Ocular Pharmacology and Therapeutics Flashcards

Which topical corticosteroid has the lowest tendency to raise IOP because of its ester-based design?

Answer: Loteprednol etabonate

Loteprednol is a retrometabolically designed ester steroid that is quickly inactivated, so it raises IOP less often.

Corneal melts were most notably reported with which topical NSAID formulation?

Answer: Generic diclofenac sodium

A generic diclofenac formulation was associated with clusters of corneal melting and was withdrawn from the US market in 1999.

Moxifloxacin exerts its antibacterial effect by inhibiting which target?

Answer: DNA gyrase and topoisomerase IV

Fluoroquinolones inhibit bacterial DNA gyrase and topoisomerase IV, which blocks DNA replication.

Which topical regimen is first-line for Acanthamoeba keratitis?

Answer: Biguanides such as PHMB or chlorhexidine

Biguanides like PHMB and chlorhexidine are active against both trophozoites and cysts, often combined with a diamidine such as propamidine.

According to MUTT I, which topical agent gave better outcomes for filamentous fungal keratitis, especially Fusarium?

Answer: Natamycin 5%

MUTT I found natamycin superior to voriconazole for filamentous fungal ulcers, mainly because of better outcomes in Fusarium cases.

In SCUT, adjunctive topical corticosteroids were associated with worse outcomes in ulcers caused by which organism?

Answer: Nocardia

SCUT subgroup analysis showed larger scars in Nocardia ulcers treated with steroids.

Besides its antibacterial action, oral doxycycline helps meibomian gland dysfunction mainly through which mechanism?

Answer: Inhibition of matrix metalloproteinases and bacterial lipases

Subantimicrobial tetracyclines inhibit MMPs and bacterial lipases, which reduces free fatty acids and ocular surface inflammation.