Is primary open angle glaucoma caused by small proteins?

Primary open angle glaucoma is a disease which is characterized by a decreased facility of outflow of aqueous humor from the anterior segment of the eye. Analyses by gel exclusion chromatography of the aqueous humor of normal monkeys have shown that the proteins in this fluid range in size from approximately 40-200 kilodaltons. Although small proteins and peptides are seen in the aqueous humor by SDS gel electrophoresis, these smaller proteins appear to elute by column chromatography with the albumin peak. In the outflow of the aqueous humor, the trabecular meshwork may be an efficient sieve for proteins of intermediate size, but this tissue may be obstructed if the proteins present become too large or too small as a result of other disease processes in the eye. Primary open angle glaucoma may be the result of the inability of the trabecular meshwork to filter small proteins and polypeptides efficiently.