SIST EN ISO 11979-3:2013

Ophthalmic implants - Intraocular lenses - Part 3: Mechanical properties and test methods (ISO 11979-3:2012)

This part of ISO 11979 specifies requirements and test methods for certain mechanical properties of intraocular lenses (IOLs). It is applicable to all types of IOLs intended for implantation in the anterior segment of the human eye, excluding corneal implants, provided that the test method is appropriate to the particular IOL design.

Ophthalmische Implantate - Intraokularlinsen - Teil 3: Mechanische Eigenschaften und Prüfverfahren (ISO 11979-3:2012)

Dieser Teil von ISO 11979 legt Anforderungen und Prüfverfahren für bestimmte mechanische Eigenschaften von Intraokularlinsen (IOLs) fest. Er gilt mit der Ausnahme von Hornhautimplantaten für alle Typen von Intraokularlinsen, die für die Implantation in das vordere Segment des menschlichen Auges vorgesehen sind, sofern das angegebene
Verfahren für das fragliche Design geeignet ist.

Implants ophtalmiques - Lentilles intraoculaires - Partie 3: Propriétés mécaniques et méthodes d'essai (ISO 11979-3:2012)

L'ISO 11979-3:2012 spécifie les exigences et les méthodes d'essai élaborées pour certaines propriétés mécaniques des lentilles intraoculaires (LIO).
L'ISO 11979-3:2012 s'applique à tous les types de LIO destinées à une implantation dans le segment antérieur de l'oeil humain, à l'exclusion des implants de la cornée, sous réserve que la méthode d'essai soit appropriée pour un modèle de LIO en particulier.

Očesni vsadki (implantati) - Intraokularne leče - 3. del: Mehanske lastnosti in preskusne metode (ISO 11979-3:2012)

Ta del standarda ISO 11979 določa zahteve in preskusne metode za nekatere mehanske lastnosti intraokularnih leč (IOL). Uporablja se za vse vrste intraokularnih leč za implantacijo v anteriorni segment človeškega očesa, razen za roženične vsadke, če je preskusna metoda ustrezna za posebno zasnovo intraokularne leče.

General Information

• Status: Published
• Public Enquiry End Date: 14-Nov-2011
• Publication Date: 14-Feb-2013
• ICS: 11.040.70 - Ophthalmic equipment
• Technical Committee: VAZ - Healthcare
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Feb-2013
• Due Date: 08-Apr-2013
• Completion Date: 15-Feb-2013
• Ref Project: EN ISO 11979-3:2012 - Ophthalmic implants - Intraocular lenses - Part 3: Mechanical properties and test methods (ISO 11979-3:2012)

Relations

• Replaces: SIST EN ISO 11979-3:2006 - Ophthalmic implants - Intraocular lenses - Part 3: Mechanical properties and test methods (ISO 11979-3:2006)
• Effective Date: 01-Mar-2013
• Replaces: SIST EN ISO 11979-3:2006 - Ophthalmic implants - Intraocular lenses - Part 3: Mechanical properties and test methods (ISO 11979-3:2006)
• Effective Date: 08-Jun-2022

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 11979-3:2013
01-marec-2013
1DGRPHãþD
SIST EN ISO 11979-3:2006
2þHVQLYVDGNLLPSODQWDWL,QWUDRNXODUQHOHþHGHO0HKDQVNHODVWQRVWLLQ
SUHVNXVQHPHWRGH,62
Ophthalmic implants - Intraocular lenses - Part 3: Mechanical properties and test
methods (ISO 11979-3:2012)
Ophthalmische Implantate - Intraokularlinsen - Teil 3: Mechanische Eigenschaften und
Prüfverfahren (ISO 11979-3:2012)
Implants ophtalmiques - Lentilles intraoculaires - Partie 3: Propriétés mécaniques et
méthodes d'essai (ISO 11979-3:2012)
Ta slovenski standard je istoveten z: EN ISO 11979-3:2012
ICS:
11.040.70 Oftalmološka oprema Ophthalmic equipment
SIST EN ISO 11979-3:2013 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 11979-3:2013

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SIST EN ISO 11979-3:2013


EUROPEAN STANDARD
EN ISO 11979-3

NORME EUROPÉENNE

EUROPÄISCHE NORM
December 2012
ICS 11.040.70 Supersedes EN ISO 11979-3:2006
English Version
Ophthalmic implants - Intraocular lenses - Part 3: Mechanical
properties and test methods (ISO 11979-3:2012)
Implants ophtalmiques - Lentilles intraoculaires - Partie 3: Ophthalmische Implantate - Intraokularlinsen - Teil 3:
Propriétés mécaniques et méthodes d'essai (ISO 11979- Mechanische Eigenschaften und Prüfverfahren (ISO
3:2012) 11979-3:2012)
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 11979-3:2012: E
worldwide for CEN national Members.

