<prompt> Corneal dystrophies are usuallyPrimarily unilateralPrimarily bilateralPrimarily unilateral without systemic diseasePrimarily bilateral with systemic disease  <response>: A corneal dystrophy is classically bilateral, progressive, and isolated to the cornea. The disorder is inherited, characteristically in a dominant fashion, and often appears clinically to involve only one layer of the cornea ...Yanoff 