Liraglutide eye drops protect the lacrimal gland and increase tear production in diabetic mice | Research

The takeaway

First identification of GLP-1R in lacrimal gland tissue, with diabetes-induced downregulation, inflammation, and fibrosis reversed by topical liraglutide eye drops that increased tear secretion through autophagy promotion.

GLP-1 eye drops for diabetic dry eye
First discovery of GLP-1R in the lacrimal gland opens a completely new therapeutic application: topical liraglutide restoring tear production in diabetic mice

What the researchers found

First: GLP-1R identified in lacrimal gland. GLP-1R downregulated in diabetes. Diabetes: lacrimal inflammation, fibrosis, atrophy, ↓tear secretion. Topical liraglutide: ↓inflammation, ↓fibrosis, ↑autophagy, ↑tear production. RNA-seq: inflammatory pathways enriched.

Why it matters

Diabetic dry eye affects millions and current treatments only address symptoms (artificial tears). GLP-1 eye drops could be the first disease-modifying treatment by protecting the lacrimal gland itself.

How the study worked

Type 1 diabetic mouse model. Phenol red thread tear test. RNA-seq of lacrimal gland tissue. GLP-1R expression analysis. Histology (inflammation, fibrosis). Topical liraglutide eye drops. Autophagy markers.

What this study cannot tell us

Type 1 diabetes mouse model. Topical formulation details not specified. Long-term safety of GLP-1 eye drops unknown. Translation to human diabetic dry eye needs validation.

How to read the evidence

First-of-its-kind preclinical discovery with RNA-seq and functional validation. Paradigm-shifting but needs clinical confirmation.

When this study was published

Published in 2025.

The bigger picture

GLP-1R is being discovered in more and more tissues—each discovery opens new therapeutic applications. Finding it in the lacrimal gland extends GLP-1 drug potential to ophthalmology and dry eye disease.

Questions still open

Could GLP-1 eye drops treat non-diabetic dry eye?
Does systemic semaglutide also improve tear production in diabetics?
What is the optimal GLP-1 eye drop formulation for clinical use?

Common questions

Could GLP-1 eye drops treat dry eyes in diabetes?

This study provides the first evidence that they could. Researchers discovered GLP-1 receptors in the tear-producing gland for the first time, found they are reduced in diabetes, and showed that liraglutide eye drops reversed the damage—reducing inflammation, scarring, and increasing tear production in diabetic mice.

Why do diabetics get dry eyes?

Chronic high blood sugar damages the lacrimal glands (which produce tears) through inflammation and scarring. This study showed the tear glands also lose GLP-1 receptors in diabetes, contributing to their dysfunction. Restoring GLP-1 signaling with eye drops helped heal the glands and restore tear production.

Read the original research

Characterization and Role of Glucagon-Like Peptide 1 Receptor in the Lacrimal Gland: Novel Insights into Diabetic Dry Eye Pathogenesis.

The American journal of pathology, 195(4), 797-810

View on PubMed ↗Publisher’s paper ↗

Citation

Sun, Yan; Zhang, Yue; Shi, Fan; Li, Ye; Wang, Congyao; Yu, Fenfen; Chen, Tingting; Dong, Xia; Xu, Yuqi; Zhao, Yu; Wan, Pengxia. (2025). Characterization and Role of Glucagon-Like Peptide 1 Receptor in the Lacrimal Gland: Novel Insights into Diabetic Dry Eye Pathogenesis.. The American journal of pathology, 195(4), 797-810. https://doi.org/10.1016/j.ajpath.2024.12.003