The E-R Model in Section A.1.2 depicts those components of the DICOM Information Model that directly reference the Ophthalmic Photography 8-Bit Image IOD, with exception of the VOI LUT, and Modality LUT entities, which are not used. Table A.41-1 specifies the Modules of the Ophthalmic Photography 8 Bit Image IOD.
The Curve Module (Retired) was previously include in the list of Modules that shall not be present, but has been retired from DICOM. It is still not permitted to be present. See PS3.3-2004.