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SIST EN ISO 11979-3:2013
EN ISO 11979-3:2012 (E)
Contents Page
Foreword . 3

2

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SIST EN ISO 11979-3:2013
EN ISO 11979-3:2012 (E)
Foreword
This document (EN ISO 11979-3:2012) 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.
This document supersedes EN ISO 11979-3:2006.
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 11979-3:2012 has been approved by CEN as a EN ISO 11979-3:2012 without any
modification.

3

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SIST EN ISO 11979-3:2013

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SIST EN ISO 11979-3:2013
INTERNATIONAL ISO
STANDARD 11979-3
Third edition
2012-12-01
Ophthalmic implants — Intraocular
lenses —
Part 3:
Mechanical properties and test methods
Implants ophtalmiques — Lentilles intraoculaires —
Partie 3: Propriétés mécaniques et méthodes d’essai
Reference number
ISO 11979-3:2012(E)
©
ISO 2012

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SIST EN ISO 11979-3:2013
ISO 11979-3:2012(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2012
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
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved

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SIST EN ISO 11979-3:2013
ISO 11979-3:2012(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 1
4.1 General . 1
4.2 Tolerances and dimensions . 2
4.3 Clearance analysis (anterior chamber lenses only) . 2
4.4 Compression force . 2
4.5 Axial displacement in compression . 2
4.6 Optic decentration . 3
4.7 Optic tilt . 3
4.8 Angle of contact . 3
4.9 Compression force decay . 3
4.10 Dynamic fatigue durability . 3
4.11 Surgical manipulation . 4
4.12 Surface and bulk homogeneity . 4
5 Recovery of properties following simulated surgical manipulation .4
6 Additions for accommodating IOLs (AIOLs) . 4
Annex A (normative) Measurement of compression force . 6
Annex B (normative) Measurement of axial displacement in compression .9
Annex C (normative) Measurement of optic decentration .12
Annex D (normative) Measurement of optic tilt.15
Annex E (normative) Measurement of angle of contact .19
Annex F (normative) Testing of compression force decay .22
Annex G (normative) Testing of dynamic fatigue durability.23
Annex H (informative) Measurement of loop pull strength .25
Annex I (informative) Clearance analysis .27
Annex J (informative) Precision .30
Bibliography .31
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SIST EN ISO 11979-3:2013
ISO 11979-3:2012(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 11979-3 was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee
SC 7, Ophthalmic optics and instruments.
This third edition cancels and replaces the second edition (ISO 11979-3:2006), which has been technically
revised in order to include relevant requirements and test methods for toric intraocular lenses and
accommodating intraocular lenses.
ISO 11979 consists of the following parts, under the general title Ophthalmic implants — Intraocular lenses:
— Part 1: Vocabulary
— Part 2: Optical properties and test methods
— Part 3: Mechanical properties and test methods
— Part 4: Labelling and information
— Part 5: Biocompatibility
— Part 6: Shelf-life and transport stability
— Part 7: Clinical investigations
— Part 8: Fundamental requirements
— Part 9: Multifocal intraocular lenses
— Part 10: Phakic intraocular lenses
iv © ISO 2012 – All rights reserved

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SIST EN ISO 11979-3:2013
ISO 11979-3:2012(E)

Introduction
This part of ISO 11979 contains methods for which requirements are given and methods for which no
requirements are formulated. The former are considered essential for the safety or performance of the
intraocular lens, while the latter provide essential information to the ophthalmic surgeon or are used
for other purposes.
A special purpose is the use of mechanical data to assess the need for clinical investigation of
[7]
modifications of existing models as described in ISO 11979-7 . Because of the complexity of this
[8]
analysis, detailed descriptions and examples have been given in ISO/TR 22979 . Due to the wide
variety of intraocular lens designs already on the market, it has not been possible to devise test methods
that are applicable to every design under all circumstances. It can be anticipated that new materials
currently under development will result in drastically new designs that will require modified or other
test methods. As with all standards, it is then up to the parties using the standard to modify or develop
corresponding methods and give rationale and validation for them in a spirit that is consistent with this
part of ISO 11979.
In cases where different tolerances have been given depending on material or design, they reflect an
existing situation with well-established products.
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SIST EN ISO 11979-3:2013

