DICOM PS3.3 2020c - Information Object Definitions
C.8.25.16.8 Cornea Measurement Macro

Table C.8.25.16-8 specifies and describes the attributes for the Cornea Measurement Macro used in IOL calculation.

Table C.8.25.16-8. Cornea Measurement Macro Attributes

Attribute Name

Tag

Type

Attribute Description

Steep Corneal Axis Sequence

(0046,0112)

1

Steepest meridian as defined by the greatest power of curvature and shortest radius of curvature.

Only a single Item shall be included in this Sequence.

>Radius of Curvature

(0046,0075)

1

The radius of curvature of the principal meridians of the cornea, measured in mm.

>Corneal Power

(0046,0114)

2

The refractive power of the cornea at the principal meridians, measured in diopters.

>Corneal Axis

(0046,0115)

2

The meridian where the radius of curvature or corneal power is measured, in degrees.

Flat Corneal Axis Sequence

(0046,0113)

1

Flattest meridian as defined by the least power of curvature and longest radius of curvature.

Only a single Item shall be included in this Sequence.

>Radius of Curvature

(0046,0075)

1

The radius of curvature of the principal meridians of the cornea, measured in mm.

>Corneal Power

(0046,0114)

2

The refractive power of the cornea at the principal meridians, measured in diopters.

>Corneal Axis

(0046,0115)

2

The meridian where the radius of curvature or corneal power is measured, in degrees.

Cornea Measurement Method Code Sequence

(0046,0116)

1

Method of the cornea measurement.

Only a single Item shall be included in this Sequence.

>>Include Table 8.8-1 “Code Sequence Macro Attributes”

DCID 4242 “Cornea Measurement Method Descriptors”

Keratometer Index

(0022,1033)

2

The translation factor specific to each keratometer that derives a number for power from the measured radius of curvature of the cornea.

Refractive Index of Cornea

(0046,0117)

1C

The refractive translation factor specific for the cornea when deriving a number of power from the measured radius of curvature of the posterior surface of cornea.

Required if Cornea Measurement Type Code Sequence (0046,0116) contains an item with the value (DCM, 111759, "Posterior Cornea Surface Measurement").

Refractive Index of Aqueous Humor

(0046,0118)

1C

The refractive translation factor specific for the aqueous humor when deriving a number of power from the measured radius of curvature of the posterior surface of cornea.

Required if Cornea Measurement Type Code Sequence (0046,0116) contains an item with the value (DCM, 111759, "Posterior Cornea Surface Measurement").


DICOM PS3.3 2020c - Information Object Definitions