C.8.25.16 Intraocular Lens Calculations Module

Table C.8.25.16-1 defines the Attributes used to calculate the power of an intraocular lens to be placed in a patient’s eye. This is typically done for both eyes for comparison, but may be for just one eye. Values used may be measurements acquired using the axial length measurements device, manually entered, or derived from a referenced SOP class or other data source.

Table C.8.25.16-1INTRAOCULAR LENS CALCULATIONS MODULE ATTRIBUTES

Attribute Name Tag Type Attribute Description
Intraocular Lens Calculations Right Eye Sequence (0022,1300) 1C Calculations of intraocular lens power for a patient’s right eye. One or more Items shall be included in this sequence. Required if the device calculated intraocular lens power for the right eye.
>Include 'Intraocular Lens Calculations Macro' Table C.8.25.16-2
Intraocular Lens Calculations Left Eye Sequence (0022,1310) 1C Calculations of intraocular lens power for a patient’s left eye. One or more Items shall be included in this sequence. Required if the device calculated intraocular lens power for the left eye.
>Include 'Intraocular Lens Calculations Macro' Table C.8.25.16-2

C.8.25.16.1 Intraocular Lens Calculations Module Attributes

C.8.25.16.1.1 Referenced SOP Sequence

Data in an IOL Calculations SOP Instance will frequently be gathered from other SOP instances, such as ophthalmic axial measurements SOP Instances or refractive measurements SOP Instances. If this occurs, a reference to the SOP instances is desired in attribute Referenced SOP Sequence (0008,1199).

C.8.25.16.2 Intraocular Lens Calculations Macro

Table C.8.25.16-2 describes the attributes for the Intraocular Lens Calculations Macro.

