Lubricating eye drops mimic composition of human tears

Sodium carboxymethylcellulose (CMC) 0.25% lubricating eye drops (TheraTears, Advanced Vision Research) mimic the composition of the human tear film and promotes healing of irritation of the ocular surface caused by dry eye, according to the recently released final report of the Dry Eye Workshop.

Key Points

In the section of the DEWS report dealing with current therapies for dry eye, the panel of specialists stated, "The term 'artificial tears' is a misnomer for most products that identify themselves as such, because they do not mimic the composition of human tears. Most [artificial tears] function as lubricants, although some more recent formulations mimic the electrolyte composition of human tears (TheraTears)."

A bilateral therapeutic approach

"Increased tear osmolarity plays a central role and is one of the most sensitive and specific indicators in patients with dry eye," he explained further. "In conjunction with increased tear film osmolarity, inflammatory mediators create a vicious cycle that further negatively affects the ocular surface. Sodium CMC 0.25% does a remarkable job of reversing this process in the patient with dry eye."

Dosing, therefore, provides a two-pronged therapeutic approach, lowering the osmolarity of the tear film and providing the electrolytes needed by the ocular surface, including conjunctival goblet cells, for maintenance and repair.

"These are the claims to fame of sodium [CMC] 0.25%," Dr. Omar stated. "[Sodium CMC 0.25%] is also a tear formulation that has been shown in some scientific data to increase goblet cell density.

"The only other drop that has claimed to improve the quality of the tear film is [cyclosporine emulsion (Restasis, Allergan)], the major obstacles to which are cost, insurance coverage, and the prolonged latency of clinical improvement," he said.

Clinical experience

Dr. Omar said he has been using sodium CMC 0.25% for about 2 years. Because of the product's effects, he considers it the primary therapy for his patients with dry eye, most of whom are postmenopausal women.

When assessing a patient with dry eye, sodium CMC 0.25% is the first treatment he prescribes, Dr. Omar said.

"The reason for this is that I need a product that is going to work relatively quickly to help bolster patient compliance with the regimen," Dr. Omar said. "If a clinician uses a product that does not subjectively and objectively improve a condition rapidly, patient compliance and follow-up will suffer. In addition, [sodium CMC 0.25%] has a very good side effect profile."

Dr. Omar said he prefers the preservative-free form of sodium CMC 0.25% because of the quality control in the foil-sealed packet compared with the bottled formulation.