ISO/TS 22218-1:2023
(Main)Health informatics — Ophthalmic examination device data — Part 1: General examination devices
Health informatics — Ophthalmic examination device data — Part 1: General examination devices
This document specifies the measurement data output formats for devices used in general ophthalmic examiniations, including the following modalities: — Refractometer (REF) Refraction — Keratometer (KM) Corneal curvature — Tonometer (TM) Intraocular pressure — Lensmeter (LM) Spectacle lens power — Phoroptor (PHOR) Visual acuity This document only addresses text-based device reporting of ophthalmic examination device data (OEDD). Images generated as needed during an ophthalmic examination are outside the scope of this document.
Informatique de santé — Données relatives aux dispositifs d'examen ophtalmique — Partie 1: Dispositifs pour les examens généraux
General Information
Standards Content (Sample)
TECHNICAL ISO/TS
SPECIFICATION 22218-1
First edition
2023-01
Health informatics — Ophthalmic
examination device data —
Part 1:
General examination devices
Informatique de santé — Données relatives aux dispositifs d'examen
ophtalmique —
Partie 1: Dispositifs pour les examens généraux
Reference number
ISO/TS 22218-1:2023(E)
© ISO 2023
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ISO/TS 22218-1:2023(E)
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ISO/TS 22218-1:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Specifications . 4
4.1 General . 4
4.2 deviceCDA and persistent examination reports . 4
4.3 Data classification constitution in the file . 5
4.4 OEDD structure . 6
4.4.1 General . 6
4.4.2 Data classifications . 7
4.4.3 Attribute value and classification . 7
4.4.4 Handling of common data . 7
4.4.5 Handling of ophthalmic examination data . 9
4.4.6 Handling of units of measurement . 11
4.5 OEDD XML schema . 11
Annex A (informative) Ophthalmic examination data cases .12
Annex B (informative) Standard codes used for common data .13
Annex C (informative) Standard codes for ophthalmic examination data .14
Annex D (informative) Sample files .54
Bibliography . 153
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ISO/TS 22218-1:2023(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 215, Health informatics.
A list of all parts in the ISO 22218 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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ISO/TS 22218-1:2023(E)
Introduction
Opthalmic devices are used in hospitals and clinics to conduct examinations for patients. The primary
devices used in these opthalmic examinations provide measurement of refraction, corneal curvature,
intraocular pressure, lens power and visual acuity. Almost all patients who consult for a diagnosis in
ophthalmology undergo these examinations. Most ophthalmic hospitals and clinics use devices in these
examinations to provide the needed measurements. Since many different vendors supply the devices
to perform these measurements, the interoperability of examination results is important. In addition,
standard procedures for mutually communicating these measurements are required between the
ophthalmic examination devices and the Ophthalmic Information System (OIS).
These examinations are indispensable not only for ophthalmic medical care but also for prescriptions
for spectacles and contact lenses. Additionally, intraocular pressure measurement is important for
other ophthalmic procedures such as glaucoma assessment.
However, due to the differing data formats provided by these ophthalmic examination devices and
the lack of interoperability, integration of this information is difficult and potentially error prone.
Integration of each device’s information into an OIS or hospital information system (HIS) therefore
requires significant individual effort for each manufacturer’s device.
This document specifies the content and format for ophthalmic examination device measurements,
identifying that information that may be included in examination reports, as well as how it should be
formatted when communicated to an OIS, HIS or other similar system.
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TECHNICAL SPECIFICATION ISO/TS 22218-1:2023(E)
Health informatics — Ophthalmic examination device
data —
Part 1:
General examination devices
1 Scope
This document specifies the measurement data output formats for devices used in general ophthalmic
examiniations, including the following modalities:
— Refractometer (REF) Refraction
— Keratometer (KM) Corneal curvature
— Tonometer (TM) Intraocular pressure
— Lensmeter (LM) Spectacle lens power
— Phoroptor (PHOR) Visual acuity
This document only addresses text-based device reporting of ophthalmic examination device data
(OEDD). Images generated as needed during an ophthalmic examination are outside the scope of this
document.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
refractometer
device that measures the refractive state of the eye
Note 1 to entry: Measuring the refractive state of the eye is necessary to determine the refractive power of a
correction lens to restore normal vision.
