Exfoliation glaucoma (XFG) is the most common identifiable cause of open-angle glaucoma worldwide, and results from the accumulation of extracellular fibrillary material (XFM) within the trabecular meshwork and the Schlemm canal leading to increased intraocular pressure and potential blindness. Immunohistochemical and mass spectrometry analyses have revealed that XFM is a highly glycosylated proteinaceous complex that is extremely resistant to degradation both within the body and under experimental conditions. The protein core contains a wide variety of proteins, including basement membrane proteins, elastic fiber proteins, latent TGFβ proteins, metalloproteinases, chaperone proteins, complement proteins, lysyl oxidase-like 1 (LOXL1), and apolipoprotein E (ApoE). This supplemental section identifies the advances in knowledge and current understanding of the components within XFM with a specific focus on the most recent work defining proteins within XFM and to pose several biological questions that remain unanswered.