PURPOSE: To assess evaluate the accuracy of intravitreal drug administration in the treatment of endophthalmitis and to suggest a reproducible and accessible technique for this procedure. METHODS: To assess the retained volumes in needles used for the intravitreal injection of antibiotics using an analytical scale. RESULTS: Means and standard deviations of retained volumes in the 26, 22 ( 25 x 0.7 mm and 30 x 0.7 mm ) and 18 G were respectively 0.051±0.006, 0.056±0.005, 0.055±0.004 and 0.075±0.004 for needles Ryncos® and 0.050±0.003, 0.056±0.002, 0.063±0.002 and 0.084±0.004 for Becton-Dickinson®. There were statistically significant differences in the retained volumes between the two needle brands for 26, 22 (30 x 0.7 mm) and 18 G needles with p = 0.01, p < 0.01 and p < 0.01 respectively. No difference was found only for 25 x 0.7 mm 22 G needle with p = 0.83. CONCLUSION: Most needles used for intravitreal injection hold a retained volume in the reserve needle compartment that should be considered during the injection technique, therefore minimizing errors during intravitreal injection of antibiotics.
Endophthalmitis; Vitreous body; Antibiotics; Injections; Medication errors