Sir,

I have read the article by Ghasemi Falavarjani and Nguyen with great interest,1 which summarizes the best available evidence on adverse events and complications associated with intravitreal injections of anti-VEGF. However, some important papers on the role of antibiotics in the prevention of post-intravitreal anti-VEGF endophthalmitis (PIAE) were not referenced and some important issues need more thorough discussion.

It was shown in several retrospective studies that pre-injection and post-injection antibiotic treatment is not supported by sufficient evidence of efficacy.2

This was also recently supported by the prospective study, which however additionally presented significant risk factors for PIAE, ie no topical antibiotic immediately before injection, no immediate post-injection topical antibiotic, subconjunctival anesthesia, blepharitis, and squeezing during injections.3

It is of increasing awareness that antibiotic use causes antibiotic resistance and that globally antibiotics are overused in different fields of medicine, including ophthalmology.4 This may lead to loss of activity of major antibiotics and inability to use them in future, increase in multidrug resistance, increase in infections caused by antibiotic-resistant bacteria, and increase in health-care costs. The prognosis of the infections caused by antibiotic-resistant bacteria is much worse, and treatment is much more complicated.

The ARCANE (Antibiotic Resistance of Conjunctiva and Nasopharynx Evaluation), a prospective and longitudinal study, analyzed distant effects on bacterial resistance to repeated use of topical antibiotics. It was recently summarized and confirmed that repeated use of topical antibiotics on the conjunctival sac increases the rate of resistance of CNS to antibiotics.5

For many years antibiotic use in PIAE, although lacking convincing scientific evidence of efficacy, was based on empiric rationale and believed to be not harmful. Nowadays, we are aware that using antibiotics without clear benefit might be harmful.

Thus, we should carefully analyze all available scientific data on the topic and use antibiotics only when justified.