Iatrogenic keratoconus as a complication of radial keratotomy

A 47-year-old man with a family history of keratoconus had uneventful bilateral radial keratotomy (RK) with astigmatic keratotomy (AK) enhancements 12 years earlier. He noticed a gradual onset of blurry vision with progressively increasing myopic shift. Visual acuity remained poor even with spectacles or soft contact lenses. Slitlamp examination revealed 16 well-healed RK scars and 2 AK scars with marked corneal steepening inferiorly in an area of astigmatic enhancement in the left eye but an otherwise normal fellow eye with 16 well-healed RK scars. He subsequently had penetrating keratoplasty for decreased vision not correctable by rigid gas-permeable contact lenses. Microscopic examination of the corneal button showed findings consistent with keratoconus. This case represents the first documented incidence of corneal ectasia as a complication of primary RK.