In time, optometrists may not have to wait for structural or functional signs of visual field loss to appear before diagnosing primary open-angle glaucoma (POAG). According to new research, inflammatory biomarkers associated with POAG can be found in tears long before the eyes have overt signs. Evaluating the cytokine profile of the tears and the aqueous humor may one day help doctors spot glaucoma, the researchers speculate.

A research team from Madrid found an increase in cytokines in POAG patients’ tear samples. In particular, they found elevated IL-4, IL-12, IL-15, fibroblast growth factor-basic and VEGF in the tears of 27 POAG patients, as well as a decrease in MIP-1a, compared with a 29-subject healthy control group.

In the patients’ aqueous humors, IL-5, IL-12, IL-15, IFN-γ and MIP-1a were significantly higher in POAG eyes than in the healthy controls. The researchers noted a poor correlation between cytokine levels in tear and aqueous humor. Altogether, they evaluated 27 cytokines affiliated with inflammation.

The researchers suggest this work confirms the inflammatory activity of the pathology and indicates that some could be used as potential glaucoma biomarkers. 

Burgos-Blasco B, Vidal-Villegas B, Saenz-Frances F, et al. Tear and aqueous humour cytokine profile in primary open angle glaucoma. Acta Ophthalmol. February 11, 2020. [Epub ahead of print].