An increased cup-to-disc ratio is a sign of suspected glaucoma, but an increased cup-to-disc ratio is not necessarily a sign of glaucoma. Generally, glaucoma can only be diagnosed when there is damage to the optic nerve or a visual field defect. The diagnosis of glaucoma is not made in one visit, but requires several follow-up visits before the diagnosis of glaucoma can be confirmed. In general, an increased cup-to-disc ratio is also seen in normal people. Some people are born with an increased cup-to-disc ratio but do not develop glaucoma even at an advanced age. Therefore, it depends on the shape and regularity of the rim of the disc, if it is round, without cut marks, and in accordance with clinical principles, the risk of glaucoma is usually low. This can also be combined with the results of the optic nerve oct as well as the visual field examination. If both results are normal, even if the cup-to-disc ratio is large, it is not considered a case of glaucoma.