A study of aqueous humour proteins in patients of primary open angle glaucoma

Aims: To investigate the changes in the protein composition of aqueous humour in primary open angle glaucoma patients and non-glaucomatous subjects. Patients and Methods: Case control study was conducted at a university hospital to compare the protein profile of aqueous humour obtained from patients of primary open angle glaucoma with those of non glaucomatous subjects. Protein concentration of the aqueous humour samples collected from both glaucomatous and non-glaucomatous patients at the time of surgery was estimated by the Bradford protein assay method. Sodium dodecylsulfate polyacrylamide gel electrophoresis of the samples was also performed. Results: Geometric mean of protein concentration of the samples was 55.73 mg/dl (range: 31-72) in the test group and 46.46 mg/dl (range: 27-65) in the control group and a statistically significant (p ≤= 0.001) difference in protein concentration of aqueous humour between the two groups was observed. Electrophoretic study revealed differences in the aqueous protein composition of the two groups. The glaucomatous group exhibited protein bands of 10 kDa, 20 kDa, 30 kDa, 50 kDa, 60 kDa, 70 kDa, and 90 kDa while the control subjects demonstrated bands of 6 kDa, 10 kDa, 30 kDa, 70 kDa, 90 kDa. Interestingly, almost all the proteins detected in this study corresponded to the molecular weights of heat shock proteins. Conclusions: Primary open angle glaucoma patients differed in protein compositions and had higher concentration of aqueous humour proteins than non glaucomatous patients.