Drugs used to tx stromal abscesses must be able to do what?

• A. Penetrate epithelium
• B. Cross blood-brain barrier
• C. Be bacteriostatic
• D. Be colorless

Answer: (A)

Drugs for a stromal corneal abscess must be able to penetrate the corneal epithelium to reach the infection within the stroma. The epithelium forms a barrier; if a topical antibiotic can’t cross it, it won’t achieve therapeutic levels where the bacteria are located. So, the key requirement is sufficient epithelial penetration (followed by diffusion through the stroma) to treat the abscess effectively.

Crossing the blood-brain barrier isn’t relevant to the eye, since this infection is local to the cornea and topical delivery is used. Whether a drug is bacteriostatic or bactericidal is important for overall efficacy, but it won’t matter if the drug never gets to the bacteria in the stroma. Being colorless has no bearing on treating a stromal abscess.