Table C.8.25.16-2 INTRAOCULAR LENS CALCULATIONS MACRO

Attribute Name Tag Type Attribute Description
Target Refraction (0022,1037) 1 The desired postoperative refractive error, in diopters.
Refractive Procedure Occurred (0022,1039) 2 Whether or not a patient has had refractive surgery. Enumerated Values: YES NO
Refractive Surgery Type Code Sequence (0022,1040) 2C Type of refractive surgery a patient has had. Zero or more Items shall be included in this sequence. Required if the value of Refractive Procedure Occurred (0022,1039) is YES.
>Include 'Code Sequence Macro' Table 8.8-1. Defined Context ID is 4234
Refractive Error Before Refractive Surgery Code Sequence (0022,1103) 2C The patient’s refractive error before any of the refractive surgeries listed in Refractive Surgery Type Code Sequence (0022,1040) were performed. Zero or one Item shall be included in this sequence. Required if the value of Refractive Procedure Occurred (0022,1039) is YES.
>Include 'Code Sequence Macro' Table 8.8-1. Defined Context ID is 4238
Corneal Size (0046,0046) 3 The horizontal diameter measurement of the cornea, in mm.
Lens Thickness Sequence (0022,1127) 3 Lens thickness value and source. Only a single Item is permitted in this sequence.
>Lens Thickness (0022,1130) 1 The value for axial length of the lens in a patient’s eye, in mm.
>Source of Lens Thickness Data Code Sequence (0022,1132) 1 Source of the value of Lens Thickness (0022,1130). Only a single Item shall be included in this sequence.
>>Include 'Code Sequence Macro' Table 8.8-1. Defined Context ID is 4240
>Referenced SOP Sequence (0008,1199) 1C SOP Instance that is relevant to the interpretation of this SOP Instance. Only a single Item shall be included in this sequence. See section C.8.25.16.1.1 for further explanation. Required if Source of Lens Thickness Data Code Sequence (0022,1132) contains an item with the value (111782, DCM, “Axial Measurements SOP Instance”).
>>Include ‘SOP Instance Reference Macro’ Table 10-11
Anterior Chamber Depth Sequence (0022,1128) 3 Anterior chamber depth value and source. Only a single Item is permitted in this sequence.
>Anterior Chamber Depth (0022,1131) 1 The value for axial length of the anterior chamber, in mm.
>Source of Anterior Chamber Depth Data Code Sequence (0022,1133) 1 Source of the value of Anterior Chamber Depth (0022,1131). Only a single Item shall be included in this sequence.
>>Include 'Code Sequence Macro' Table 8.8-1. Defined Context ID is 4240
>Referenced SOP Sequence (0008,1199) 1C SOP Instance that is relevant to the interpretation of this SOP Instance. Only a single Item shall be included in this sequence. See section C.8.25.16.1.1 for further explanation. Required if Source of Anterior Chamber Depth Data Code Sequence (0022,1133) contains an item with the value (111782, DCM, “Axial Measurements SOP Instance”).
>>Include ‘SOP Instance Reference Macro’ Table 10-11
Refractive State Sequence (0022,001B) 2 Refractive state of the imaged eye at the time of acquisition. Zero or one Item shall be included in this sequence.
>Spherical Lens Power (0022,0007) 1 Sphere value in diopters.
>Cylinder Lens Power (0022,0008) 1 Cylinder value in diopters.
>Cylinder Axis (0022,0009) 1 Axis value in degrees.
>Source of Refractive Measurements Sequence (0022,1134) 1 Refractive measurements source. Only a single Item shall be included in this sequence.
>>Source of Refractive Measurements Code Sequence (0022,1135) 1 Source of values in Refractive State Sequence (0022,101B). Only a single Item shall be included in this sequence.
>>>Include 'Code Sequence Macro' Table 8.8-1. Defined Context ID is 4240
>>Referenced SOP Sequence (0008,1199) 1C SOP Instances that are relevant to the interpretation of this SOP Instance. One or more items shall be included in this sequence. See section C.8.25.16.1.1 for further explanation. Required if Source of Refractive Measurements Code Sequence (0022,1135) contains an item with the value (111783, DCM, “Refractive Measurements SOP Instance”).
>>>Include ‘SOP Instance Reference Macro’ Table 10-11
Include ‘Keratometry Macro’ Table C.8.25.16-3
IOL Formula Code Sequence (0022,1028) 1 Formula used to calculate IOL power. Only a single Item shall be included in this sequence.
>Include 'Code Sequence Macro' Table 8.8-1. Defined Context ID is 4236
IOL Formula Detail (0022,1029) 3 A free form text description of the of the IOL Formula Code Sequence (0022,1028) (e.g. a reference to the mathematical equation).
Include ‘IOL Ophthalmic Axial Length Macro’ Table C.8.25.16-4
Include ‘Calculated IOL Macro’ Table C.8.25.16-5

C.8.25.16.3 Keratometry Macro

Table C.8.25.16-3 describes the attributes for the Keratometry Macro.

Table C.8.25.16-3 KERATOMETRY MACRO

Attribute Name Tag Type Attribute Description
Steep Keratometric Axis Sequence (0046,0074) 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.
>Keratometric Power (0046,0076) 2 The refractive power of the cornea at the principal meridians, measured in diopters.
>Keratometric Axis (0046,0077) 2 The meridian where the keratometric radius of curvature or power is measured, in degrees.
Flat Keratometric Axis Sequence (0046,0080) 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.
>Keratometric Power (0046,0076) 2 The refractive power of the cornea at the principal meridians, measured in diopters.
>Keratometric Axis (0046,0077) 2 The meridian where the keratometric radius of curvature or power is measured, in degrees.
Keratometry Measurement Type Code Sequence (0022,1096) 2 Descriptors relevant to keratometry data. Zero or one Item shall be included in this sequence.
>Include 'Code Sequence Macro' Table 8.8-1. Defined Context ID is 4235
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.

C.8.25.16.4 IOL Ophthalmic Axial Length Macro

Table C.8.25.16-4 describes the attributes for the IOL Ophthalmic Axial Length Macro.

