Baptista PM, Marques JH, Neves MM, et al. - Researchers conducted this retrospective observational study to characterise the anatomical and functional outcomes of the implantation of asymmetric thickness intracorneal ring segments (AS-ICRS) in eyes with keratoconus and asymmetric/irregular astigmatism (type 2 – Duck – and type 3 – Snowman – phenotypes, Fernandez-Vega/Alfonso morphologic Keratoconus classification). The sample consisted of 19 consecutive patients (21 eyes) with keratoconus who underwent manual implantation of the Keraring Asymmetric ICRS (AS). Keraring Asymmetric ICRS implantation in keratoconus with asymmetric/irregular astigmatism allowed many clinical, topographic and aberrometric parameters to be improved, with clinical effectiveness and safety, with a tendency to be more effective in type 2 cones.