Ophthalmic Insert versus Eye Drops for Mydriasis in Neonates: A Randomized Clinical Trial

Background: Eye drop treatment routinely used to obtain mydriasis prior to fundoscopy in neonates requires repeated instillations of mydriatic agents that can lead to systemic side effects. Objectives: The aim of this study was to compare the mydriatic efficacy and tolerance of administration of phenylephrine and tropicamide via the ophthalmic insert Mydriasert® versus standard eye drop treatment in neonates. Methods: In this prospective, single-blinded, noninferiority study, 80 hospitalized neonates (age < 18 months) requiring bilateral fundus examination were randomized to receive eye drops (repeated instillations of 2.5% phenylephrine and 0.5% tropicamide) or the insert. The primary outcome was mydriasis suitable for fundoscopy 75 min after mydriatic agent introduction (T75). Results: Mydriasis was successfully achieved in both eyes at T75 in 97.5% (n = 39/40) of the insert group patients versus 90% (n = 36/40) receiving eye drops (between-group difference 7.5%, demonstrating noninferiority). Mydriasis remained stable in 60.0% of patients (n = 24/40) in the insert group versus 15% (n = 6/40) in the eye drop group (p < 0.0001). The insert group required fewer nursing interventions than the eye drop group (p = 0.0001). Mean blood pressure were significantly higher in the insert versus the eye drop group (p < 0.0001 and p = 0.0003, respectively); mean heart rate was not significantly different between the groups (p = 0.37). In the insert group, 2 patients reported an adverse event (bradycardia, n = 1, and gastroesophageal reflux, n = 1; both appeared to be related to neonate pathology). Conclusions: The degree of mydriasis achieved with Mydriasert® was noninferior to that obtained with eye drops. The insert appears to be safe to use in neonates without a history of increased vagal tone or gastrointestinal reflux.