What is the recommended protocol for ocular disinfection before ophthalmic surgery?

Ocular Disinfection Protocol Before Ophthalmic Surgery

Apply 5-10% povidone-iodine to the periocular region (lids, brow, cheek) and 5% povidone-iodine solution directly onto the ocular surface (cornea, conjunctiva, palpebral fornices), followed by thorough irrigation with sterile saline before beginning surgery. 1, 2

Preoperative Antiseptic Application

Povidone-Iodine Protocol (Gold Standard)

• Apply 5-10% povidone-iodine to the periocular skin for at least 3 minutes before surgery 1, 3
• Instill 5% povidone-iodine solution directly onto the ocular surface, ensuring contact with the cornea, conjunctiva, and palpebral fornices 1, 2
• Allow the solution to remain for at least 3 minutes to achieve optimal microbicidal effect, as 0.1% concentration (achieved through dilution) requires only 15 seconds but higher concentrations ensure adequate coverage 4, 3
• Flush the eye thoroughly with sterile saline solution after povidone-iodine application to prevent corneal toxicity 2

The FDA-approved Betadine 5% Sterile Ophthalmic Prep Solution is specifically indicated for this purpose and must be flushed thoroughly after each use 2. This approach provides the strongest evidence for reducing postoperative endophthalmitis risk 5.

Optional Adjunctive Antibiotic Pretreatment

• Consider prescribing topical broad-spectrum antibiotics for 3 days before surgery (such as 0.5% levofloxacin), though evidence is less compelling than for povidone-iodine 6, 7
• The 3-day antibiotic regimen shows significantly higher disinfection rates compared to 1-day or 1-hour applications (P<0.05) 7
• Note that complete bacterial elimination is difficult even with combined antibiotic and antiseptic use, as new isolates (mainly Propionibacterium acnes and Staphylococcus epidermidis) can emerge after treatment 7

Intraoperative Surface Irrigation

• Consider irrigating the ocular surface with 0.25% povidone-iodine every 20-30 seconds during surgery (the "Shimada technique"), which significantly reduces anterior chamber bacterial contamination compared to saline (p=0.0017) without causing corneal endothelial damage 4
• This concentration dilutes to approximately 0.1% upon contact, providing optimal bactericidal activity 4

Surgical Preparation Steps

Hand Hygiene and Sterile Technique

• Perform surgical hand antisepsis using antimicrobial soap and water, or soap and water followed by alcohol-based surgical hand-scrub with persistent activity before donning sterile gloves 8
• Ensure fingernails are short with smooth, filed edges; do not wear artificial fingernails or extenders 8
• Remove all hand and nail jewelry that compromises glove fit 8

Personal Protective Equipment

• Wear surgical mask and eye protection to prevent contamination 8
• Don sterile surgical gown covering personal clothing and skin 8
• Wear sterile surgical gloves after hand antisepsis 8

Instrument and Equipment Sterilization

• Ensure strict sterilization of all surgical instruments before use 1
• Carefully examine and clean the operative eye before applying disinfectant to remove any debris or discharge 1
• Avoid residual disinfectant contamination on instruments, as this can cause iatrogenic corneal damage 8

Additional Prophylactic Measures

• Consider periocular administration or intracameral injection of antibiotics (such as cefuroxime or moxifloxacin) immediately before the end of surgery 1
• Use viscosurgical devices during surgery to protect ocular tissues 1
• Minimize thermal energy from phacoemulsification devices and avoid large corneal incisions 1

Critical Contraindications and Precautions

• Do not use povidone-iodine on patients with known iodine sensitivity; consider chlorhexidine as an alternative antiseptic in these cases 2, 3
• Never use povidone-iodine for intraocular injection or irrigation—it is for external use only 2
• Ensure thorough saline irrigation after povidone-iodine application to prevent corneal epithelial toxicity 2, 4
• Discard multiple-dose eyedrop containers after any contact with the ocular surface to prevent cross-contamination 8

Common Pitfalls to Avoid

The most critical error is inadequate contact time with povidone-iodine—rushing through the 3-minute application period significantly reduces efficacy 3. Another common mistake is failing to irrigate thoroughly after povidone-iodine application, which can cause corneal de-epithelialization 8. Finally, relying solely on topical antibiotics without povidone-iodine is insufficient, as the evidence for antibiotics alone is not compelling 5.