Table 2.

Technical specifications of commonly used intracorneal ring segments (ICRS).

Model	Arc length (°)	Thickness (µm)	Cross-section	Optical zone (mm)	Inner diameter (mm)	Outer diameter (mm)
Intacs	150, 210	210, 230, 250–450 (50 µm steps)	Hexagonal	7	6.77	8.1
Intacs SK	90, 130, 150	210, 250–500 (50 µm steps)	Elliptical	6	6	7
Keraring	90, 120, 150, 160, 210, 340, 355	150–350 (50 µm steps)	Triangular	5.0, 5.5, 6.0	5	6
Ferrara	90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 210, 320	150–350 (50 µm steps)	Triangular	5.0, 6.0	4.4	5.6
Myoring	360	200–320	Triangular	No data	5.00–8.00	6.00–9.00