An ophthalmic spray containing 1% tropicamide and 2.5% phenylephrine has been shown by American researchers to be as effective as traditional eye drops for pupillary dilation in children. Their study, published by Ophthalmology, also showed the spray was preferred by most of the participants. 

Measuring non-inferiority of change in maximum pupil diameter and change in pupillary constriction percentage 30 minutes after dilation, the researchers analysed 134 eyes of 67 participants, with 67 eyes randomised to eye drops and 67 randomised to spray. Spherical equivalent refractive error and baseline pupillary characteristics were similar between groups. 

Maximum pupil diameter was 7.65mm (95% confidence interval [CI]) in the eye drop group and 7.72mm (95% CI) in the spray group. Change in maximum pupil diameter was 2.15mm (95% CI) in the eye drop group and 2.48mm (95% CI) in the spray group. Change in pupillary constriction percentage was –30.29% (95% CI) for eye drops and –32.29% (95% CI) for spray.  

Compared with eye drops, the spray met non-inferiority criteria for maximum pupil diameter and pupillary constriction percentage, the researchers said, with 67% of participants saying they preferred the spray over eye drops.