ISO/TS 22218-2:2023

TECHNICAL ISO/TS
SPECIFICATION 22218-2
First edition
2023-01
Health informatics — Ophthalmic
examination device data —
Part 2:
Specular microscope
Informatique de santé — Données relatives aux dispositifs d'examen
ophtalmique —
Partie 2: Microscope spéculaire
Reference number
© ISO 2023
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Specifications . 3
4.1 General . 3
4.2 deviceCDA and persistent examination reports . 3
4.3 Data classification constitution in the file . 4
4.4 OEDD structure . 5
4.4.1 General . 5
4.4.2 Data classifications . 5
4.4.3 Attribute value and classification . 5
4.4.4 Handling of common data . 6
4.4.5 Handling of ophthalmic examination data . 8
4.4.6 Handling of units of measurement . 9
4.5 OEDD XML schema . 9
Annex A (informative) Use cases of specular microscope .11
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 .19
Bibliography .35
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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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.
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iv
Introduction
Ophthalmic devices are used in hospitals and clinics to examine patients. The primary devices used in
these ophthalmic examinations provide the 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.
Besides such general ophthalmic devices, specular microscopes are often used to capture and analyze
an image of the corneal endothelium, which dehydrates the corneal stroma and maintains the cornea’s
clarity. Thus, measuring the cell density of the corneal endothelium is one of the most crucial and reliable
methods to determine its condition. The analysis results of the specular microscope are indispensable
for not only patients experiencing trouble in the cornea but also safe prescriptions for contact lenses.
Like other ophthalmic devices, various manufacturers supply specular microscopes. Thus, standardized
procedures for mutually communicating analysis results are crucial between the specular microscope
and ophthalmic information system (OIS).
However, the integration of this information is complex and potentially error-prone owing to variable
data formats provided by specular microscopes from different manufacturers and the lack of
interoperability. Thus, the integration of analysis results from various specular microscopes into an
OIS or hospital information system (HIS) warrants significant individual effort for each manufacturer’s
specular microscope.
This document specifies the content and format for the analysis results of specular microscopes,
identifying the information that could be included in the analysis results, as well as how it should be
formatted when communicated to an OIS, HIS, or other similar systems.
v
TECHNICAL SPECIFICATION ISO/TS 22218-2:2023(E)
Health informatics — Ophthalmic examination device
data —
Part 2:
Specular microscope
1 Scope
This document specifies the data output formats for the specular microscope. The data are usually
sent from the specular microscope to either an ophthalmic information system (OIS) or a hospital
information system (HIS).
This document addresses text-based analysis reporting of the specular microscope measured and
analysed data such as the central corneal thickness, the density of endothelial cells per 1 mm , the
coefficient variant, and the ratio of endothelial cells with a hexagonal shape.
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
corneal endothelium
monolayer of endothelial cells that constitutes the posterior corneal surface
Note 1 to entry: The corneal endothelium dehydrates the corneal stroma and maintains the cornea’s clarity.
Note 2 to entry: Measuring the endothelial cell density provides valuable information about the cornea’s
condition.
3.2
endothelial cell density
CD
number indicating how many endothelial cells are present in one square millimeter (mm )
Note 1 to entry: This value is often referenced to determine the condition of the corneal endothelium. If the
corneal endothelium is young and healthy, the value is high, and if the corneal endothelium is old and damaged,
the value is low.
3.3
coefficient of variation
CV
ratio of the standard deviation to the mean in cell size, which is standardized measure of the dispersion
of the size of each endothelial cell
Note 1 to entry: This value is often referenced to determine the condition of the corneal endothelium, owing to
uniform cell size, healthy corneal endothelium has a small CV value.
3.4
hexagonality
HEX
morphology of endothelial cells, usually the percentage of hexagonal cells
Note 1 to entry: This value is often referenced to determine the condition of the corneal endothelium. Cells of
healthy corneal endothelium have uniform size and are primarily hexagonal.
3.5
dry eye
disease in which the stability of the tear film is reduced
3.6
Fuchs’ dystrophy
slowly progressing corneal dystrophy in which fluid builds up and the cornea gets swollen and puffy
3.7
bullous keratopathy
eye disorder due to oedema that involves a swelling of the cornea
3.8
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.
[SOURCE: ISO/TS 22218-1:2022, 3.19]
3.9
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, and additional information can be accessed
after the report is sent to an OIS or HIS.
[SOURCE: ISO/TS 22218-1:2022, 3.20]
3.10
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.
[6]
[SOURCE: IS4H-MM ]
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 a HIS. The specular microscope is one such examination device.
Exemplary use cases are detailed in Annex A.
It is possible to handle multiple data types such as SPECULAR (Specular microscope), REF
(Refractometer), KM (Keratometer), TM (Tonometer), LM (Lensmeter), and PHOR (Phoroptor) within
one XML file. It is acceptable to compile SPECULAR, REF, KM, TM, LM, and PHOR in one file or separate
them into different files. Within the file, is the top tag in accordance with the rules
for CDA.
REF (Refractometer), KM (Keratometer), TM (Tonometer), LM (Lensmeter), and PHOR (Phoroptor) are
also ophthalmic examination devices described in this document.
For details, see 4.3.
The standard codes used in this document are shown in Annex C, and a sample XML file is 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, Oper
...