A 3-Year Monitoring Of Postoperative Infectious Incidence After Cataract Surgery And Intravitreal Injections With Adjunctive Liposomal Ozonated Oil: Results From The Pro.Prio Multicenter Study

Postoperative endophthalmitis (POE) remains a rare but potentially vision-threatening complication of cataract surgery and intravitreal injections (IVI), with reported incidence rates of 0.02–0.05%. POE generally occurs within 1-2 weeks, often 3-5 days after surgery or IVI (acute endophthalmitis). Despite standardized antiseptic protocols and advances in surgical techniques, POE continues to represent a measurable adverse outcome in routine practice. The PRO.PRIO study was designed to assess the incidence of postoperative infectious complications and local tolerability in a large real-world cohort receiving adjunctive liposomal ozonated oil ophthalmic support in addition to standard prophylaxis.

This prospective, multicenter, real-world observational study (PRO.PRIO) was conducted across 25 Italian ophthalmology centers between 2023 and 2025.

Consecutive adult patients undergoing cataract surgery or IVI were included. All procedures followed standard perioperative prophylaxis, including 5% povidone-iodine antisepsis and intracameral cefuroxime for cataract surgery. As adjunctive support, a liposomal ozonated oil ophthalmic solution was administered for 3 days preoperatively (1–2 drops, four times daily). Patients were followed for 30 days to detect suspected or confirmed postoperative infectious complications. Local tolerability was assessed preoperatively using standardized grading scales for ocular signs and symptoms. Absolute frequencies and percentages were calculated using the PROC FREQ procedure in SAS v. 9.4.

A total of 63,429 intraocular procedures (39,164 cataract; 24,265 IVI) were followed for 30 days. Two postoperative infections occurred corresponding to an incidence of 0.003% (3/100,000), markedly lower than contemporary epidemiological benchmarks (0.02–0.05%). Complications were graded on a five-level severity scale (0–4). Grade 0 findings exceeded 85% in both groups. Absence of signs and symptoms (cataract vs IVI) was: conjunctival hyperemia (85.1% vs 86.4%); secretion (97.1% vs 99.0%); papillae (97.0% vs 99.7%); conjunctival alterations (99.2% vs 99.2%); burning (86.0% vs 86.0%); foreign body sensation (88.9% vs 91.5%). The Visual Analogue Scale (VAS) showed excellent tolerability of liposomal ozonated oil (96.8% cataract; 95.6% IVI).

In this large national multicenter real-world cohort, adjunctive peri-procedural use of liposomal ozonated oil ophthalmic solution was associated with a low incidence of postoperative infectious complications and good local tolerability. Although causal inference cannot be established in the absence of a control group, these findings support further controlled investigations to better define the role of ocular surface optimization strategies in reducing infectious risk after intraocular procedures.