Correlation between tear film lipid layer thickness and transepidermal water loss from the ocular area in patients with dry eye disease and in healthy controls

PURPOSE: This study aimed to evaluate the correlation between tear film lipid layer thickness and transepidermal water loss (TEWL) from the ocular area in patients with short tear break-up time (TBUT)-type dry eye and healthy controls. METHODS: This prospective study included 25 eyes of patients with short TBUT-type dry eye disease and 25 eyes of healthy controls. RESULTS: Tear film lipid layer thickness was measured using an interferometer, and TEWL from the ocular area was measured using a Tewameter TM300 with custom-made goggles. The correlation between tear film lipid layer thickness and TEWL was evaluated. Additionally, other parameters such as TBUT, Schirmer I score, ocular surface staining, the presence and type of meibomian gland dysfunction (MGD), ocular surface disease index (OSDI), and visual analog scale (VAS) scores were evaluated. Tear film lipid layer thickness did not show a significant correlation with TEWL from the ocular area measured using a Tewameter TM300. However, tear film lipid layer thickness was significantly correlated with tear break-up time (p = 0.004) and ocular surface staining by NEI (National Eye Institute) scheme (p = 0.03). TEWL showed positive correlation with the Schirmer I score (p = 0.004). CONCLUSIONS: The tear film lipid layer affected the stability of the tear film more than the amount of TEWL in patients with short TBUT dry eye and healthy controls.