Note 2 to entry: Measuring devices can provide both analog or digital readouts.
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ISO/TS 22218-1:2023(E)
3.2
intraocular pressure
IOP
measurement of the fluid pressure inside the eye
Note 1 to entry: This measurement is typically expressed in kPa; however, some devices also provide it in mmHg.
1 mmHg = 0,133 3 kPa
3.3
measured intraocular pressure
measured IOP
intraocular pressure that obtained without any compensation
Note 1 to entry: See corrected intraocular pressure (3.4).
3.4
corrected intraocular pressure
corrected IOP
intraocular pressure that results from compensation of the corneal thickness based on the measured
intraocular pressure
3.5
refractive power
ability of a lens or optical surface to change the curvature of incident wavefront or its direction by
refraction
3.6
interpupillary distance
PD
distance between the centres of the pupils when the eyes are fixating an object at an infinite distance in
the straight-ahead position
3.7
corneal curvature
radius of curvature of the anterior cornea
Note 1 to entry: It is expressed in mm.
3.8
visual acuity
number characterizing the ability of the visual system to recognize optotypes
[SOURCE: ISO 8596:2017, 3.3]
3.9
sphere
spherical power
sph
S
value of the back vertex power of a spherical-power lens or the vertex power in one of the two principal
meridians of an astigmatic-power lens, depending on the principal meridian chosen for reference
[SOURCE: ISO 13666:2019, 3.12.2]
3.10
cylindrical power
cylinder
cyl
plus or minus the astigmatic difference, depending on the principal meridian chosen for reference
Note 1 to entry: The commonly used symbol for cylindrical power is C.
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ISO/TS 22218-1:2023(E)
[SOURCE: ISO 13666:2019, 3.13.7, modified — Note 1 to entry modified.]
3.11
Maddox
type of ophthalmic examation that uses a Maddox rod
Note 1 to entry: A point source through a small Maddox rod (filter with thin cylindrical red glasses lined up) forms
a vertical red line when round glasses horizontally stand in a line, and forms a horizontal red line when round
glasses stand vertically in a line. For this property, a Maddox tangent scale (scale with a cruciform scale and a
point source at the center) is used to measure a heterophoria angle. By using a small Maddox rod horizontally
(vertically) and viewing a tangent scale, a vertical (horizontal) red line can be seen with each eye. By seeing a
point source at the center, a red line can be seen at the off-center position with the fellow eye. Measurement is
performed by reading the horizontal (vertical) scale of the position.
3.12
accommodation
type of repeated measurement that is performed using the time required for focusing on a visual target
Note 1 to entry: This measurement reveals the nature of accommodation disorder by classifying the appearance
of accommodation time into several types as contraction time, that is the time required for focusing on a near
visual target, or relaxation time for the time required for focusing on a far visual target.
3.13
AC/A ratio
ratio of the accommodative convergence amount for +1,0D and the accommodation stimulation
Note 1 to entry: This is determined using a fusion test.
3.14
vergence
simultaneous movement of both eyes in different directions
Note 1 to entry: This occurs when the line of sight is moved to objects at different distances (depths) from a viewer.
The movement of both eyes directed inward when one looks into the close distance is called “convergence”, and
the movement of both eyes directed outward when one looks into the far distance is called “divergence”.
Note 2 to entry: Vergence is one of disconjugate eye movement of right and left eyeballs in the opposite directions,
which is different from conjugate eye movement in which both eyes move in the same direction such as saccade
and pursuit eye movement. In addition, the word “vergence” is commonly used for eye movement in a horizontal
direction; however, besides this, vertical vergence and cyclovergence are included. The convergence divergence
movement changes this convergence angle. The simultaneous movement of both eyes in opposite directions
occurs when the line of sight is moved to objects at different depths; the convergence movement occurs when one
looks into the close distance from the far distance; and on the contrary, the divergence movement occurs when
one looks into the far distance from the close distance.
