Dry eye syndrome (DES), also known as keratoconjunctivitis sicca (KCS); is the condition of having dry eyes. Other associated symptoms include irritation, redness, discharge, and easily fatigued eyes. Dry eye occurs when either the eye does not produce enough tears or when the tears evaporate too quickly. The researcher did the trial compared eye drops containing a biosynthetic form of an enzyme called DNase with eye drops without the enzyme. DNase breaks up nucleic acid-based material on the surface of the eye.
In severe dry eye disease, which often accompanies diseases such as Sjogren’s syndrome and ocular graft-versus-host disease; the inflammation in the corneal tissue can become extreme enough to cause disabling eye pain and sensitivity to light. In previous research; Jain and colleagues discovered that strands of DNA form webs on the surface of eyes affected by severe dry eye disease. This material causes an inflammatory response that further irritates the eye.
Number of white blood cells
“There is an increase in the number of white blood cells are neutrophils that gather on the surface of the eye. Neutrophils release DNA which forms webs on the cornea called neutrophil extracellular traps; which cause inflammation of the ocular surface and attract additional neutrophils in a vicious cycle.” Normally, enzymes present in tears chop up and clear DNA and other debris on the cornea, but in patients with dry eye disease; there is not enough DNase to clear the material.
The researchers found that participants in the DNase group had a statistically significant and clinically meaningful reduction in corneal damage at eight weeks compared with the placebo group. Questionnaire scores related to symptoms also reflected significant improvement among patients in the DNase group compared with placebo; who also had reduced amounts of corneal DNA webs and other material on the surface of the eye.
DNase eye drops
“The data from this early clinical trial suggests that DNase eye drops may safe and effective for treating severe dry eye; they look forward to conducting larger randomized trials to definitively prove its efficacy,” Jain said. DNase is currently approved by the U.S. Food and Drug Administration to treat cystic fibrosis. Its use for treating severe dry eye that does not respond to other medications is still considered experimental by the FDA.
“The burden of severe dry eye is much greater than just having an occasional feeling of dryness. “It can severely compromise the quality of life to the point of disability and can compromise a person’s vision. There are currently only two approved drugs to treat dry eye, and they do not work for everyone; especially those with severe disease, so having a new drug that can treat the disease is very important.”
This research was supported by Genentech, National Eye Institute grants R01 EY024966 and P30 EY001792; a Research to Prevent Blindness Physician Scientist Award and a UIC Chancellor’s Innovation Fund Award. Jain is the inventor on a patent assigned to the University of Illinois at Chicago that covers the use of DNase to treat dry eye disease.