Study of tear proteins for possible biomarker in primary open-angle glaucoma

• Published in: Journal of Clinical Ophthalmology and Research Vol. 6; no. 2; pp. 66 - 70
• Main Authors: Naik, Abhijit, Shrivastava, Saurabh, Abidi, Naheed, Yadav, Raman, Shah, Prachi, Gala, Yash
• Format: Journal Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2018
• Subjects: Biomarker; glaucoma; tear protein
• ISSN: 2320-3897
• DOI: 10.4103/jcor.jcor_17_17

Aim: We aimed to detect a possible biomarker, in tear samples, for POAG. Method: It was a case–controlled prospective study conducted over a period of 2 years. Tear samples were collected from 30 glaucoma eyes to 30 control eyes tears were collected using a sterile capillary tube and then stored in the laboratory refrigerator at 0°C for measuring the Total antioxidant activity using modified nitroblue tetrazolium method. Protein estimation by modified Lowry's method for protein quantification (1951). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis for protein profiling for various determination of molecular weight. Lipase estimation by Modified Winkler and Stuckmann method, 1979.Carbonic anhydrase-like enzyme activity using synthetic substrate. For Statistical analysis The data were entered in Microsoft Excel and analyzed using Stata Version 24. Results: The mean protein level in glaucoma patients in our study was 8.68 mg/ml, whereas the mean protein level in the control group was 8.34 mg/ml. There was no statistical difference in the mean protein level was between glaucoma and normal patients. Our study shows that the antioxidant activity was significantly lower in glaucoma patients, as compared to controls. The mean level of carbonic anhydrase-like enzymes in glaucoma patients' eyes was 12.90 IU/ml while the mean level for control eyes was 10.03 IU/ml. This is statistically significant. Glaucoma samples showed a mean lipase level of 0.05 IU/ml while controls showed a much higher value of 0.25 IU/ml. After matching the mean levels for age and sex, they were statistically significant. Conclusion: In our study, we found the levels of carbonic anhydrase, lipase, and antioxidants to be significantly different in glaucoma eyes. Each of these hold a promise of being useful as a predictive biomarker for POAG. Further studies need to be carried out to confirm all of the above findings and to thus find a sensitive and specific biomarker for glaucoma, which can be used as a screening tool in the near future.