3.15
stereopsis
ability to use sensory information from both eyes to recognize three dimensional shaps sterioscopically
Note 1 to entry: This occurs when a planar image projected on the retina is subjected to integrative action in the
visual areas of the cerebral cortex, and is recognized as a three-dimensional shape in three dimensional space.
3.16
depth perception
ability to recognize the difference in distance to multiple targets
3.17
phoria
state where the ocular position during the binocular vision test is normal; however, ocular displacement,
infravergance or supravergence, appears as fusion disturbance
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ISO/TS 22218-1:2023(E)
3.18
aniseikonia
condition in which one eye perceives an image to be larger compared to the other eye and can occur in a
horizontal or vertical direction
3.19
ophthalmic information system
OIS
computer system that acquires, stores, retrieves and manages ophthalmic images and examination data
Note 1 to entry: The OIS gather and manage examination information from various ophthalmic devices and
submit persistent examination reports in CDA RMIM format to HIS.
3.20
deviceCDA
subset of the CDA RMIM dataset that only includes the information contained in a device
Note 1 to entry: Most ophthalmic examination devices do not support all the mandatory information required by
a complete CDA document, such as patient or operator identification. Additional information can be associated
after the report is sent to an OIS or HIS. For additional details, see Clause 4.
3.21
hospital information system
HIS
comprehensive, integrated information system designed to manage all the aspects of a hospital's
operation
Note 1 to entry: In many implementations, a HIS covers hospital's operation such as medical, administrative,
financial, and legal issues and the corresponding processing of services.
[11]
[SOURCE: IS4H-MM ]
3.22
optotype
variable-sized type used in testing visual acuity
4 Specifications
4.1 General
OEDD provides standards both for transferring clinical ophthalmic examination data from various
types of examination devices to an OIS, as well as submitting persistent reports based on those
examination data from an OIS to an HIS.
Exemplary use cases are detailed in Annex A
It is possible to handle multiple data types such as REF, kerato, IOP, and lens meter within one XML file.
It is acceptable to compile REF, kerato, IOP, and lens meter in one file or separate them into different
files. Within the file, is the top tag in accordance with the rules for CDA.
For details, refer to 4.3.
The standard codes used in this document are shown in Annex C, and sample XML files are shown in
Annex D.
4.2 deviceCDA and persistent examination reports
Most OEDD devices only output examination data and related information, and cannot provide
additional data items such as Patient, Operator, Custodian and Authentication.
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ISO/TS 22218-1:2023(E)
For such devices, OEDD introduces deviceCDA, a strict subset of CDA, that allows devices to transfer
examination data and related information as a deviceCDA dataset without the additional detailed
patient identification information that is required in complete CDA documents.
OIS plays the role of receiving examination data and related information as a deviceCDA dataset from
a device, and then submitting a persistent examination report to an HIS with additional information
required for the complete CDA dataset.
deviceCDA is not a complete CDA dataset but still conforms to the same syntax. OIS therefore prepares
a complete OEDD that includes the CDA RMIM dataset with information such as Patient, Operator,
Custodian and Authentication, and inserts the deviceCDA dataset received from the device into the
OEDD. See Figure 1.
Figure 1 — Concept of a deviceCDA
4.3 Data classification constitution in the file
Both a deviceCDA and a complete CDA file has and as the
top tag.
It is possible to collect information from all the OEDD classifications into one file, or they can be
separated into different deviceCDA/Complete CDA files. In the case of a single composite OEDD
deviceCDA/Complete CDA document, the data tags that are common across the devices shall be
specified once, and the OEDD data tags integrated separately. See Table 1.
When encountering a data classification not included in the OEDD specification (e.g., private extensions),
in which case, implementations shall ignore non-recognized data classifications and process the known
data classifications accordingly.
