According to researchers at the University of Waterloo, while preservative-free drops are best for severe dry eyes, they are not the only option to consider in the management of more mild stages of the disease.
"The preservative benzalkonium chloride (BAK) is known to irritate the surface of the eye and should be avoided in all dry eye patients, however, there is good evidence that alternatively preserved drops can be safely used in mild to moderate cases.” said Karen Walsh, a Clinical Scientist at Waterloo’s School of Optometry and Vision Science and the Centre for Ocular Research & Education. "Preservative-free drops can be more expensive, and many are packaged in single-dose containers that can be difficult for elderly patients to use.
“This study provides an important recommendation to eye care practitioners: they have more options for treating mild to moderate dry eye than they may think.”
As part of their research, Walsh and co-author Lyndon Jones reviewed a range of studies including clinical trials and laboratory testing which showed that artificial tears containing alternative preservatives are significantly safer to the surface of the eye than BAK-preserved drops.
“It is important for patients with symptoms of dry eye to seek medical advice when choosing which drops are best. An examination with their eye care professional can diagnose the type and severity of dry eye, which will result in more effective treatment and ongoing management of the condition.” said Walsh.
This literature review, The use of preservatives in dry eye drops, authored by Walsh and Jones was recently published in the journal Clinical Ophthalmology.