Liposomal Ozonated Oil Ensures a Further Reduction in the Microbial Load Before Intravitreal Injection: the "OPERA" Study

Introduction: This was a prospective study to investigate the antimicrobial efficacy of a novel ophthalmic solution comprising ozonated sunflower oil in liposomes plus hypromellose in conjunction with liposomal foam (BlefOX), in patients undergoing intravitreal injection, in comparison to povidone iodine 5%. Methods: The study employed a paired-eye design with n = 195 patients and a total of n = 390 eyes divided into two groups. Conjunctival swabs were collected from both eyes of each patient at baseline (T0-3 days before the injection). The study group underwent home therapy, which included instilling two drops of an isotonic ophthalmic solution containing 0.5% ozonated sunflower oil in liposomes plus hypromellose (Ozodrop) four times daily and applying liposomal foam twice daily to the eye undergoing intravitreal injections. In contrast, the control group (contralateral eyes) received treatment with povidone iodine 5%. This treatment regimen was maintained for 3 days. At T1 (10 min before injection), all patients instilled one drop of a topical solution of povidone iodine 5% into the conjunctival sac of both eyes. After 30 seconds had elapsed, a conjunctival swab was obtained for each eye in both study groups. Results: The results, derived from conjunctival swabs, exhibited a significant reduction in the microbial load of the study group on both chocolate agar and blood agar (p <= 0.007). The study demonstrated that the combination of povidone iodine 5% + Ozodrop + BlefOX provides a greater reduction in microbial load than povidone iodine 5% alone on both chocolate agar (141 [72.31%] vs. 98 [50.26%], p < 0.0001) and blood agar (130 [66.67%] vs. 97 [49.74%], p = 0.0007). The combination of povidone iodine 5% + Ozodrop + BlefOX resulted in the killing of approximately 41% to 49% of bacteria compared to povidone iodine 5% alone on the chocolate agar and blood agar, respectively. Conclusions: Liposomal ozonated oil treatment, coupled with liposomal foam, in patients undergoing intravitreal injection led to a substantial reduction in conjunctival microbial load compared to eyes treated solely with povidone iodine 5%.