Study shows castor oil in artificial tear decreases evaporation, increases comfort
PHOENIX – Researchers from the Optometric Technology Group in London have found that an eye drop containing castor oil and demulcents was associated with a reduction in tear film evaporation rate and increase in ocular comfort.
According to a poster here at Academy 2012, the castor oil was detected in the basal tear after 30 days of use and at least 3 hours after the last eye drop instillation.
“What surprised us was the 30-day visit,” Cecile A. Maissa, PhD, AMIChemE, told PRIMARY CARE OPTOMETRY NEWS. “It looks like it stays in the tears for at least 3 hours.”
Maissa added, “There was a shift to higher evaporation when no oil was in the tears.”
Researchers conducted a prospective bilateral evaluation of evaporative dry eye sufferers using Refresh Optive Advanced (Allergan) for 1 month. Patients were seen at baseline and at 30 days. Valid data was elicited from 33 patients.
“At both visits combined, a detectable amount of castor oil in the tear samples was associated with a lower evaporation rate at 30% [low] relative humidity, but a similar comfort than when castor oil was not detected,” the poster stated. “Prior to eye drop instillation at day 30, when castor oil was present in the tear samples, the evaporation rate was lower at both 30% relative humidity and 40% [normal] relative humidity than at baseline.”
"A significant effect of treatment was seen at 1 month,” Maissa said.
Disclosures: The study was sponsored by Allergan. None of the authors has any relevant financial interests.