Efficacy and safety of mydriatic microdrops for retinopathy of prematurity screening: an external pilot crossover randomized controlled trial

Abstract

Objective To study the efficacy and safety of mydriatic microdrops compared with standard drops for retinopathy of prematurity (ROP) screening. Study design Preterm infants undergoing ROP screening received microdrops and standard drops of phenylephrine 1.67% and tropicamide 0.33% in a random allocation sequence at two consecutive weekly examinations. Primary outcome was pupil diameter measured by two masked observers at 45 (T45) and 90 (T90) minutes after instillation. Results Twenty-five infants were randomized. No differences observed in mean pupil diameter after either administration technique at all time points (T45 Mean Difference: −0.14; 95% Confidence Interval: −0.38, 0.09; p = 0.23). Heart rate values at T120 were lower after microdrop instillation (p = 0.046). Otherwise, adverse events did not differ after either administration technique. Conclusion This pilot study provides evidence of microdrops mydriasis efficacy, while justifying a full-scale trial to confirm their non-inferiority compared with standard drops and provide more data about safety. Trial registration ClinicalTrials.gov: NCT04623684.