According to the National Eye Institute (NEI), recent developments in dry eye disease research are leading to potential therapies designed to address the underlying causes of disease rather than simply providing symptomatic relief.
“Scientists are discovering how the tear film that coats the eye maintains homeostasis, or equilibrium, of its 3 main layers,” said George McKie, DVM, PhD, corneal diseases program director at NEI, in a press release that highlights some of the newest investigational therapies from NEI-funded research.
Lacritin
One novel therapy undergoing testing in clinical trials is a synthetic form of lacritin, a protein that stimulates basal tear production. Early investigations of the protein, discovered more than two decades ago by NEI-funded researcher Gordon Laurie, PhD, showed that ocular surface homeostasis is disrupted in individuals with lacritin deficiency. Animal studies previously demonstrated that a single dose of lacritin is sufficient to elevate basal tearing, with benefits of daily dosing lasting at least 1 week after therapy stops.
An industry-sponsored, 27-site clinical trial to investigate the use of synthetic lacritin in people with dry eye associated with Sjogren’s syndrome is underway, with results expected in early 2018.
Electrical stimulation
A team at Stanford University, led by Daniel Palanker, PhD, has developed an implantable device that electrically stimulates the lacrimal gland to produce tears. Additionally, the team recently discovered that stimulating multiple glands around the eye produces tears with lipids and mucins that closely resemble naturally occurring basal tears.
Corneal nerve sensitivity
Typically, the cooling from tear evaporation is sufficient to activate corneal nerves and trigger basal tearing. In some individuals, however, such cooling fails to trigger a response, spurring scientists such as Hiramitsu Hirata, PhD, of Weill Cornell Medical College to develop topical corneal nerve stimulators to increase nerve sensitivity.
Omega-3 supplements
While several small studies suggest that oral omega-3 fatty acids can benefit dry eye patients, they lack consistency in terms of the type and dose of omega-3 therapy used. Led by Penny Asbell, MD, at Icahn School of Medicine at Mount Sinai, New York, the Dry Eye Assessment and Management Study (DREAM) is the first large, independent, multisite investigation of omega-3 supplements for dry eye.
“In addition to evaluating the role of omega-3s in the outer, oily layer of tears, we expect to gain insights about the role of inflammation in dry eye. We hope to determine whether there are inflammatory biomarkers for dry eye,” Dr. Asbell said.