Identification of diagnostic and prognostic biomarkers in dry eye disease in primary open‐angle glaucoma: A cross‐sectional case‐control study

Aims/Purpose: To integrate clinical and molecular data that allow us to identify diagnostic and prognostic biomarkers of dry eye disease (DED) in primary open‐angle glaucoma (POAG). Methods: A cross‐sectional case‐control study consisting of 182 participants of both sexes, was done. Volunteers were classified into 4 groups: healthy controls (CG; n = 50), DED group (n = 42), POAG group (PG; n = 44), and DED+POAG (n = 46). All participants underwent a complete and systematic medical history, filled out the questionnaires, and were subjected to ophthalmologic examination. Reflex tear samples were collected and subsequently processed using enzyme‐linked immunosorbent assay (ELISA) to quantify the levels of interleukins (IL) ‐1β and ‐18. Statistical analysis was performed with the SPSS 28.0 program. Results: Mean age of the study participants was 60+15 years, with a total of 56 males (31%) and 126 females (69%). The use of preservative‐containing eye drops was observed in 13% of the POAG patients, and 21% of the DED+POAG group. Clinical data [Schirmer test, tear break‐up time (TBUT), tear meniscus height (TMH) measured by optical coherence tomography (OCT)], and the tear expression of IL‐1β and IL‐18 were significantly different between groups. According to the ocular surface disease index (OSDI) questionnaire, dry eyes were more severe (OSDI=42) and the IL‐1β and IL‐18 tear levels were significantly higher in 37% of the DED+POAG patients. Conclusions: We suggest that assessment of TMH, OSDI, and the tear expression of IL‐1β and IL‐18 can be potential biomarkers for identifying patients at risk of DED in the POAG subgroup undergoing treatment with antihypertensive eye drops.