Table C.8.25.16-4 IOL OPHTHALMIC AXIAL LENGTH MACRO

Attribute Name Tag Type Attribute Description
Ophthalmic Axial Length Sequence (0022,1012) 1 Axial length value and source that was used in calculation of IOL power. Only a single Item shall be included in this sequence.
>Ophthalmic Axial Length (0022,1019) 1 The axial length of a patient’s eye, in mm, that was used in calculation of IOL power.
>Ophthalmic Axial Length Selection Method Code Sequence (0022,1250) 1 Method used to select the value recorded in Ophthalmic Axial Length (0022,1019). Only a single Item shall be included in this sequence.
>>Include 'Code Sequence Macro' Table 8.8-1. Defined Context ID is 4241
>Source of Ophthalmic Axial Length Code Sequence (0022,1035) 1 Source of the value of Ophthalmic Axial Length (0022,1019). Only a single Item shall be included in this sequence.
>>Include 'Code Sequence Macro' Table 8.8-1. Defined Context ID is 4240
>Referenced SOP Sequence (0008,1199) 1C SOP Instances that are relevant to the interpretation of this SOP Instance. One or more items shall be included in this sequence. See section C.8.25.16.1.1 for further explanation. Required if Source of Ophthalmic Axial Length Code Sequence (0022,1035) contains an item with the value (111782, DCM, “Axial Measurements SOP Instance”).
>>Include ‘SOP Instance Reference Macro’ Table 10-11
>Ophthalmic Ultrasound Method Code Sequence (0022,1044) 1C Method used for obtaining axial measurements of the eye. Required if Ophthalmic Axial Measurements Device Type (0022,1009) is ULTRASOUND. Only a single Item shall be included in this sequence.
>>Include 'Code Sequence Macro' Table 8.8-1. Defined Context ID is 4230

C.8.25.16.5 Calculated IOL Macro

Table C.8.25.16-5 describes the attributes for the Calculated IOL Macro.

Table C.8.25.16-5 CALCULATED IOL MACRO

Attribute Name Tag Type Attribute Description
IOL Manufacturer (0022,1093) 1 Name of the manufacturer that produced the lens.
Implant Name (0022,1095) 1 The (product) name of the lens.
Lens Constant Sequence (0022,1092) 1 Constants used in calculation of intraocular lens power. These constants are a characteristic of the model of intraocular lens being considered for use in cataract surgery. One or more Items shall be included in this sequence.
>Concept Name Code Sequence (0040,A043) 1 Constant type used in calculation of intraocular lens power. Only a single Item shall be included in this sequence.
>>Include 'Code Sequence Macro' Table 8.8-1. Defined Context ID is 4237
>Numeric Value (0040,A30A) 1 The value of the constant used.
IOL Power Sequence (0022,1090) 1 Information needed to select the intraocular lens power for cataract surgery. One or more Items shall be included in this sequence.
>IOL Power (0022,1053) 1 The intraocular lens power, in diopters.
>Predicted Refractive Error (0022,1054) 1 The predicted postoperative refractive error (i.e. amount of near or far sightedness), in diopters.
>Implant Part Number (0022,1097) 2 The (product) identifier of the lens.
IOL Power for Exact Emmetropia (0022,1121) 2 The IOL power that would be required to achieve exact emmetropia, or no need for glasses at distance after surgery, in diopters.
IOL Power for Exact Target Refraction (0022,1122) 2 The IOL power that would be required to exactly achieve the Target Refraction (0022,1037), in diopters.

C.8.25.16.6 Ophthalmic Axial Measurements Quality Image SOP Instance Reference Macro

Table C.8.25.16-6 describes the attributes for the Ophthalmic Axial Measurements Quality Image SOP Instance Reference Macro

Table C.8.25.16-6 OPHTHALMIC AXIAL MEASUREMENTS QUALITY IMAGE SOP INSTANCE REFERENCE MACRO

Attribute Name Tag Type Attribute Description
Referenced SOP Class UID (0008,1150) 1 Uniquely identifies the referenced SOP Class. Enumerated Values: “1.2.840.10008.5.1.4.1.1.7.2” = Multi-frame Grayscale Byte Secondary Capture Image Storage “1.2.840.10008.5.1.4.1.1.7.4” = Multi-frame True Color Secondary Capture Image Storage
Referenced SOP Instance UID (0008,1155) 1 Uniquely identifies the referenced SOP Instance.
Referenced Frame Number (0008,1160) 1 Identifies the frame number within the Referenced SOP Instance to which the reference applies. The first frame shall be denoted as frame number 1. Only a single value shall exist. Note: This Attribute is a multi-value field but for this Macro it can only contain one value.