Treatments for DED Associated With MGD Require Future Evaluation, Development

Future evaluation of existing treatments and development of new treatments is required to treat dry eye disease (DED) that is associated with meibomian gland dysfunction (MGD), according to a review published in Ophthalmology and Therapy. Treatments specifically targeting DED associated with MGD have been evaluated in a limited number of clinical trials.

MGD has been found to be the primary cause of evaporative DED and is highly prevalent, with an estimated prevalence of 35.9% in a meta-analysis of population-based studies. Asian countries tend to have higher rates of MGD compared with other regions, such as the United States and Europe. DED and MGD have been associated with older age generally, but population-based studies have also found a high prevalence in the age group of 20 to 30 years. This review aimed to “summarize the pathophysiology of DED associated with MGD…and then to summarize the research evidence regarding available treatments.”

The researchers used the MEDLINE database for their search conducted in April 2022. All studies were in English, and bibliographies were also searched for additional studies.

Current best practices suggest a 2-tiered approach to the diagnosis of DED, where it is established that the patient has DED before a differential diagnosis is evaluated for any MGD-related evaporative dry eye, aqueous deficient dry eye, or a combination.

Treatment for DED that is associated with MGD is to restore the tear film lipid layer and to decrease evaporation in order to reduce the ocular signs and symptoms. Eyelid hygiene, warm compresses, and ocular lubricants are ways for patients to manage their DED associated with MGD before moving on to office-based therapies and prescription medications should those remedies not work.

Eyelid hygiene is recommended twice daily for patients. Eyelid cleanser, combined with diluted baby shampoo, reduced signs and symptoms of DED and MGD in a randomized, contralateral eye study. However, only the cleanser improved the tear film lipid layer and reduced ocular inflammatory markers. Another study found that both had comparable improvements on ocular symptoms.

Warm compresses are used to increase liquification and flow of meibum. A longitudinal study found that warm compresses applied for 12 weeks altered the tear fluid lipidome. Randomized trials also found improvements in tear film and meibomian gland function parameters with warm compresses.

A randomized trial found that ocular lubricant lipid-containing eye drops were able to provide greater benefits for patients with evaporative DED. Long-term complicance was found to give MGD-specific benefits when treatment continued for 6 months. Ocular surface retention time for lubricant eye drops was found to be limited, however.

Multiple studies found that oral omega-3 fatty acids were associated with greater improvements in tear film break-up time (TFBUT) and Schirmer test results in patients with DED. Postmenopausal women with DED saw an improvement in their ocular symptoms when using omega-3 and omega-6 fatty acids as supplements. However, more recent studies found that, although both groups had improvement, there was no significant difference in the outcomes.

Manual expression was found to improve ocular symptom score, Ocular Surface Disease Index (OSDI), TFBUT, and meibum quality and expressibility. Microbelpharoexfoliation devices were found to be more effective combined with manual scrubs than manual eyelid scrubs alone in one study but did not improve OSDI score or meibomian gland secretion in a separate study. Thermal pulsation had limited number of studies on its effectiveness. Intense pulsed light was poorly understood in its application to improving MGD and DED symptoms. The few randomized trials evaluating intraductal probing found that improvements in signs and symptoms came in the first study and symptoms but not signs improved in the second study.

Effectiveness of topical antibiotics was mixed, as 1 study found that topical azithromycin was effective in improving meibum grade whereas a second study found that effects of topical azithromycin were not significantly different than the effects of an oral doxycycline. However, more studies found that azithromycin could be preferable to doxycycline in patients with MGD. There are no prescription pharmacologic products that have been specifically approved by the FDA for the treatment of DED associated with MGD.

The researchers concluded that, although there are available treatments for DED, there are only a limited number of treatments that have been evaluated in adequately powered, rigorously designed clinical trials that address their efficacy and safety for patients with DED associated with MGD. The researchers believe that the “development of pharmacologic agents targeted to the management of DED associated with MGD will improve therapeutic options and allow for a more individualized approach.”

Reference

Sheppard JD, Nichols KK. Dry eye disease associated with meibomian gland dysfunction: focus on tear film characteristics and the therapeutic landscape. Ophthalmol Ther. Published online March 1, 2023. doi:10.1007/s40123-023-00669-1