalkonium added to eye treatment bottles?
it is a preservative
other than being a preservative, what else does benzalkonium do?
disrupts lipid layer of tear film- therefore aids penetration of some drugs
how long do bottles of eye treatment last before they are no longer effective?
about 4 weeks
how can eye drops be systemically absorbed and where does this happen?
tears are pumped out of lacrimal sac rapidly and excess goes to systemic absorption in the nasopharynx
what are the 4 types of injections?
subconjuctival and subtenons. Intravitreal and intracameral