Comparison of Mucin Levels at the Ocular Surface of Visual Display Users With and Without Dry Eye Disease

Inclusion Criteria: * Participants who exposed to video display terminals for more than 1 year (at least 5 days per week and 6 hours per day) were enrolled and divided into two groups: (1) VDT users with DED and (2) VDT users without DED. DED was diagnosed according to the Tear Film and Ocular Surface Society (TFOS) DEWS II criteria: (1) Ocular Surface Disease Index (OSDI) score ≥ 13 and (2) one of these signs; fluorescein tear breakup time (TBUT) \<10 sec; abnormal ocular surface staining (\>5 corneal spots or \> 9 conjunctival spots). Exclusion Criteria: * a history of contact lens wear or ocular surgery within 2 year of the study visit; a history of previous ocular disease; topical or systemic therapies other than artificial tears within two weeks before recruitment; and inflammatory ocular diseases, ocular surface diseases, glaucoma and systemic diseases with ocular involvement, such as meibomian gland dysfunction, diabetes, and peripheral neuropathy.