(FIGURE 1) Significant progression of keratoconus over 3 months (Images courtesy of William B. Trattler, MD)

(FIGURE 2) A 14-year-old girl with unilateral keratoconus. Since her other eye had 20/20 UCVA, the patient held off on having treatment. The patient returned 18 months later with severe progression of her keratoconus. (Images courtesy of William B. Trattler, MD)

(FIGURE 3) In some cases, patients may elect to hold off on the CXL procedure. When these patients return for follow-up exams, repeat topography or tomography can be performed, and the maps can be compared to determine whether the corneal shape is stable or progressing. (Images courtesy of William B. Trattler, MD)