Current surgical options for keratoconus.

The treatment of keratoconus is partly dependent on the severity of the disease process. When contact lenses fail because the patient is intolerant or they do not provide sufficient acuity to meet the patient's needs, penetrating keratoplasty is the usual surgical modality for adequate visual rehabilitation. Keratoconus is considered a contraindication to incisional refractive surgery such as radial keratotomy and laser in situ keratomileusis because of the corneal instability conferred by these procedures. When the cornea is transparent, intrastromal corneal ring implantation is a refractive modality that may improve visual function and, in select keratoconus patients, obviate the need for corneal transplantation.