AimTo evaluate the effects of a proprietary formulated eye drop with Leptospermum spp honey versus a conventional lubricant eye drop on tear film properties in subjects with symptoms related to dry eye disease after 28 days of treatment.MethodsForty-six subjects with symptoms related to dry eye (Ocular Surface Disease Index (OSDI) score >12) were enrolled and randomly assigned to receive either the test formulated eye drop (Optimel by Melcare Biomedical Pty Ltd) or control eye drops (Alcon, USA) in this double-masked study. Inferior lipid layer thickness (LLT), tear film evaporation rate (TER), fluorescein tear film break-up time (TBUT), corneal staining and subjective symptoms (OSDI and visual analogue scales (VAS)) were measured before and after 28 days of instilling the eye drops.ResultsForty-two subjects completed the study (21 subjects in each group). After 28 days of treatment, TER showed a significantly greater reduction with the formulated eye drop compared with the control (p=0.01). TBUT showed a slight but not statistically significant increase with the formulated eye drop compared with the control (p=0.06), and a significantly greater reduction (improvement) in OSDI scores was observed with the formulated eye drop compared with the control (p=0.01). No significant differences were found between the two groups for inferior LLT, corneal staining and any of the VAS scores.ConclusionsThe formulated eye drops were effective in reducing tear film evaporation rate and were more effective for improving symptoms of dry eye compared with the control eye drops after 28 days of treatment.Trial registration numberNCT03622619.