The US food and Drug Administration (FDA) originally approved INTACS prescription inserts in April 1999 for the correction of low levels of nearsightedness (-1.00 to -3.00 diopters). Additional clinical data have shown that INTACS are safe for the treatment of keratoconus, in July 2004, FDA approved INTACS inserts for the treatment of keratoconus as a Humanitarian Use Device (FDA approval letter attached). The statute and the implementing regulation of FDA (21 CFR 814.124 (aj) require IRB review and approval before a HUD is used.INTACS prescription inserts are composed of two clear segments, each having an arc length of 150°, they are manufactured form a biomedical material called polymethylmethacrylate (PMMA) and are available in three thicknesses. Two INTACS inserts ranging from 0.250mm to 0.350mm may be implanted depending on the orientation of the cone and the amount of myopia and astigmatism to be reduced.