Keratoconus: Current perspectives

Keratoconus is a corneal thinning disorder in which the inferior paracentral cornea thins and protrudes forwards. The onset is usually during the second decade. Blurred vision and frequent changes of spectacle power are the common presenting symptoms. In addition to heredity, there seems to an association of eye rubbing and development of keratoconus. Slit lamp examination and topographic evaluation helps to us detect early keratoconus, assess severity of keratoconus and decide management options. Keratoconus seems to be associated with other eye conditions like eye allergy, retinitits pigmentosa, Leber’s optic atrophy and also with systemic conditions like Marfan’s syndrome and Ehler Danlos syndrome. Rigid gas permeable (RGP) lenses are recomended contact lenses in keratoconus patients with mild to moderate astigmatism. Piggy back contact lens, softperm lens and scleral lens RGP lenses can be used in large ectasia. Implatation of PMMA (polymethylmethacrylate) intracorneal rings into the paracentral cornea has been found successful to reduce the spherical power and astigmatism. Since endothelium is relatively healthy, deep anterior lamellar keratoplasty is becoming the surgery of choice for patients who are not having good vision with contact lens or are not able to tolerate contact lens. Full thickness corneal transplantation (PK) is suggested in patients with dense central scar which is deeper and involving the Descemet’s membrane. Toric implantable contact lens (ICL) is useful if the keratoconus is stable or is the progression is arrested by doing collagen cross- linking or the irregular astigmatism is reduced following implantation of intracorneal ring. Keywords: keratoconus; keratoplasy; management; DALK surgery