Qualitative analysis and clinical implications of lipid layer thickness variability: A retrospective, cross-sectional study.

Abstract

Meibomian gland (MG) dysfunction impairs the tear film lipid layer, which is critical for preventing aqueous evaporation and maintaining tear film stability. While a LipiView® II-reported mean lipid layer thickness (LLT) of ≥100 nm indicates a high- or ceiling-range device output rather than a calibrated absolute LLT, mean LLT alone may overlook clinically relevant information about the dynamic behavior of the tear film. This study aimed to evaluate whether qualitative variability in 20-s LipiView® II dynamic LLT traces is associated with MG morphology and ocular surface findings in eyes with device-reported high-range LLT values. In this retrospective, cross-sectional study, we analyzed 20-s dynamic LipiView® II recordings from eyes that were initially measured to have a mean LLT of ≥100 nm. Two masked observers classified LLT pattern variability as high or low based on predefined criteria. Clinical and demographic differences between the high- and low-variability groups were assessed statistically. Out of 85 eyes, 58 (68.2%) and 27 (31.8%) exhibited high- and low-variability, respectively. The high-variability group demonstrated markedly elevated meiboscores compared to the low-variability group, indicating a greater degree of MG dropouts (p = 0.042). Besides elevated meiboscores, patients in the high-variability group suffered from substantially worse dry eye disease (DED) symptoms, a trend toward higher corneal and conjunctival staining scores, and significantly increased blinking frequency (p < 0.05). Qualitative evaluation of LLT revealed increased meiboscores, greater severity of DED symptoms, and increased blinking frequency even in eyes with device-reported high-range mean LLT. LLT pattern analysis may warrant evaluation as an adjunctive approach for the early detection and targeted management of MG dysfunction-related evaporative DED.