This hypothesis gains support from significant inter-parameter correlations observed between MG expressibility and meibum quality grades, MG expressibility grades and lacrimal secretion by Schirmer I test, lacrimal secretion and corneal erosion scores, tear BUT and corneal erosion scores, corneal erosion scores and SICCA OSS, and meibum quality grades and tear MMP-9 grades (Supplementary Table 1). This evidence concerns the gene MMP9 and myasthenia gravis.