Comparative Efficacy of Different Regimens of PVPI 5% Eye Drops Instillation in Reducing Conjunctival Bacterial Flora

Comparative Efficacy of Different Regimens of PVPI 5% Eye Drops Instillation in Reducing Conjunctival Bacterial Flora

Comparative Efficacy of Two Different Regimens of Povidone-iodine 5% Eye Drops Instillation in Reducing Conjunctival Bacterial Flora

The present study intends to assess the efficacy of 3 drops of 5% povidone-iodine (PVPI) eyedrops in reducing the bacterial flora in a conjunctival sac fundus compared to the standard procedure consisting of the application of 1 PVPI eyedrop 2 min before any intraocular surgical procedure.

Studies have demonstrated that the external bacterial flora of the patients in most cases is the actual source of infection. The objective of antisepsis is to eliminate or significantly reduce the number of microorganisms in the surgical field at the time of surgery. The eyelids and the conjunctiva are considered to be quite common sources of bacteria that can lead to endophthalmitis. Thus, it is believed that by reducing the number and growth of bacteria on the ocular surface and adnexa before surgery, the risk of postoperative infection would be lower. Povidone-iodine 5% eye drops has been used in preoperative cataract surgery to prevent endophthalmitis and is the standard prophylactic action in preventing postoperative endophthalmitis being widely compared with other antibiotic eye drops and their associations. The standard procedure of prophylaxis of postoperative endophthalmitis corresponds to applying a single drop of povidone-iodine 2min before any intraocular surgical procedure. However, few studies have assessed the effectiveness of povidone-iodine 5% eye drops using different dosing regimens to achieve the best bactericidal effect. The aim of this study is to investigate different dosages with respect to the use of povidone-iodine drops to optimize the effectiveness of the agent, ensuring the best exogenous endophthalmitis prophylaxis.

1 drop of saline solution 0.9% will be instilled at time zero and 20-minute. At 28-minute will be instilled 1 drop of Povidone-iodine 5%.

Conjunctival swab will be obtained five minutes before and 30 minutes after the first povidone iodine drop will be instilled into the conjunctival sac of study eye. Conjunctival swabs were incubated aerobically in enriched Thioglycolate liquid medium (meat broth) and in three solid culture media (Agar Chocolate, Trypticase Soy Agar with 5% sheep blood, and Agar Sabouraud).

Corneal paquimetry will be performed before and after procedure using OcuScan Alcon RXP (Alcon, Fortworth, Texas).

Inclusion Criteria: No systemic or ocular infection; Absence of auto-imune disease or immunosuppressive therapy; No use of systemic or topic antibiotics in the last 30 days; No previous ocular surgery or trauma in the study eye in the last 30 days; No history of allergy to povidone iodine; Signed informed consent. Exclusion Criteria: Presence of blepharitis, ectropion, entropion, trichiasis or distichiasis; Diabetes Mellitus; Any systemic condition that, at the discretion of the investigators, would facilitate or contribute to infection, such as influenza; Inability to understand and sign the informed consent.