Figure 3.

Examples of OCT images demonstrating the significant heterogeneity of grade II ellipsoid zone (EZ) in blue cone monochromacy (BCM). MP_10097 and JC_11237 are fairly typical examples of grade II, with both patients having disruption that extends the full height of the EZ, although MP_10097 has a focal disruption and JC_11237 shows broader mottling of the EZ. There was some debate as to whether MM_0186 was grade I or II as, although there was a small focal disruption of the EZ just nasal of the foveal center, it did not extend the full height of the band. It was decided that any altered reflectivity constituted “EZ disruption.” JC_10558 has a small pocket of hyporeflectivity, which may represent the short-wavelength–sensitive cone-free zone. There was contention between graders as to whether JC_0184 was grade II or IV, as the region of hyporeflectivity is small, and it was debatable as to whether the ELM was bowing upward (which would indicate grade IV) or whether it had a normal contour (indicating grade II). Although BCM patients often lack the foveal bulge, it was decided that JC_0184 had a normal ELM contour. MP_10100 had abnormal hyperreflectivity between the EZ and ELM, which gives the impression of a dipping ELM (perhaps indicating grade III), but it was decided that the ELM was intact, leaving the source of the abnormal hyperreflectivity unclear.