OPN4 and glaucoma: The ROC analysis demonstrated that the superonasal PIPR has a fair diagnostic accuracy89 (AUC = 0.74, p = 0.03) to discriminate melanopsin dysfunction in glaucoma suspects from healthy eyes and excellent diagnostic accuracy to discriminate early glaucoma (AUC = 0.94, p < 0.0001) and late glaucoma (AUC = 0.97, p < 0.0001) from healthy eyes (Fig. 9).