MANAGING DRY EYE

Tear film oriented therapy, which tackles dry eye symptoms by separating the components of the disease, allows physicians to take a targeted approach to dry eye disease management, reported Serge Doan MD at the 6th EuCornea Congress in Barcelona, Spain.

“Tear film oriented therapy is an approach that I adapted from the Dry Eye Society of Japan. In this approach, the components of the ocular surface are separated conceptually, allowing the clinician to target specific components of the system, such as the tear film, the epithelium or the underlying sensory nerves,” explained Dr Doan, Hôpital Bichat and Fondation A de Rothschild, Paris, France.

Dr Doan defined the tear film layers, namely the lipid, aqueous and mucous layers. Next comes the epithelium, with goblet cells and membrane associated mucins; the ocular surface inflammatory response; and the underlying sensory nerves.

He discussed both well-known treatments and newer therapeutic targets. He addressed the lipid layer first.

“Besides warm compresses and lid hygiene, oral tetracyclines are still the mainstay of treatment for meibomian gland dysfunction (MGD). But azithromycin has a longer half-life and a better safety profile. It has high tissue penetration and both anti-inflammatory and antibacterial lipase activity,” he said.

A multicentre controlled randomised study conducted by the Théa company demonstrated benefits of topical azithromycin versus placebo, particularly with repeated treatment cycles, he noted.

Dr Doan also discussed LipiFlow®, a heated ocular surface device with a pump mechanism designed to express meibomian gland secretions during a 12-minute treatment session.

“The effects at two weeks are superior to lid hygiene, and 80 per cent of patients respond,” he reported. The aqueous layer was next. “Of course, artificial tears and sodium hyaluronate should be tried first, moving on to punctal plugs,” he said.

Dr Doan noted that added benefit might be seen when a second plug is also placed in the superior punctum.

“Despite other advances, I believe scleral lenses are among the best treatment options for severe dry eye. The point of contact is on the sclera so they don’t touch the cornea or limbus.”

Dr Doan pointed out that a reservoir of tears develops under the lens, offering continual hydration to the ocular surface. Scleral lenses also have an analgesic effect, although some patients might find them difficult to insert, and cost, availability and the complexity of lens fitting remain barriers to their use.

Oral secretagogues such as pilocarpine and cevimeline are also used, but Dr Doan pointed out that their use was limited by side effects. Dr Doan advocated the use of cyclosporine eye drops such as Ikervis 0.1%®, approved in Europe since March 2015. The cationic emulsion of Ikervis offers electrostatic attraction, leading to higher corneal concentration of cyclosporine in animal models, he said.

Serge Doan: serge.doan@noos.fr