Drops with Liposomal Ozonized Oil Reduce Ocular Microbial Burden Before Cataract Surgery

Anti-inflammatory Ozone

Ozone in both gaseous and aqueous phases represents a strong and reliable antimicrobial agent with antiseptic and anti-inflammatory effects. It is capable of destroying all known types of gram-positive and gram-negative bacteria, including extremely resistant bacteria, such as Escherichia coli and multi-resistant Staphylococcus aureus. Gaseous ozone is an unstable molecule composed of 3 oxygen atoms, but it can be stabilized in the form of a liposomal ozone dispersion. A specific formulation for ocular use, consisting of 0.5% ozonized oil in liposomes with the addition of hypromellose, was recently introduced to the market. 

Methodology and Course of the Study

A prospective interventional multicenter non-randomized phase IV clinical study used the second non-operated eye of each patient as a control. The study population consisted of 174 patients aged > 18 years who underwent cataract surgery from June 2019 to December 2020 in one of the 20 participating centers. 

Patients applied 2 drops of the investigated isotonic ocular solution (0.5% ozonized liposomal sunflower oil with hypromellose) 4 times a day to the eye scheduled for surgery for 3 days before the planned operation, while the second eye was treated with saline solution.  

Subconjunctival swabs were taken from each eye before the start of treatment (i.e., 4 days before surgery) and then 10 minutes before the procedure. All collected samples were sent for analysis to the microbiology department of the University Hospital in Turin within 24 hours. 

Results

30% of the 696 swabs taken before the application of eye drops were sterile. Contaminated swabs had a high prevalence of coagulase-negative staphylococci, including Staphylococcus epidermidis. More than 60 different bacterial species were isolated. Following the administration of drops with liposomal ozonized oil, there was a significant reduction in microbial burden in > 90% of samples. The microbial burden in the control group remained unchanged.

Only 3 (1.7%) of the 174 patients reported an ocular adverse event in the treated eye, which was minimal conjunctival hyperemia. No other signs of conjunctival involvement (discharge and papillae) were noted in any of the patients. 96.0% did not experience any ocular discomfort during the use of the drops, mild discomfort occurred in 6 patients (3.5%). No corneal abnormalities or other significant side effects were observed. None of the patients showed signs of endophthalmitis after cataract surgery.

Conclusion

Local treatment with liposomal ozonized oil in the studied population significantly reduced ocular microbial burden without toxicity or allergenic activity. Therefore, it could be considered a safe and effective adjuvant in preoperative and home prophylaxis for patients undergoing cataract surgery.

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Source: Spadea L., Zanotto E., Cavallo R. et al.; ELOOM Study Investigators. Effectiveness of liposomal ozonized oil in reducing ocular microbial flora in patients undergoing cataract surgery. J. Cataract Refract. Surg. 2021; 47 (12): 1548−1555, doi: 10.1097/j.jcrs.0000000000000672.