Antibiotic injection cuts endophthalmitis risk after cataract surgery

Bayesian meta-analysis of 54 studies encompassing 6,867,422 cataract surgeries found intraoperative antibiotic injection reduced the risk of postoperative endophthalmitis compared with standard eye drop regimens, according to the study authors.¹ The analysis included 3,501,802 surgeries in which patients received antibiotic injection therapy, administered intracamerally or subconjunctivally.¹ Antibiotic injection was associated with an odds ratio of 0.208 (95% CrI, 0.161-0.268) for postoperative endophthalmitis, with a 100% posterior probability of clinically meaningful benefit.¹

The findings add quantitative support to the dropless cataract surgery approach, which administers antibiotics and corticosteroids intraoperatively rather than through a postoperative topical regimen. Traditional postoperative care for cataract surgery, the most performed surgical procedure worldwide with over 28 million cases annually, relies on topical eye drops for infection prevention and inflammation control. Patient noncompliance and cost limitations associated with topical regimens have driven interest in intraoperative alternatives.¹

These challenges have prompted evaluation of intraoperative alternatives combining antibiotic and corticosteroid administration at the time of surgery.¹ "The clinical significance of this finding, an approximately 5-fold reduction in postoperative endophthalmitis risk with intracameral as compared to topical antibiotics, cannot be overstated. Given the importance of preventing endophthalmitis, a severe complication of cataract surgery which often leads to permanent visual impairment, it is important for all cataract surgeons to incorporate this treatment in their surgical plan," C. Ellis Wisely, MD, MBA, associate professor of ophthalmology at the Duke Eye Center, told Ophthalmology Times.

The results add to a growing body of evidence examining strategies to streamline postoperative care after cataract surgery. The analysis was designed to evaluate the risk of postoperative endophthalmitis associated with antibiotic injection compared with the standard eye drop regimen used after cataract surgery.¹

What was the methodology and study design?

Investigators systematically searched PubMed, Embase, and the Cochrane Library for studies evaluating the safety of antibiotic injection during cataract surgery compared with conventional postoperative regimens.¹ The team applied a Bayesian random-effects meta-analysis to generate marginal posterior distributions for the overall treatment effect and between-study heterogeneity, expressed as odds ratios with 95% credible intervals. The investigators assessed study quality using validated bias-assessment tools suited to each study design, ROBINS-I for nonrandomized studies and RoB-2 for randomized studies.¹

The pooled model estimated a 99.1% likelihood future studies would confirm the reduction in endophthalmitis risk associated with antibiotic injection.¹ Sensitivity analyses performed across the dataset corroborated the primary finding, supporting the robustness of the observed benefit.¹ These results reflect data pooled across large real-world and randomized cohorts rather than a single clinical trial, reinforcing the consistency of the association across diverse surgical settings.

Antibiotic injection safety data and study limitations

The available summary does not report additional secondary endpoints, such as rates of toxic anterior segment syndrome, macular toxicity, or other adverse events specific to intracameral or subconjunctival antibiotic administration.¹

Because the pooled analysis combined randomized and nonrandomized studies, each evaluated with a different bias-assessment tool, residual confounding across the underlying study population cannot be fully excluded. This reliance on retrospective data is common across the antibiotic injection literature, as prospective, placebo-controlled trials are widely considered difficult, costly, and potentially unethical given the rarity of endophthalmitis.² The study authors did not specify individual antibiotic agents, dosing protocols, or administration routes used across the 54 included studies in the available summary. This detail would clarify which antibiotic injection strategies drove the observed benefit.

"One important barrier for US surgeons is that we still do not have a product approved for intracameral use. In many settings, this means surgeons must use local compounding pharmacies to prepare the intracameral drug, which creates a risk of TASS if there are any compounding process issues,” Wisely said. “Additionally, this study on endophthalmitis risk does not address the risk/benefit analysis of use of other topical agents, such as steroid and NSAIDs, that are common in postoperative drop protocols."

Confirmation of these details in the original publication would help clinicians interpret the applicability of the pooled findings to specific antibiotic injection protocols used in practice. Because the source material summarizes aggregate results without study-level detail, additional context from the full publication would strengthen confidence in the reported estimates.

Which patients benefit most from dropless cataract surgery protocols?

Dropless cataract surgery, which relies on intraoperative antibiotic and corticosteroid administration rather than a postoperative topical regimen, has gained attention as a strategy to improve adherence, simplify care, and reduce postoperative complications.¹ These findings support antibiotic injection as a component of the dropless approach, and sensitivity analyses confirmed the magnitude of benefit across the pooled dataset.¹

Reference
1. Ramos, M., Barbosa, L. M., Ramos, S. D. M., Ramos, L. D. M., Costa, J. R. G., de Mattos, J. V., & Hida, W. T. (2026). Antibiotic Injection in Cataract Surgery and Risk of Endophthalmitis: A Bayesian Meta-AnalysisJournal of Cataract & Refractive Surgery https://doi.org/10.1097/j.jcrs.0000000000002045
2. Haripriya A. Antibiotic prophylaxis in cataract surgery - An evidence-based approach. Indian J Ophthalmol. 2017 Dec;65(12):1390-1395. doi: 10.4103/ijo.IJO_961_17. PMID: 29208819; PMCID: PMC5742967.