Cataract Surgery by Intraoperative Surface Irrigation with 0.25% Povidone–Iodine

Abstract

Postoperative endophthalmitis after cataract surgery is typically caused by the patient’s own conjunctival normal bacterial flora. A three-step approach is recommended to prevent endophthalmitis: (1) “border control” to prevent microorganisms from entering the eye by disinfecting the ocular surface is the most important measure; (2) bacteria that have gained access into the anterior chamber are reduced by irrigation; (3) bacteria remaining in the anterior chamber and vitreous at the end of surgery are controlled by antibacterial drugs. We have devised a method, “the Shimada technique”, for irrigating the ocular surface with povidone-iodine, a disinfectant with potent microbicidal effect and established effective and safe concentrations for eye tissues. Povidone-iodine exhibits a bactericidal effect for a wide concentration range of 0.005–10%, but 0.1% povidone-iodine has the highest activity and requires the shortest time of only 15 s to achieve microbicidal effect. When used to irrigate the ocular surface every 20–30 s during cataract surgery, 0.25% povidone-iodine is conceivably diluted to around 0.1%. Irrigation with 0.25% povidone-iodine during cataract surgery significantly reduced bacteria contamination rate in the anterior chamber compared with saline (p = 0.0017) without causing corneal endothelial damage.

Safety Measures for Maintaining Low Endophthalmitis Rate after Intravitreal Anti-Vascular Endothelial Growth Factor Injection before and during the COVID-19 Pandemic

“…We believe that povidone-iodine is the most important measure for preventing endophthalmitis after intravitreal injection. When using povidone-iodine, it is important to understand the optimal concentration used, the contact time required, and the amount and frequency of application [32][33][34].…”

“…We have been using 0.25% povidone-iodine [8,28]. Povidone-iodine is inactivated when it acts on bacteria, and 0.25% povidone-iodine with a low iodine content does not remain effective for long after a single irrigation [32,33]. Hence, we irrigate the ocular surface twice before injection to maintain the disinfection effect.…”

The eye wash technique: A simple and effective technique for intraoperative ocular surface lavage

“…Most cases of cataract surgery post-operative endophthalmitis are caused by bacteria from the patient's own conjunctival and periocular flora. [8][9][10][11] Bacteria were detected in the surgical drape fluid catch bag in a significant proportion of patients when the eye was irrigated with saline, [12] showing their permanence in the ocular surface during surgery. Bacteria from the conjunctival and periocular flora routinely gain access to the anterior chamber and are still present at the end of a significant proportion of surgeries.…”

Possibility of surgical field contamination by the patient’s exhaled air: evaluation using a carbon dioxide imaging camera and particle counter

“…While the procedure for vitreous injections is completed quickly, endophthalmic surgery takes a much longer time, and there is a risk of ocular surface contamination during the procedure, even if the ocular surface was properly disinfected before the start of surgery. For this reason, methods, such as iodine disinfection, performed not only before the start of surgery but also during procedures with a high risk of bacterial stray, such as during lens insertion, and the application of iodine intermittently during surgery have been reported [21][22][23] .…”