Article

CLINICAL: DRY EYE

WHICH COMES FIRST?

BOTH INFLAMMATION AND OBSTRUCTION REQUIRE YOUR ATTENTION

WHICH CAME first, the chicken or the egg? It’s an age-old question yet to be answered. Similarly, O.D.s often debate whether inflammation or obstruction comes first in meibomian gland dysfunction (MGD). The question isn’t linear, and neither is the answer.

INFLAMMATION

Traditionally, inflammation (aka the chicken) was considered the root cause of dry eye disease (DED) patients’ suffering, regardless of whether it was aqueous deficient or evaporative.

Once palliative care, such as artificial tears, failed to resolve signs and/or symptoms, anti-inflammatory topical and oral drugs were employed. For example, steroid drops, despite increasing IOP, decrease inflammation. Cyclosporine ophthalmic emulsion 0.05% (Restasis, Allergan), an immunosuppressive compound, provides relief for many chronic DED patients without the risks of long-term steroid use. Also, some doctors report successfully quieting inflammation via the off-label use of ophthalmic azithromycin (AzaSite, Akorn). Meanwhile, oral therapeutics, such as doxycycline and minocycline can treat inflamation in MGD, ocular rosacea and corneal wound healing.

OBSTRUCTION

When it was established that 86% of DED was evaporative (aka the egg) in nature, the pendulum swung toward the management of obstruction (See tinyurl.com/EvapDED ).

While most eye care providers didn’t abandon anti-inflammatory drugs, emerging treatment options (thermal pulsation, punctal probing and intense pulse light) trended toward the management of impacted glands to avoid meibomian gland dilation and atrophy. The argument for early intervention and aggressive treatment makes sense: If glands are congested with inspissated meibum, logic (and published research) dictates that patients find relief through evacuation.

IT’S NOT ONE OR THE OTHER

Some O.D.s view this treatment decision as one or the other. With the advent of new DED drugs, such as lifitegrast ophthalmic solution 5% (Xiidra, Shire), many O.D.s are experiencing a “reawakening” to the inflammatory origin of DED. However, the pendulum needn’t swing back the other direction: If doctors truly subscribe to the circular nature of DED, both inflammation and obstruction may require evaluation and treatment. Further, doctors now have at their fingertips a variety of tests to help isolate the influence of each.

LET’S REJECT THE QUESTION

Maybe the theoretical construct that either the chicken or the egg came first should be discarded. It’s conceivable that the two arrived on the scene at virtually the same time. Perhaps one opened the door for the other or created a hospitable environment, allowing its counterpart to thrive. Inflammation and obstruction are also likely to be intertwined and inseparable in the treatment of evaporative DED. Case closed. OM