Diagnostic accuracy of keratoconus using anterior segment optical coherence tomography

The aims of the present study are i) to evaluate the diagnostic accuracy of RTVue non-contact, high-resolution spectral domain optical coherence tomography (RTVue OCT) in identifying keratoconic eyes from a group of healthy eyes; and ii) to examine how the severity of disease affects diagnostic accuracy. Corneal thickness measurements were performed using the RTVue OCT on 58 eyes of 29 individuals (10 males, 19 females). Of them, 28 eyes were deemed to be keratoconic, and 30 eyes healthy on the basis of clinical findings. Sensitivity, specificity and receiver operating characteristic (ROC) area was calculated overall and by grouping eyes by severity of disease. On the whole, the ROC area was highest for the parameters minimum thickness and difference between minimum and maximum thickness of cornea (0.98). The ROC area for the parameters difference in superior nasal and inferior temporal thickness and difference in superior and inferior thickness was 0.81 and 0.77, respectively. The ROC area in identifying eyes with keratoconus varied as a function of severity of disease. From our analysis we can conclude that the RTVue OCT provides excellent diagnostic ability in identifying moderate to advanced cases of keratoconus.