ROP microdrops met the dilation margin; safety is still unresolved

In 102 preterm infants, 10.26-µL phenylephrine/tropicamide microdrops were noninferior to 26.58-µL standard drops for 45-minute pupil diameter. All examinations were completed, but this single-center trial was too small to establish rare-harm safety.

THE HOT TAKE

The smaller drop cleared an efficacy margin. It did not clear the question of rare harm.

A single-center trial in Chennai randomized 102 preterm infants undergoing retinopathy of prematurity screening: 52 received 10.26-µL microdrops through a sterile bottle adapter and 50 received 26.58-µL standard drops. Both groups received the same 2.5% phenylephrine plus 0.8% tropicamide formulation, one drop in each eye three times at 10-minute intervals.

At 45 minutes, mean pupil diameter was 6.54 mm (SD 0.52) with microdrops and 6.38 mm (SD 0.63) with standard drops. The microdrop-minus-standard difference was 0.16 mm, with a 95% CI from -0.07 to 0.38 mm. Because the lower bound stayed above the prespecified -0.5-mm margin, the noninferiority criterion was met.