Tear Film Instability More Severe in Patients With Dry Eye, Diabetes

Individuals had more severe tear film instability, orifice plugging, and lid margin abnormalities if they had type 2 diabetes and dry eye compared with those who had dry eye alone, according to a study published in International Ophthalmology.¹ This finding can help introduce interventions for those with type 2 diabetes and dry eye to help address the possibility of worse symptoms.

Individuals with dry eye and type 2 diabetes had more severe symptoms of dry eye | Image credit: Kryuchka Yaroslav - stock.adobe.com

Dry eye disease (DED) is a condition that affects the eye, primarily due to the eyes not being able to produce enough tears.² The prevalence of dry eye varies throughout the world, including between 16.7 million and 50.2 million in the US alone.³ Pooled prevalence in China in 2014 was 17.0%, representing a higher prevalence of dry eye in this country compared with the US.¹ Type 2 diabetes (T2D) is a chronic disease that is associated with inflammation and makes up about 90% of all diabetes cases. This study aimed to compare DED in those with and without DM, separated into a DED group and a DED-DM group, to measure differences in ocular surface parameters.

The study was conducted at the Baotou Medical College at the Inner Mongolia University of Science and Technology. All participants were older than 18 years and were diagnosed with DED between February and December of 2022 based on symptom assessment, tear break-up time (TBUT), ocular surface staining, and meibomian gland dysfunction. Any individuals who had an ocular injury or allergic conjunctivitis, had undergone surgery in the previous 6 months, or had an infection were excluded from the study.

Tear film stability was measured along with morphology and physiological function of the lid margin and meibomian glands during an ocular surface examination. Non-invasive tear breakup time (NIBUT), tear meniscus height (TMH), first tear breakup location, conjunctival congestion, lipid layer thickness, and lid margin images were all measured for the analysis.

There were 302 eyes from 151 patients that were included in the study, all of which were diagnosed with DED. There were 108 patients in the DED-DM group and 194 in the DED group. The median (range) of upper lid margin irregularity (0 [0-1] vs 0 [0-0]), lid margin vascularity, lid margin thickening grade, ciliary hyperemia (1.56 [0.26] vs 1.61 [1.45-1.79]), plugging of gland orifices, and upper meibomian gland dropout (2 [1-2] vs 1 [0-2]) were higher in the DED-DM group compared with the DED group. TMH, lipid layer thickness, first breakup location, lower meibomian gland dropout, conjunctival congestion, average NIBUT, and upper lid margin irregularity were not significantly different between the 2 groups.

Tear film breakup was most likely in the subnasal and subtemporal domains in both the DED-DM group (37.71% and 35.75%) and the DED group (33.71% and 36.54%). NIBUT, lid margin thickening grade, and lower lid margin irregularity had significant correlations with blood glucose level.

There were some limitations to this study. Confounding factors could not be ruled out of the analysis. Lid margin and meibomian glands were manually measured, which could increase subjectivity.

The researchers concluded that patients with DM and DED had more severe lid margin abnormalities, tear film instability, and orifice plugging compared with those who had DED alone.

“The damage of diabetes to the ocular surface needs the attention from clinicians across specialties,” the authors wrote. “Collaboration between ophthalmologists and endocrinologists is necessary for early detection, diagnosis, and treatment of diabetic ocular surface lesions to prevent more serious ocular surface damage.”

References

1. Hao Y, Wu B, Feng J, et al. Relationship type 2 diabetes mellitus and changes of the lid margin, meibomian gland and tear film in dry eye patients: a cross-sectional study. Int Ophthalmol. 2025;45:261. doi:10.1007/s10792-025-03636-w

2. Dry eyes. Mayo Clinic. September 23, 2022. Accessed June 30, 2025. https://www.mayoclinic.org/diseases-conditions/dry-eyes/symptoms-causes/syc-20371863

3. Dry eye statistics in 2023. Dry Eye Directory. Accessed June 30, 2025. https://dryeyedirectory.com/dry-eye-statistics/