Meibomian gland dysfunction (MGD) is typically framed as a symptomatic disease — grittiness, burning, fluctuating vision and fluctuating tear stability bring patients to the clinic. But what if the disease is already well underway before symptoms appear? A new cross-sectional study from Mahidol University in Thailand suggests precisely that, revealing strikingly high rates of meibomian gland abnormalities in adults who report no dry eye symptoms at all.
The researchers evaluated 60 volunteers aged 31–60 years, all of whom recorded a DEQS score ≤14 and therefore met the study definition of an asymptomatic population. Participants underwent a comprehensive ocular surface assessment — including slit-lamp biomicroscopy, fluorescein tear breakup time (FTBUT), Schirmer I testing, LipiView interferometry, meibography and gland expressibility and meibum quality grading.
One of the most surprising findings appeared in the first results of the study: 71% of upper eyelids and 51% of lower eyelids demonstrated meiboscore ≥1, indicating measurable gland dropout. Lid margin abnormalities were also common. Telangiectasia was present in 82% of subjects, and gland plugging in 84%, underscoring that visible signs of MGD are not limited to symptomatic patients.
Despite notable gland changes, overall tear function remained reasonably preserved: Median FTBUT was 5.04 seconds, a borderline value that did not differ significantly across age groups; lipid layer thickness (LLT) averaged 61 ± 20 μm — squarely within the range of healthy populations reported in previous interferometry studies; corneal staining abnormalities were mild, limited mostly to Oxford Grade 1.
Yet early functional decline is detectable. The Schirmer I test showed significant age-related differences, and minimum LLT was significantly lower in the oldest age group, suggesting diminishing compensatory capacity.
The dissociation between gland morphology and patient symptoms highlighted in the study raises important clinical questions. Are these individuals in a pre-symptomatic stage of MGD? And could intervention at this stage prevent future evaporative dry eye?
The study authors note that more than half of this asymptomatic cohort had gland dropout and poor expressibility, yet maintained adequate lipid layer function — implying a threshold beyond which symptoms abruptly emerge. They believe their findings make a strong case for proactive screening, especially in middle-aged adults where Meibography may reveal early gland loss before symptoms develop, and preserving LLT and delaying gland dropout may rely on earlier intervention than previously assumed.
MGD may be silently progressing in many of our “healthy” patients. The message is clear: absence of symptoms does not mean absence of disease — and earlier detection could help to shift the trajectory of dry eye development.
