SIST EN ISO 22665:2013

SLOVENSKI STANDARD
01-marec-2013
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Ophthalmic optics and instruments - Instruments to measure axial distances in the eye
(ISO 22665:2012)
Augenoptik und ophthalmische Instrumente - Instrumente zur Messung der Achslänge
des Auges (ISO 22665:2012)
Optique et instruments ophtalmiques - Appareil pour la mesure de la longueur axiale de
l'oeil (ISO 22665:2012)
Ta slovenski standard je istoveten z: EN ISO 22665:2012
ICS:
11.040.70 Oftalmološka oprema Ophthalmic equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 22665
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2012
ICS 11.040.70
English Version
Ophthalmic optics and instruments - Instruments to measure
axial distances in the eye (ISO 22665:2012)
Optique et instruments ophtalmiques - Appareil pour le Augenoptik und ophthalmische Instrumente - Instrumente
mesurage de la longueur axiale de l'oeil (ISO 22665:2012) zur Messung der Achslänge des Auges (ISO 22665:2012)
This European Standard was approved by CEN on 30 November 2012.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 22665:2012: E
worldwide for CEN national Members.

Contents Page
Foreword . 3

Foreword
This document (EN ISO 22665:2012) has been prepared by Technical Committee ISO/TC 172 "Optics and
photonics" in collaboration with Technical Committee CEN/TC 170 “Ophthalmic optics” the secretariat of which
is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by June 2013, and conflicting national standards shall be withdrawn at
the latest by June 2013.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 22665:2012 has been approved by CEN as a EN ISO 22665:2012 without any modification.

INTERNATIONAL ISO
STANDARD 22665
First edition
2012-12-01
Ophthalmic optics and instruments —
Instruments to measure axial distances in
the eye
Optique et instruments ophtalmiques — Appareil pour le mesurage de
la longueur axiale de l’oeil
Reference number
ISO 22665:2012(E)
©
ISO 2012
ISO 22665:2012(E)
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
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Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
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Published in Switzerland
ii © ISO 2012 – All rights reserved

ISO 22665:2012(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 through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 22665 was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 7,
Ophthalmic optics and instruments.
ISO 22665:2012(E)
Introduction
The measurement of the axial length of the human eye is one of the pre-requisites for the calculation of the
necessary power of an artificial lens that is to be implanted in the eye during cataract and/or refractive surgery.
Since the 1950s ultrasound biometry instruments have been used for ocular distance measurements.
Depending on how the sound waves are coupled into the eye, two different measurement methods are applied
in ultrasound biometry: immersion and contact techniques. In recent years, optical biometry instruments based
on partial coherence interferometry have established themselves as an alternative to echometry.
Neither instrument is calibrated against a common standard. As a result, there are systematic differences between
measurements taken with different biometers. The resulting errors can affect surgical outcomes for patients.
iv © ISO 2012 – All rights reserved

INTERNATIONAL STANDARD ISO 22665:2012(E)
Ophthalmic optics and instruments — Instruments to measure
axial distances in the eye
1 Scope
This International Standard is applicable to instruments and methods used for measuring the axial length of
the human eye.
It defines minimum requirements for such instruments and systems and defines test methods and procedures
to verify that a system or instrument qualifies as an axial length measuring device in accordance with this
International Standard.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
IEC 60601-1, Medical electrical equipment ― Part 1: General requirements for basic safety and essential performance
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
axial length
distance along the axis of a human eye between the anterior corneal surface to either the inner limiting
membrane (ILM) of the retina or the retinal pigment epithelium (RPE) of the retina
NOTE The separation between the ILM (anterior retina) and RPE (posterior retina) is approximately 100 µm at the
centre of the fovea and 300 µm immediately outside the fovea. Different methods exist to assess axial length, e.g. peak
and rising edge detection of fundus echoes in ultrasound instruments (using ILM) or determination of the optical path
length to the RPE in optical biometry.
3.2
aphakic mode
measurement mode and/or instrument setting for an axial length measuring device which is to be used for the
measurement of an aphakic eye (eye without lens)
3.3
contact ultrasound
contact mode
coupling technique in echo biometry by which the measuring transducer probe is in direct contact with the cornea
3.4
echo biometry
method to determine the axial length of a human eye by measuring the time of flight of an ultrasound pulse
between two echo-generating structures in the eye
3.5
group refractive index
ratio c /c between the speed of light in vacuum (c ) and the group velocity of light propagation (c ) through a
0 g 0 g
medium or a biological tissue
ISO 22665:2012(E)
3.6
immersion ultrasound
immersion mode
coupling technique in echo biometry by which the measuring transducer probe is separated from the cornea
by a water or liquid standoff
3.7
optical biometry
optical method to measure the axial length of a human eye
3.8
phakic mode
measurement mode and/or instrument setting for an axial length measuring device which is to be used for the
measurement of a phakic eye (eye with a crystalline lens)
3.9
acoustical impedance
Z
material property defined as the product of the velocity of sound in that material with its density:
Z =×υρ
where
υ is the velocity of sound in the material;
ρ is the density of the material.
4 Requirements
The axial length measuring device shall conform to the requirements given below. Conformity shall be verified
as described in Clause 5.
The radial and axial dimensions of three test bodies conforming to the requirements of Annex A shall be
determined using the instrument under test and shall be compared t
...