The phenomenon of antibiotic resistance is a growing problem that often results from improper antibiotic prescription and usage. Several Ophthalmologists prescribe antibiotic drops even when not strictly necessary. This is frequently the case with patients who receive injections into the eye. In this instance, antibiotic misuse is especially relevant as intravitreal injections are one of the most common procedures in Ophthalmology. The purpose of this research is to determine the utility of antibiotic prophylaxis in patients who receive intravitreal injections. This study will be conducted in the form of a randomized-controlled clinical trial and will consist of two groups. The study group will be instructed to apply antibiotic drops before the procedure, while the control group will perform no prophylaxis. Injections will be administered using a standardized aseptic protocol, which includes disinfection of the conjunctiva with iodopovidone. Following disinfection, conjunctival swabs will be collected from all patients prior to the injection. Samples will be analyzed both qualitatively and quantitatively to determine whether the combination of topical antibiotic prophylaxis and iodopovidone is able to achieve greater disinfection of the conjunctival surface as compared to iodopovidone alone. The null hypothesis states that there will be no difference between groups, as iodopovidone alone is sufficient to achieve optimal surface disinfection. The proponents of this study would like to formulate definitive evidence that antibiotic prophylaxis has no utility in reducing the potential infectious complications of intravitreal injections, as iodopovidone alone achieves optimal surface disinfection. However, repeated courses of antibiotics in patients who receive multiple injections are not devoid of risk. In fact, they still increase the risk of selecting antibiotic-resistant bacteria, which can cause difficult-to-treat ocular infections later on.
As today (June 2021), there are no randomized-controlled clinical trials exploring the additive benefit of topical antibiotic prophylaxis as compared to iodopovidone alone in reducing the amount and composition of the conjunctival flora.
The confirmation of the null hypothesis - that topical antibiotic prophylaxis provides no added benefit in achieving greater disinfection of the conjunctiva as compared to iodopovidone alone - will provide scientific evidence that peri-procedural antibiotics are not needed when administering intravitreal injections.
This will hopefully reduce antibiotic prescriptions prior to intravitreal injections, thus reducing the likelihood of selecting antibiotic-resistant bacteria on the ocular surface, that can cause difficult-to-treat infections later on.