Randomized Controlled Trial Comparing the Efficacy of Mydrin-P Microdrops Over Standard Dose Mydrin-P for Pupil Dilation in Retinopathy of Prematurity Examination.

PURPOSE: To compare the efficacy of a reduced dose of Mydrin-P (0.5% tropicamide and 0.5% phenylephrine hydrochloride) (Santen Pharmaceutical) using micro-drops with standard Mydrin-P eye drops for retinopathy of prematurity (ROP) examinations.

METHODS

A prospective, randomized controlled, non-inferiority study was conducted in a single neonatal intensive care unit in Hong Kong. Eighteen infants with an estimated gestational age at birth of 32 weeks or less and/or birth weight of 1,500 g or less were recruited and randomized to receive either standard Mydrin-P eye drops or Mydrin-P microdrops (one-third of the standard dose). All patients were subsequently examined by an ophthalmologist for the presence of ROP. Serial pupil diameters and other clinical parameters were also measured after mydriatics were applied.

RESULTS

Eighteen infants with 46 eye examinations for ROP were included. All fundus examinations with microdrop instillation led to successful ROP assessments with no statistically significant difference compared to standard eye drops (P = .233). Mean pupil diameter did not differ between the microdrop (5.73 mm) and standard eye drop (5.47 mm) groups at the time of examination. No statistically significant difference in systemic side effects was observed between the two groups.

CONCLUSIONS

Mydriatic Mydrin-P microdrops demonstrated similar efficacy compared to standard Mydrin-P eye drops and should replace standard Mydrin-P for ROP screening in preterm infants with potentially fewer side effects.