Corneal sensitivity in dry eye disease: A systematic review

Abstract

Background

Dry eye disease (DED) is a worldwide prevalent condition; however, its pathophysiology is not well understood. Corneal nerves play a primary role in DED, and a better understanding of the changes to their morphology and function is required. This systematic review investigated changes to the function of corneal nerves.

Methods

Relevant literature from inception to September 10, 2025 was searched for in PubMed, Web of Science and Scopus, following the PRISMA statement. Studies measuring corneal sensitivity in patients with DED and in healthy controls were included. Publication selection and analysis were conducted independently by two authors.

Results

Twenty-five studies involving 1580 participants (1001 with DED and 579 healthy controls) were included. Nineteen studies used the Cochet-Bonnet aesthesiometer and found a consistently reduced corneal sensitivity in patients with DED. No consistent correlation was found between corneal sensitivity and DED severity, possibly due to heterogeneity of study design and methodology. Six studies used a variant of the Belmonte air jet aesthesiometer, reporting inconsistent results for mechanical corneal sensitivity. Increased sensitivity in DED patients was reported, using a stimulus at ambient temperature. One study used the Brill aesthesiometer and found reduced corneal sensitivity in DED patients.

Conclusion

Cochet-Bonnet measurements suggest a decreased mechanical corneal sensitivity in DED patients. Air jet aesthesiometry results were inconsistent, indicating variable responses from functionally different corneal nerve endings. Future research should employ reliable corneal sensitivity measurement methods with a wide stimulus range and standardised study designs to improve understanding of changes in corneal sensitivity in dry eye disease.