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ISO/TS 22218-1:2023(E)
Table 1 — Example deviceCDA file data block layouts
Common Data Common Data Common Data Common Data
REF Data REF Data TM Data LM Data
KR Data LM Data KR Data
TM Data PHOR Data
LM Data
File 1 File 2 File 3 File 4
4.4 OEDD structure
4.4.1 General
This document is compliant with CDA-R2. For this reason, the complete detailed file structure can be
1)
reviewed in HL7 CDA® Release 2.
In this document, only descriptions particular to ophthalmology are included.
1) HL7 CDA is the registered trademark of Health Level Seven International. This information is given for the
convenience of users of this document and does not constitute an endorsement by ISO of the product named.
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ISO/TS 22218-1:2023(E)
4.4.2 Data classifications
The data classifications of refractometer, keratometer, tonometer and such are maintained as attribute
value (type) of tags.
4.4.3 Attribute value and classification
Table 2 shows ophthalmic examination device data classification values.
Table 2 — OEDD Device Classification Values
Attribute value (code) Data classification
79898-3 Refractometer data
95298-6 Keratometer data
79896-7 Tonometer data
95318-2 Lensmeter data
79895-9 Auto Phoroptor data
Figure 2 shows the examples with refractometer (REF), keratometer (KM), tonometer (TM), lensmeter
2)
(LM) and phoropter (PHOR) data These examications are designated using LOINC® codes.
Figure 2 — OEDD section tags
4.4.4 Handling of common data
4.4.4.1 General
Common data, such as ophthalmic examination title, are described in the CDA Header part between the
tag and < structuredBody>. This common data will be present only once in a file.
4.4.4.2 Common data tags
The items to be described in the necessity column have the following meanings. See details in Table 3.
2) LOINC is the registered trademark of Regenstrief Institute. This information is given for the convenience of
users of this document and does not constitute an endorsement by ISO of the product named.
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ISO/TS 22218-1:2023(E)
Table 3 — Common data tags
a
Tag name Description Necessity
ClinicalDocument CDA-R2 D
Type ID. The compliant CDA R2 D
typeId
specifications are identified.
ID for unique identification D
id specified at hospitals, etc. or
groups
A code which represents the D
code
reporting category.
title Ex) Ophthalmic examinations D
Date & time of creation of the C
effectiveTime
file (yyyymmddhhmmss)
Confidentiality level code. D
The confidentiality value in
the HL7 vocabulary domain is
confidentialityCode
used.
Ex) code="N"
languageCode D
languageCode
Ex) code="jpn"
versionNumber Document version number D
recordTarget Patient D
patientRole Patient information D
Patient No. D
(number of the order of exam-
id b
ination)
Ex) extension="123456"
c
patient Patient name C
c
name Alphabetic expression C
c
family family name C
c
given Given name C
Regional ideographic or pho- O
name
c
netic name
c
family family name O
c
given Given name O
Patient's sex C
administrativeGenderCode
d
EX) F/M/UN
Patient’s date of birth (yyyym- C
birthTime
mdd)
author Author D
a
The items in the Necessity column have the following meanings:
D - Tags and values are necessary for both Complete CDA and deviceCDA
C - Tags and values are necessary for Complete CDA
O - No tags or values are necessary
b
Multiple settings are allowed for Patient No. Also, nullFlavor="NI" is allowed.
c
Multiple settings are allowed for Patient name. If First name and Last name cannot be separated, the Last name should
be entered in the First name section. Also, nullFlavor="NI" is allowed.
d
Refer to Annex B.
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ISO/TS 22218-1:2023(E)
TTabablele 3 3 ((ccoonnttiinnueuedd))
a
Tag name Description Necessity
Date & time of creation D
time
(yyyymmddhhmmss)
Information of the organiza- D
assignedAuthor tion that prepares the docu-
ment.
