A prospective randomized evaluation of topical gatifloxacin on conjunctival flora in patients undergoing intravitreal injections.

PURPOSE

We sought to assess the efficacy of 3-day topical gatifloxacin use in combination with povidone-iodine (PVI) versus PVI alone in eliminating conjunctival bacterial flora in patients scheduled to undergo intravitreal (IVT) injection.

DESIGN

Prospective, randomized single-blind clinical trial.

PARTICIPANTS

We included 129 patients scheduled to undergo 273 IVT injections at California Vitreoretinal Center at Stanford University.

METHODS

Study patients were randomized to self-administration of gatifloxacin drops for 3 days before injection, or no pretreatment antibiotics. Cultures were collected from the bulbar conjunctiva at the injection site and at the corresponding location in the fellow eye before PVI preparation. After topical PVI treatment and immediately before injection, a third culture was obtained at the injection site. Additionally, the injection needle was also cultured after the procedure.

MAIN OUTCOME MEASURES

Incidence of positive bacterial samples collected from injection site conjunctiva and injection needles.

RESULTS

Three-day gatifloxacin use resulted in a significantly lower rate of SeptiChek (Becton Dickinson, Franklin Lakes, NJ) positive cultures compared with untreated controls (21% vs 48% respectively, P = 0.005). After topical PVI, the rate of positive bacterial cultures in gatifloxacin-treated and control eyes were similar (8% and 4%, respectively; P = 0.324).

CONCLUSIONS

Although 3-day topical gatifloxacin use is effective in reducing the frequency of conjunctival bacterial growth relative to untreated eyes, antibiotic use confers no additional benefit in combination with PVI than eyes receiving PVI alone. This supports that topical PVI is an effective preinjection monotherapy for infection prophylaxis in the setting of IVT injections.