DICOM PS3.3 2019c - Information Object Definitions

C.8.25.8 Lensometry Measurements Module

Table C.8.25.8-1 defines the Attributes used to capture the refractive measurements by a lensometer for spectacles. This is typically for a pair of lenses, but sometimes for just one. Sometimes a single lens is measured with an unknown laterality.

Table C.8.25.8-1. Lensometry Measurements Module Attributes

Attribute Name

Tag

Type

Attribute Description

Lens Description

(0046,0012)

2

A free text description of the lens and lens general comments.

Note

A common example is to identify the specific spectacles measured

Right Lens Sequence

(0046,0014)

1C

A Sequence that specifies measurements of a patient's right lens.

Required if the right lens is measured.

Only a single Item shall be included in this Sequence.

Note

If Right Lens Sequence (0046,0014) is present, Measurement Laterality (0024,0113), if present, will have a value of R or B as appropriate.

>Include Table C.8.25.8-2 “Lensometry Measurements Macro Attributes”

Left Lens Sequence

(0046,0015)

1C

A Sequence that specifies measurements of a patient's left lens.

Required if the left lens is measured.

Only a single Item shall be included in this Sequence.

Note

If Left Lens Sequence (0046,0015) is present, Measurement Laterality (0024,0113), if present, will have a value of L or B as appropriate.

>Include Table C.8.25.8-2 “Lensometry Measurements Macro Attributes”

Unspecified Laterality Lens Sequence

(0046,0016)

1C

A Sequence that specifies measurements of one lens of unknown laterality.

Only a single Item shall be included in this Sequence.

Shall not be included if Attribute Right Lens Sequence (0046,0014) or Left Lens Sequence (0046,0015) is present.

Required if a single lens of unknown laterality is measured.

>Include Table C.8.25.8-2 “Lensometry Measurements Macro Attributes”


Table C.8.25.8-2 describes the Attributes for the Lensometry Measurements Macro.

Table C.8.25.8-2. Lensometry Measurements Macro Attributes

Attribute Name

Tag

Type

Attribute Description

Sphere Power

(0046,0146)

1

Refractive power of the lens that is the same in all meridians, measured at distance (optical infinity), in diopters.

Include Table C.8.25.6.1-1 “Cylinder Sequence Macro Attributes”

Add Near Sequence

(0046,0100)

1C

A Sequence that specifies refractive measurements of the lens to correct for inability to focus at near while wearing the distance prescription.

Only a single Item shall be included in this Sequence.

Required if Add Near is measured in the lens.

>Add Power

(0046,0104)

1

Additional power relative to the distance correction, expressed in diopters, that allows best corrected visual acuity at the defined viewing distance.

>Viewing Distance

(0046,0106)

3

The distance, in cm, for testing visual acuity corresponding to the value of Add Power (0046,0104) in this Sequence.

Add Intermediate Sequence

(0046,0101)

1C

A Sequence that specifies refractive measurements of the lens to correct for inability to focus at intermediate distance while wearing the distance prescription.

Only a single Item shall be included in this Sequence.

Required if Add intermediate is measured in the lens.

>Add Power

(0046,0104)

1

Additional power relative to the distance correction, expressed in diopters, that allows best corrected visual acuity at the defined viewing distance.

>Viewing Distance

(0046,0106)

3

The distance, in cm, for testing visual acuity corresponding to the value of Add Power (0046,0104) in this Sequence Item.

Include Table C.8.25.6.2-1 “Prism Sequence Macro Attributes”

Lens Segment Type

(0046,0038)

3

The type of segment of a lens containing the "add" power, as described above

Enumerated Values:

PROGRESSIVE

NONPROGRESSIVE

Optical Transmittance

(0046,0040)

3

The fraction of light that passes through the measured lens optical media, in percent.

Channel Width

(0046,0042)

3

In a progressive lens, the width in mm of that portion of the lens where there is gradual or progressive increase in "add" power.

Note

See Attributes, Add Near Sequence (0046,0100) and Add Intermediate Sequence (0046,0101) for description of"add".


DICOM PS3.3 2019c - Information Object Definitions