Surprising astigmatism hypercorrection after corneal ring segments implantation in keratoconus treatment after 8 years of follow up.

To report a case of hypercorrection of astigmatism (Cyl) after implantation of 2 segments of short arch ring for keratoconus treatment and to describe its replacement by long arch segment. This is a case report of a patient with keratoconus and no adaptation to glasses or contact lenses, who was implanted 2 ring segments: upper nasal (155º/ 200μm) and inferior temporal (155º/ 250μm). First postoperative month: CVA = 20/ 50 (-10.