Abstract
Purpose:
To investigate the safety and a half-life of 0.1% and 0.3% of intravitreal povidone-iodine (PVI) and the efficacy of 0.1% PVI repeated injection and 0.3% PVI single injection in experimental S. epidermidis endophthalmitis
Methods:
In Phase I study, the pharmacokinetics and the safety of PVI were investigated. Forty New Zealand White rabbits were divided into two groups as 0.1 % and 0.3% PVI group. After 0.1% and 0.3 % PVI were injected into vitreous cavity, the pharmacokinetics of PVI was analyzed using high performance liquid chromatography (HPLC). To confirm the safety of 0.1% and 0.3 % PVI, electroretinography (ERG) and histologic examination were conducted at baseline, 6 hours and 12 hours after PVI injection.<br /> In Phase II study, the efficacy of PVI for S. epidermidis endophthalmitis was evaluated in 3 groups (n=10 in each group). After the induction of S. epidermidis endophthalmitis, 0.1% PVI was injected three times every second day in Group A and 0.3% PVI once in Group B. Group C as control did not receive PVI injection. Slit lamp and fundus examination were performed every other day for 2 weeks. ERG, histologic examination and vitreous culture for S. epidermidis were conducted at day 14.
Results:
In Phase I, ERG and histologic findings did not show notable retinal damage in both 0.1% and 0.3% PVI groups and Half-Life in vitro was 3.27 and 3.58 hours, respectively. In Phase II, Group A and B showed a significant improvement of endophthalmitis compared to Group C. All of 10 eyes showed no growth of S. epidermidis in vitreous of Group A at day 14. Of 10 eyes in Group B, 3 eyes demonstrated a bacterial growth (20, 40 and 60 CFU) in vitreous. In both groups, mild to moderate retinal damage was detected as lymphocyte infiltration in retina histology.
Conclusions:
Intravitreal 0.1% and 0.3% of PVI were tolerated in rabbit eyes. Repeated injection of low concentration PVI was likely to be more effective for the treatment of S. epidermidis endophthalmitis, compared to single injection of high concentration PVI. Further study is needed for various micro-organisms.