Skip to main content

Table 1 Evidence for assessing the suitability of tear proteins for clinical use

From: Practical issues concerning tear protein assays in dry eye

Class of tear protein Potential clinical marker Human tear levels show consistent dysregulation Human tear levels linked to clinical signs/symptoms of dry eye Change with treatment or severity of dry eye? Biological function in dry eye pathology known?
Lacrimal protein Lactoferrin ++++ [21]-[25] +++ [26],[27] + [28] ++ [29]
Protease MMP-9 +++ [30]-[32] +++ [11] +++ [33] +++ [34]-[42]
Lacrimal protein Lysozyme ++ [21],[43]-[45] + [43] 0 0
Mucins MUC5AC +++ [46],[47] + [48] 0 ++ [49],[50]
Lipid binding protein Lipocalin ++ [45],[51] + [52] ++ [52] + [53]-[55]
Interleukines IL-6 +++ [10],[31],[56],[57] + [58] ++ [58] + [59]-[61]
Chemokine IL-8 ++ [10],[57],[62],[63] ++ [62] 0 ++ [61],[64]
Keratinisation-related S100A8/9 +++ [5],[13],[14],[65] +++ [5],[13] 0 + [66],[67]
Epithelial health EGF ++ [57],[64],[68] + [69] 0 ++ [70]
Neurotrophic health NGF +++ [71],[72] ++ [71],[73],[74] ++ [73],[74] ++ [75],[76]
  1. ++++ strong evidence.
  2. +++ good evidence.
  3. ++ modest evidence, some uncertainties about implication.
  4. + some evidence but studies may have conflicting results.
  5. 0 no clear evidence.