Assigned Author ID D
id
"NI" : If id is none
assignedAuthoringDevice Assigned Authoring Device D
Model name and No. for dis- D
manufacturerModelName tinction among the devices of
the same model
softwareName Software and ROM version D
representedOrganization Represented Organization C
Represented Organization ID C
id
"NI": If id is none
name Company name C
custodian custodian C
assignedCustodian Assigned Custodian C
Represented Custodian Organ- C
representedCustodianOrganization
ization
Represented Custodian Organ- C
ization ID
id
"NI": If id is none
documentationOf Operator C
serviceEvent code C
serviceEvent
EX) classCode="ACSN"
code serviceEvent code C
performer type code C
performer
EX) typeCode="PRF"
Function Code C
functionCode
d
EX) code="SNRS"
assignedEntity assignedEntity C
id Operator ID C
a
The items in the Necessity column have the following meanings:
D - Tags and values are necessary for both Complete CDA and deviceCDA
C - Tags and values are necessary for Complete CDA
O - No tags or values are necessary
b
Multiple settings are allowed for Patient No. Also, nullFlavor="NI" is allowed.
c
Multiple settings are allowed for Patient name. If First name and Last name cannot be separated, the Last name should
be entered in the First name section. Also, nullFlavor="NI" is allowed.
d
Refer to Annex B.
4.4.5 Handling of ophthalmic examination data
4.4.5.1 General
Examination data are described in the section of the deviceCDA as follows:
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ISO/TS 22218-1:2023(E)
---(Refer to 4.4.5.2 for detailed content)
4.4.5.2 Ophthalmic examination data tags
Table 4 shows basic composition of tags used for ophthalmic examination data:
Table 4 — Ophthalmic examination data tags
a
Tag name Description Necessity
component CDA-R2 component D
structuredBody D
Medication information tag can be optionally defined here -
component CDA-R2 component O
Section O
section
Ex) classCode="DOCSECT" mood-
Code="EVN"
Title of drug to be administrated O
title
(mydriatic agent)
Drug name O
text
EX) Mydrin-P
entry O
Ex) classCode="OBS" mood- O
Code="EVN"
observation
(OBS=observation, EVN=exami-
nation results)
drug code O
code
b
EX) 1319810Q1053
Examination tag defined here -
component CDA-R2 component D
section Section D
LOINC®'s Exam Details Code D
code
EX) Set code of LOINC® for REF:
"79898-3"
a
The items in the Necessity column have the following meanings:
D - Tags and values are necessary for both Complete CDA and deviceCDA
O - No tags or values are necessary
b d
This drug code is for the mydriatic solution (Mydrin® -P) listed in the National Health Insurance Drug Price List
commonly used in Japan.
c
Refer to Annex C for detail of examination data measured by each ophthalmic examination device.
d
Mydrin is the registered trademark of Santen Pharmaceutical Co., Ltd. This information is given for the convenience of
users of this document and does not constitute an endorsement by ISO of the product named.
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ISO/TS 22218-1:2023(E)
TTabablele 4 4 ((ccoonnttiinnueuedd))
a
Tag name Description Necessity
examination title D
title
(HTML format)
text detail of examination D
entry D
Ex) classCode="OBS" mood- D
Code="EVN"
observation
(OBS=observation, EVN=exami-
nation results)
Examination code D
code
Ex) Refraction Sphere Right=
"28687-2"
Date & time of creation of the file D
effectiveTime
(yyyymmddhhmmss)
c
Value examination data & unit D
entryRelationship Detailed examination data D
sequenceNumber Measurement number D
Ex) classCode="OBS" mood- D
Code="EVN"
observation
(OBS=observation, EVN=exami-
nation results)
Examination code D
code
Ex) Refraction Sphere Right=
"28687-2"
c
value examination data & unit D
a
The items in the Necessity column have the following meanings:
D - Tags and values are necessary for both Complete CDA and deviceCDA
O - No tags or values are necessary
b d
This drug code is for the mydriatic solution (Mydrin® -P) listed in the National Health Insurance Drug Price List
c
...
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