Lipid layer thickness and tear meniscus height measurements for the differential diagnosis of evaporative dry eye subtypes.

Aim: To explore a new diagnostic index for differentiating the evaporative dry eye (EDE) subtypes by analysis of their respective clinical characteristics.

Methods: A cross-sectional study of 139 patients (139 eyes) with EDE who were enrolled and classified as obstructive meibomian gland dysfunction (MGD) (=81) and non-obstructive MGD (=58) EDE. All patients completed a Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire and were evaluated for average lipid layer thickness (LLT), tear meniscus height measurements (TMH), tear break-up time (TBUT), ocular surface staining score, Schirmer I test (SIT), lid margin abnormalities, and meibomian gland function and morphology.