C.8.25.6 General Ophthalmic Refractive Macros

C.8.25.6.1 Cylinder Sequence Macro

Table C.8.25.6.1-1 describes the attributes for the Cylinder Sequence Macro

Table C.8.25.6.1-1CYLINDER SEQUENCE MACRO

Attribute Name Tag Type Attribute Description
Cylinder Sequence (0046,0018) 1C A sequence that specifies lens measurements to correct for astigmatism or measurements of an eye that has astigmatism. Required if astigmatic correction or astigmatism is measured. Only a single item shall be included in this sequence. Note: When astigmatism is present the power is NOT the same in all meridians, but has its minimum and maximum power in meridians separated by 90 degrees.
>Cylinder Power (0046,0147) 1 The power that is present at the power meridian (90 degrees from the axis), in diopters.
>Cylinder Axis (0022,0009) 1 The meridian, defined in degrees, that is 90 degrees from the power meridian.

C.8.25.6.2 Prism Sequence Macro

Table C.8.25.6.2-1 describes the attributes for the Prism Sequence Macro

Table C.8.25.6.2-1PRISM SEQUENCE MACRO

Attribute Name Tag Type Attribute Description
Prism Sequence (0046,0028) 1C A sequence that specifies prism that is measured in a lens, or that is required to correct for a patient’s ocular misalignment. Required if prism is measured in the lens or if this part of a refraction is done for a patient. Only a single item shall be included in this sequence. Note: A prism is a wedge shaped lens that deviates light toward the base and shifts the apparent image toward its apex.
>Horizontal Prism Power (0046,0030) 1 The power of a prism to bend light in the horizontal direction, in prism diopters.
>Horizontal Prism Base (0046,0032) 1 Direction of the base of the measured prism -- either in (toward the nose), or out (away from the nose) Enumerated Value: IN OUT
>Vertical Prism Power (0046,0034) 1 The power of a prism to bend light in the vertical direction, in prism diopters.
>Vertical Prism Base (0046,0036) 1 Direction of the base of the measured prism -- either up, or down. Enumerated Value: UP DOWN