Abstract
Purpose :
Ocular and systemic side-effects are an important reason to discontinue eye medication. Side-effects are dose-dependent to a great extend, so establishing the minimal effective dose is of great importance. This study was performed to assess whether clinical equivalent mydriasis can be achieved with reduced size tropicamide eye drops compared to regular tropicamide eye drops.
Methods :
Randomised single-blind cross-over trial in 30 healthy volunteers. On day 1, one intervention group received a micro drop (2,4 microliter) in both eyes, the other group a regular eye drop (38 microliter). Pupil size measurements were performed 10 times during a 2 hour timeframe. Side effects were assessed using a questionnaire. The measurements were repeated with the other eye drop after 7 days.
Results :
After 40 minutes maximum pupil dilation is reached. The mean difference in pupil size (within subject analysis) between the micro drop and the regular drop is 0,41 mm (statistically significant: t=8,43; df=28; p<0.001). The non-inferiority margin of 0,5 mm lies above the confidence interval (0,39-0,49 mm).
All 30 subjects report to prefer the micro drop. Less discomfort is experienced and less complaints of impaired vision are reported with the micro drop.
Conclusions :
Non-inferior mydriasis can be achieved with a micro eye drop that is 15 times smaller compared to a regular size eye drop tropicamide and less side-effects are experienced. All subjects prefer micro drops. Development of ocular micro drops offers new possibilities in improving treatments with eye drops.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.