Letters to the Editor
Previously the Diabetic Retinopathy Clinical Research Network (DRCR.net) reported a low rate of endophthalmitis achieved via a protocol requiring topical povidone-iodine, a sterile lid speculum, and topical anesthetic; not requiring topical antibiotics, sterile gloves, or a sterile drape.1 These results included 3838 injections of either ranibizumab or preservative-free triamcinolone. No antibiotics were given either before or after the injections in 1276 eyes. Of 3226 ranibizumab injections given between two DRCR.net randomized trials, three cases of endophthalmitis occurred, all in eyes receiving topical antibiotics for several days after the injection.
As of November 21, 2011, a total of 8027 intravitreal injections (1066 eyes) from single use vials have been administered across four DRCR.net randomized trials.2–5 Seven (two culture negative, and 5 culture positive) cases of endophthalmitis have occurred, including 6 (0.13% [n=4697]) that occurred with the use of topical antibiotics, compared with 1 (0.03% [n=3333]) that occurred without the use of topical antibiotics (P value = 0.25).(Table 1)
Table 1.
Cases of Endophthalmitis after Single Use Vial Intravitreal Injections in the Diabetic Retinopathy Clinical Research Network
| Case | Intravitreal Drug Injected | Culture Results | Povidone-Iodine Use | Pre-op Antibiotics | Post-op Antibiotics |
|---|---|---|---|---|---|
| 1 | Bevacizumab | Coagulase negative staphylococcus | Yes | No | No |
| 2 | Ranibizumab | Coagulase negative staphylococcus | Yes | Yes | Yes |
| 3 | Ranibizumab | Culture negative | Yes | No | Yes |
| 4 | Ranibizumab | Coagulase negative staphylococcus | No* | Yes | Yes |
| 5 | Ranibizumab | Streptococcus viridans† | Yes | No | Yes |
| 6 | Ranibizumab | Coagulase negative staphylococcus | Yes | No | Yes |
| 7 | Masked drug (either saline or ranibizumab) | Culture negative | Yes | No | Yes |
Among 8027 intravitreal injections in the Diabetic Retinopathy Clinical Research Network, this is the only study participant in which injections were performed without use of povidone-iodine, which was considered a protocol deviation. Since this event, the DRCR.net has clarified to participating investigators that no study injections may be performed without use of povidone-iodine over the injection site, even as a protocol deviation.
Scant growth of methicillin resistant staphylococcus aureus also was reported.
These updated results include an additional 2,057 injections without topical antibiotics and the endophthalmitis rate remains lower than injections with topical antibiotics. These results affirm, as previously reported, that a low rate of endophthalmitis can be achieved without topical antibiotics when the technique includes the use of topical povidone-iodine, a sterile eyelid speculum, and topical anesthetic. These prospectively accumulated results support similar outcomes noted in large retrospective case series and suggest that topical antibiotics before or after intravitreal injections, as given in the DRCR.net, are not likely reducing the risk of endophthalmitis.
Acknowledgments
Financial Support: Supported through a cooperative agreement from the National Eye Institute and the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services EY14231, EY14229, EY018817
Footnotes
Financial Conflicts of Interest:
Financial Disclosure: A complete list of all DRCR.net investigator financial disclosures can be found at www.drcr.net
References
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