Basic concepts of ophthalmic antibiotics used in ophthalmology and classification criteria for antibacterial effects by strain

👁 Introduction to Ophthalmic Antibiotic Eye Drops – Classification & Spectrum of Action

Even in a healthy body, normal flora exist throughout the digestive tract, skin, and even around the eyes.
In ophthalmology, topical antibiotics are the primary treatment for bacterial infections and prevention in surgical settings.

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✅ Routes of Antibiotic Administration

• Systemic (IV or oral)
• Topical (eye drops or ointments)
• Subconjunctival, intracameral, intravitreal injections
  → Topical drops are most commonly used for external eye infections.

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✅ Common Bacterial Pathogens

InfectionMajor Pathogens

Keratitis / Corneal ulcer	S. aureus, Pneumococcus, Pseudomonas
Conjunctivitis	S. aureus, Pneumococcus, H. influenzae
Endophthalmitis	S. epidermidis, S. aureus, Pneumococcus

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✅ Antibiotic Classification Criteria

1. By Bacterial Spectrum
   • Anti-Staphylococcal
   • Anti-Pneumococcal
   • Anti-Pseudomonal
2. By Gram Staining
   • Gram-positive (purple) vs Gram-negative (red)
     → Influences choice of antibiotic

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✅ Key Antibiotic Classes in Ophthalmology

ClassPrimary Use

Quinolones	Broad-spectrum, first-line
Aminoglycosides	Effective against Pseudomonas
Tetracyclines	Oral use in lid/gland inflammation
Macrolides	Pediatric/infant-friendly alternative

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✅ What’s Next?

Each class will be discussed in detail with:

• Mechanism of action
• Trade names in Korea
• Dosage forms and usage tips
• Side effects and contraindications