The First Asymmetric Ring AS6-300/150° Implantation in Keratoconus

Refraction topo (axial power map) BCVA: 5/10 with (-3.50; 65) 
Refraction on TOPO (Fourier Index asymmetry) 
Refrac: BCVA (-3.50 [A]85°) = 1 elt of 8/10

Asymmetric corneal ring segment

Apical diameter: 6,80 mm
Base width: 800µ
Arc length: 150°
Thickness: 250-350-250

Tunnel parameters

Interior diameter: 5,95 mm
Exterior diameter: 7,35 mm
Interior depth = exterior depth: 
80% thickness at implantation site

My conclusions

• The Asymmetric ring AS6-150° 250/350/250 is effective in flattening the cornea.
• The flattening is more important at the top of the ectasia where the ring is thickest (350).
• The flattening gradually decreases at the periphery of the ectasia, where the two ends of the ring are thin (250µ).
• The centering of the asymmetric ring on the axis of the Fourier axial asymmetry gave a good functional and topographic results.

Effectiveness on axial asymmetry and therefore on aberrations (Coma), in addition to effectiveness on the SE.