International have estimated that about 36,000 penetrating keratoplasties and only about 400 lamellar keratoplasties were performed in the United States in 1999. Lamellar keratoplasty for keratoconus can produce excellent optical results if dissection is done down to Descemet's membrane. If dissection is done more superficially, interface haze can develop. Microkeratomes cannot be used easily for such deep dissections. The risk of perforation of Descemet's still remains substantial even with air dissection.
Much work remains to optimise lamellar keratoplasty results.
A few corneal surgeons have suggested that corneal transplantation should be performed for early keratoconus as soon as contact lens wear becomes necessary for satisfactory vision. Although graft survival is excellent, graft rejection episodes are not uncommon in young keratoconus patients. Most corneal surgeons believe that keratoplasty should not be performed in keratoconus patients if the patients can still be fitted safely and comfortably and obtain good optical quality with contact lenses. Topographical analysis of the central 6 to 8mm of keratoconic corneas has permitted fitting custom-made contact lenses in patients with cones as steep as 80D while still maintaining apical clearance. Except in those extreme cases, the Rose K contact lens fitting sets and designs have facilitated fittings for most keratoconus patients and enabled many patients to avoid surgery.