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Purpose Primary open angle glaucoma (POAG) is a leading cause of irreversible blindness on a global level. Researchers have yet to specify the exact mechanisms of POAG; the respective relationships between POAG and elevated intraocular pressure (IOP), as well as optic neuropathy, remain particularly unclear. It is known, however, that the expression profile for some proteins in the aqueous humor (AH) changes in some diseases, and that AH changes play important roles in elevated IOP. To identify the possible roles of these AH proteins in POAG, a proteomic analysis of the AH compositions of POAG patients’ eyes was performed and compared with those derived from paired, non-POAG cataract (control) eyes. Methods We used Bradford’s method to determine total protein concentration in AH, and analyzed separation profiles via two-dimensional (2D) gel electrophoresis. We used silver stain to determine gel proteins, and analyzed separation profiles to assess spot density differences between POAG and non-POAG patients. These gel spots were isolated and identified via mass spectrometry. Prostaglandin H2 D-isomerase (PGDS) in AH were analyzed by western Blotting. Results There was no significant difference between the total protein concentration in AH of POAG patients and that in AH of non-POAG patients. A total of seven spots were increased in 2D gels from POAG patients. The spots were derived from PGDS, caspase 14 precursor, transthyretin, cystain C, albumin precursor, and tranferrin. And PGDS in AH from patients was more than from controls. Conclusions The protein composition in AH was significantly different in POAG patients versus non-POAG patients. The identified proteins could be a potential biomarker for POAG and may play a role in the mechanisms of elevated IOP and optic neuropathy in POAG.

Purpose The mechanism of axial elongation in the myopic eyeball remains to be elucidated. It is known that the expression profile for some proteins in the aqueous humor (AH) changes in some diseases. Accordingly, determinations of these AH proteins may serve to understand their potential role in this pathogenesis. To identify the possible mechanism in myopia development, a proteomic analysis of the AH composition from high myopic eyes (patients) was performed and compared with that of the AH composition from non-myopic cataract eyes (controls). Methods Total protein concentration in AH was determined by the Bradford method, and separation profiles were analyzed by two-dimensional (2D) gel electrophoresis. Protein in gel was determined by silver stain, and the separation profiles were analyzed to assess spot density changes between myopia and non-myopia patients. These spots in gel were isolated and identified by mass spectrometry. Results The total protein concentration in AH with high myopia was significantly greater than that of non-myopia. A total of six spots were significantly increased in 2D gels from high myopia. The spots were derived from albumin, transthyretin, and a vitamin D-binding protein. Conclusions The protein composition in AH was significantly different between myopia and non-myopia. The identified proteins could be a potential biomarker for high myopia development and may play a role in the mechanisms of myopia ocular axial elongation.