## Antibiotic Prophylaxis in Cataract Surgery ### Rationale for Ciprofloxacin **Key Point:** Fluoroquinolones (specifically ciprofloxacin and moxifloxacin) are the preferred topical antibiotics for perioperative prophylaxis in cataract surgery due to superior corneal penetration, broad-spectrum coverage, and excellent intraocular bioavailability. **High-Yield:** The 2023 AAO and ESCRS guidelines recommend topical fluoroquinolones as first-line prophylaxis. Ciprofloxacin 0.3% is widely available, cost-effective, and covers both gram-positive and gram-negative organisms responsible for post-operative endophthalmitis. ### Mechanism of Action - Inhibits bacterial DNA gyrase - Achieves high aqueous humor concentrations (>1 µg/mL after topical instillation) - Effective against *Staphylococcus aureus*, *Staphylococcus epidermidis*, *Pseudomonas aeruginosa*, and gram-negative rods ### Dosing Schedule | Timing | Regimen | |--------|----------| | Preoperative (day of surgery) | 4 times, 15 min apart, starting 15 min before surgery | | Intraoperative | Instilled at end of surgery | | Postoperative | 4 times daily × 3–4 weeks | **Clinical Pearl:** Moxifloxacin 0.5% is an alternative with slightly better gram-positive coverage, but ciprofloxacin remains the standard first-line choice globally due to cost and availability. ### Why Fluoroquinolones? - Superior aqueous penetration compared to aminoglycosides or macrolides - No risk of corneal toxicity (unlike aminoglycosides with prolonged use) - Broad-spectrum coverage without the toxicity profile of older agents [cite:AAO Cataract and IOL Surgery Guidelines 2023]
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