Dry Eye Dx and Tx
Lessons from the IWMGD
BY WILLIAM TOWNSEND, OD, FAAO
Over the past two decades, the focus on dry eye disease has gradually shifted from aqueous deficiency to an evaporative (i.e., lipid deficient) etiology (DEWS Research Subcommittee, 2007; Bron et al, 2014; Nichols, 2011; Geerling et al, 2011). In 2011, the results of The International Workshop on Meibomian Gland Dysfunction (IWMGD) reports were published, offering a treasure trove of information concerning the most common cause of dry eye. It is available for downloading at no charge (www.iovs.org/content/52/4/2050.full).
Dry Eye New Year’s Resolutions
Drawing from the management and treatment section, I suggest that we adopt the following:
1. Evaluate the eyelids and meibomian gland (MG) secretions of adults and teens. It only takes a few seconds to scan the lids for signs of gland stenosis, neovascularization, and inflammation. Routinely apply pressure to the lower lids just below the lash line with a cotton-tipped applicator or your fingertip. Surprisingly, asymptomatic individuals can have very few or no functioning glands. In some cases, functioning glands produce thick, cloudy secretions caused by altered lipid profiles; these do little to prevent evaporation and lubricate the eye.
2. Prescribe home-based therapy (i.e., lid hygiene). According to the IWMGD, “Lid hygiene is regarded as the mainstay of the clinical treatment of MGD. It usually consists of two components: application of heat and mechanical massage of the eyelids.” Hot, moist towels and rice bags that we used in the past to heat the lids have been replaced by microwavable masks that produce and retain warm, moist heat over a longer period of time. Radiant heat in the form of a 250-watt infrared lamp positioned 50cm from patients has also been utilized successfully as lid therapy. Regardless of the heat source, patients must massage and express lids after heating to open blocked glands and allow meibum to exit.
3. Prescribe anti-inflammatory agents to address the underlying cause of MGD (Geerling et al, 2011; Schaumberg et al, 2011). Inflammation is a critical contributor to the genesis and ongoing disease processes in MGD. Topical agents successfully address this. Steroid drops are beneficial in managing MGD-related inflammation. Long-term use of any steroid must be carefully monitored; even “soft steroids” may cause intraocular pressure (IOP) elevation in susceptible individuals. Novack (1998) reported IOP elevations of greater than 10 mmHg with 1.7% of individuals being treated with loteprednol compared to 6.7% of those taking prednisolone acetate.
Topical macrolides, especially azithromycin, have demonstrated potent anti-inflammatory effects on the MGs and may be used over extended periods. They are also beneficial in reducing bacterial flora thought to contribute to lid inflammation. Findings from the IWMGD suggest that topical cyclosporine reduces inflammation in MGD, but there are no definitive studies showing that it alters the composition or quality of meibum. Some oral antibiotics reduce MG inflammation. Because doxycycline and minocycline are lipophilic, they are preferred over tetracycline. Doxycycline and minocycline have been found to be clinically useful in treating MGD at lower (sub-antibiotic) dosing levels. Essential fatty acids, primarily the omega-3s and gamma linoleic acid, have been identified as potential therapy, but definitive studies still need to be conducted to establish their effects on the secretory glands.
The IWMGD, particularly the section on treatment, will enhance your understanding of the disease, improve patient care, and give you a new appreciation for the importance of MGs. CLS
For references, please visit www.clspectrum.com/references and click on document #230.
Dr. Townsend practices in Canyon, Texas, and is an adjunct professor at the University of Houston College of Optometry. He is president of the Ocular Surface Society of Optometry and conducts research in ocular surface disease, lens care solutions, and medications. He is also an advisor to Alcon, B+L, CooperVision, Tearlab Corporation, and Johnson & Johnson Vision Care. Contact him at firstname.lastname@example.org.