Clinical, optical, and behavioral characteristics of young adults classified with dry eye disease or meibomian gland dysfunction: an exploratory cross-sectional study

Dry eye disease (DED) and meibomian gland dysfunction (MGD) are prevalent, multifactorial conditions that impair quality of life and whose diagnosis relies on several invasive clinical tests. We aimed to characterize clinical, optical, blink-related, and near-work behavioral measures in young adults classified with and without DED or MGD. This prospective, cross-sectional observational study included 100 participants (85% female; mean age: 22 ± 3 years). DED was operationally classified as an OSDI score ≥ 13 together with either right-eye first-break non-invasive tear break-up time (NITBUT) < 10 s or mean right-eye fluorescein tear break-up time (TBUT) < 10 s. Visual acuity, higher order aberration, non-invasive tear break-up time and fluorescein tear break-up time, Schirmer, Oxford staining, tear meniscus height, redness, meibography, lid margin abnormality, and meibum expressibility/quality were assessed and symptom questionnaires were completed. Blink rate and inter-blink interval were derived from videos captured during standardized reading from a laptop monitor. A subset of 29 participants (93% female, mean age: 23 ± 3 years) wore a Clouclip device for one day to quantify ambient luminance and working distance. Subgroups (DED vs. non-DED; MGD vs. non-MGD) were compared using independent-samples t-tests or Mann-Whitney tests, as appropriate, and categorical outcomes were compared using chi-square or Fisher’s exact tests. Fifty-two and 40 participants met the operational DED and MGD classification criteria, respectively. After false discovery rate correction, the DED subgroup had higher lid abnormality, MGDQ and DESQ scores, poorer meibum expressibility, and more frequent ocular itching. The MGD subgroup demonstrated more corneal staining. Visual acuity, tetrafoil aberration, TBUT, blink metrics, and Clouclip-derived behavioral measures exhibited nominal exploratory differences that did not remain significant after correction. In young adults, DED and MGD were characterized primarily by differences in established clinical signs and symptom-based measures, whereas blink-related, optical, and near-work behavioral measures provided limited discriminatory value. These findings reinforce the need for multimodal assessment combining symptoms with clinical examination rather than reliance on a single non-invasive or behavior-derived measure. Larger studies are needed to determine whether such measures can contribute meaningfully to DED or MGD classification.