Figure 2.

Percentage of each ellipsoid zone (EZ) grade in achromatopsia (ACHM) and blue cone monochromacy (BCM). The frequency of each grade is shown within or above each bar. We observed a significant difference in the distribution of grades between ACHM and BCM, with a grade II EZ being the most common phenotype in BCM. Patients with ACHM were more than twice as likely to have a grade IV EZ than BCM, suggesting that functional short-wavelength–sensitive cones in BCM may help to prevent development of a hyporeflective zone at the fovea.