Newer technologies, improved diagnostics altering treatment of corneal ectasia

Corneal ectasia is an important corneal pathology, and like so many other diseases, its diagnosis and treatment are currently evolving rapidly. Corneal ectasia includes keratoconus, pellucid marginal degeneration, posterior keratoconus and post-laser refractive surgery ectasia. Estimates of the number of patients with this diagnosis vary widely. The classic prevalence number is 1:2,000, meaning that there are about 180,000 patients with keratoconus in the U.S. I think this number is low, and some sources have suggested a prevalence as high as 1:400, which would increase the number to 900,000. If we include the so-called forme fruste keratoconus or keratoconus suspect, the number may be higher yet.Large LASIK centers and practices report that at least 10% of patients are denied laser refractive surgery because of a cornea that is too thin or has an atypical topography that makes the surgeon nervous. Because only myopes and hyperopes are usually seen at these centers, the number might be smaller for the overall population, but in my opinion, as much as 1% to 2% of the population may fit into the forme fruste keratoconus or keratoconus suspect category. That moves the number of at-risk patients in the U.S. up to 3.6 million to 7.2 million. This makes the patient with frank corneal ectasia or risk factors for ectasia more common than classically taught, and as treatment options become safer and more readily available, clinicians will need to decide which of these patients deserve treatment with soon-to-be FDA-approved (we hope) approaches such as corneal collagen cross-linking (CXL).