Dorcas K. Tsang
Frank Spors
Jie Shen
Lance E. McNaughton
Donald J. Egan

Abstract Keratoconus is a progressive corneal disease characterized by bilateral yet usually asymmetric thinning of the cornea with an onset typically in teenage years. While it often presents as an isolated condition, keratoconus may also be associated with many systemic and/or ocular diseases, such as connective tissue and chromosomal disorders. Its association with nystagmus has been described in Leber’s congenital amaurosis, where patients also exhibit abnormal pupillary responses, early-onset retinal dystrophy, mental developmental delays, and eventual blindness. The case described here, however, was a high-functioning teenager with keratoconus and infantile nystagmus, and oscillopsia on left gaze and a compensatory head turn to the patient’s left. The initial distance visual acuities of ۲۰/۶۰ and ۲۰/۱۵۰ in the right and left eye, respectively improved to ۲۰/۲۵ and ۲۰/۴۰ by the use of corneal rigid gas permeable contact lenses. In addition, the patient’s neck strain and overall gait were eased by yoked prism spectacles.