BLOG: Meibomian gland imaging: Treatment is easier when you see the problem
Oy, will ya lookit the time. How did it get to be November already?
With all of my lockdown-induced free time, you’d think I would have already gotten around to writing about a journal article that appeared in January. Yeah, no. I have no idea what I’ve been doing with myself. Anyway, somehow this really awesome article by Xiao and colleagues in the American Journal of Ophthalmology just now floated to the top of my “this is cool” pile. While the take-home message of the study turns out to be pretty obvious, the authors put some objective muscle behind the message: In order to effectively treat meibomian gland disease (MGD) you have to look at the patient’s meibomian glands.
It seems obvious, right? I mean, pretty much every other specialty in medicine now gets an image of some sort to determine that treatment is necessary. Imaging also helps determine the severity of a disease process, which in turn can determine the level of aggression necessary to adequately treat that disease. Can you imagine proceeding with treatment for a patient with heart disease without first seeing either a cardiac cath, echo or both? Internists on Twitter often state that those stethoscopes draped around their necks are really just for show. No one is diagnosing pneumonia by listening to breath sounds without also getting a chest X-ray.
A total of 447 right eyes with established MGD were evaluated in the study. Every patient filled out an OSDI questionnaire and all of the usual exam suspects were included (tear osmolarity, tear breakup time, staining and so on). In addition, meibum expressibility and quality were assessed, and meibography images were obtained using the Oculus Keratograph. Patients were categorized as having either high or low meibum delivery. Unsurprisingly, the low delivery patients experienced a greater degree of ocular symptoms and staining, both of which were statistically significant. High delivery MGD patients generally looked and felt better.
Here’s where it gets interesting: A significant percentage of high meibum delivery patients had extensive MGD on meibography. The clinical exam findings and symptoms in this subset of patients were indistinguishable from those of patients with minimal MGD. None of the other DED tests identified these patients. To know that they were at high risk for worsening symptoms over time, it was necessary to image the glands. To no one’s surprise, low meibum delivery was seen in patients with both severe gland destruction and gland obstruction. In order to determine why delivery is low, the study demonstrated that it is necessary to image the glands. The surprise finding is that there exists a subset of MGD patients who are still functioning at a relatively normal level who have sustained severe gland damage.
DED with any sign of MGD means that imaging of the glands is necessary.
If we are to treat MGD effectively, it is necessary to know what the affected glands look like. While Xiao and colleagues used the Oculus instrument, there are a number of other very effective options. LipiView and LipiScan (Johnson & Johnson Vision) and Meibox (Box Medical Solutions) are widely used in the U.S. The finding that extensive disease can exist in the face of relatively normal exam findings means that we run the risk of missing the opportunity to begin treatment prior to crossing a threshold beyond which we may not be able to effectively prevent worsening of MGD symptoms.
It may sound obvious, but it bears saying again: Best practices of MGD treatment include imaging the glands.