Measuring corneal elevation may be the most effective way to reach an early keratoconus diagnosis, a recent study found. Researchers looked at 27 patients diagnosed with unilateral keratoconus for initial change indicators of the disease in the fellow eye, which at the beginning of the study had not shown any ectatic changes. They performed receiver operating characteristic (ROC) analysis to determine which variables were best for discriminating early ectatic eyes from healthy eyes.

ROC results showed the indices of height decentration and vertical asymmetry were the most helpful measurements for detecting early changes involved in keratoconus, while the D-index took over as the most effective detection measurement once eyes progressed into early ectactic stages.

“Early stages of keratoconus are hard to diagnose and best results can be achieved by using index of height decentration and index of vertical asymmetry,” the study concluded. “Astigmatism, keratometry, and pachymetry barely change in the early stages, so these values are not as fitting as corneal elevation parameters for early diagnosis.”