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SIST EN ISO 11979-3:2013
INTERNATIONAL STANDARD ISO 11979-3:2012(E)
Ophthalmic implants — Intraocular lenses —
Part 3:
Mechanical properties and test methods
1 Scope
This part of ISO 11979 specifies requirements and test methods for certain mechanical properties of
intraocular lenses (IOLs).
It is applicable to all types of IOLs intended for implantation in the anterior segment of the human eye,
excluding corneal implants, provided that the test method is appropriate to the particular IOL design.
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.
ISO 11979-1, Ophthalmic implants — Intraocular lenses — Part 1: Vocabulary
ISO 11979-2, Ophthalmic implants — Intraocular lenses — Part 2: Optical properties and test methods
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11979-1 apply.
4 Requirements
4.1 General
For all IOLs, the mechanical properties shall be determined at in situ conditions. The precise composition
of the solution used shall be reported in all cases. Alternative test conditions, e.g. room temperature
conditions, may be used if a justification to deviate from in situ is given. The alternative test conditions
shall be specified in the test reports.
For each of the methods described below, tests shall be performed on a minimum of three IOL lots of
medium dioptric power. If dioptric power affects the property tested, the lots shall comprise one each of
low, medium and high dioptric powers. For toric intraocular lenses, half of each of these three lots shall
contain intraocular lenses with the highest cylindrical power, and the other half shall contain intraocular
lenses with the lowest cylindrical power. The minimum sample size for each test shall be 10 IOLs per lot.
The lots shall be representative of IOLs being marketed. In all cases, the sampling criteria applied shall
be reported. Means and standard deviations shall be reported for the pooled samples.
If, for certain designs and certain applications, a specific test method described in this part of ISO 11979
is not applicable, the IOL manufacturer can devise a corresponding test method and provide a validation
and rationale for it.
For accommodating IOLs (AIOLs) the theoretical mechanism of action to change the power of the eye
shall be described e.g. the change of curvature or the movement of lens elements under compression.
The general factors determining this action shall be characterized and specified. Further mechanical
testing over a range that includes the maximum and minimum limits of the theoretical mechanism of
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SIST EN ISO 11979-3:2013
ISO 11979-3:2012(E)

action shall be performed. If the dynamic response to the mechanism of action is time dependent, this
time dependency shall be characterized.
4.2 Tolerances and dimensions
The tolerances for overall diameter, vault height and sagitta are given in Table 1.
Table 1 — Tolerances of overall diameter, vault height and sagitta
Test method Overall diameter Vault height Sagitta
Anterior chamber IOLs ±0,20 mm ±0,15 mm ±0,25 mm
Multi piece posterior chamber IOLs ±0,30 mm ±0,35 mm ±0,45 mm
Other IOLs ±0,20 mm ±0,25 mm ±0,35 mm
The tolerance on the clear optic shall be ± 0,15 mm. The diameter of the clear optic shall be greater than
4,25 mm in any meridian. The tolerance on the dimensions of the body shall be ± 0,10 mm. For ellipsoid
IOLs, the dimensions of the body shall be reported as (short axis) × (long axis).
+00, 5
The tolerance on the diameter of the positioning hole shall be nominal mm.
( )
0
Dimensions for which tolerances are given above shall be specified in the manufacturer’s design
documentation. Some dimensions may vary with dioptric power, hence different specifications may
apply to individual powers of an intraocular lens design.
4.3 Clearance analysis (anterior chamber lenses only)
An empirical analysis of anatomic placement shall be performed for anterior chamber lenses to evaluate
the most proximate points with relation to the anatomical structures of the eye. The clearance of the
anterior surface of the IOL optic in relation to the endothelial layer of the cornea shall be determined
for the lens at its minimum recommended diameter in its compressed state. In addition the separation
between the posterior surface of the IOL optic and the iris shall be determined. For phakic IOLs,
the separation between the posterior surface of the IOL optic and the crystalline lens shall also be
determined. These results shall be considered in the risk analysis. The theoretical eye model in Annex I
can be used in the evaluation.
The manufacturer shall strive for a clearance of at least 1 mm under worst-case conditions, i.e. conditions
which would result in the minimum amount of clearance.
4.4 Compression force
Using the method described in Annex A, the compression force shall be measured and reported as follows:
a) for IOLs intended for capsular bag placement, with the haptics compressed to a diameter of 10 mm;
b) for IOLs intended for sulcus placement, with the haptics compressed to a diameter of 11 mm;
c) for IOLs intended for both capsular bag and sulcus placement, with the haptics compressed to both
a diameter of 10 mm and a diameter of 11 mm;
d) for anterior chamber IOLs, with the haptics compressed to the minimum and maximum intended
compressed diameters recommended by the manufacturer in the product literature.
4.5 Axial displacement in compression
Using the method described in Annex B, the axial displacement in compression shall be measured and
reported at the same diameters that were used for the measurement of compression force (see 4.4).
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SIST EN ISO 11979-3:2013
ISO 11979-3:2012(E)

In addition, for anterior chamber IOLs, the vault height and the sagitta in the compressed state shall be
given in the product literature as a function of dioptric power at the minimum and maximum intended
compressed diameters, as specified in 4.4.
4.6 Optic decentration
Using the method described in Annex C, the optic decentration shall be measured and reported at the
same diameters that were used for the measurement of compression force (see 4.4).
The sum of the arithmetic mean and two standard deviations of the optic decentration shall not exceed
10 % of the clear optic.
4.7 Optic tilt
Using the method described in Annex D, the optic tilt shall be measured and reported at the same
diameters that were used for the measurement of compression force (see 4.4).
The sum of the arithmetic mean and two standard deviations of the optic tilt shall not exceed 5°.
4.8 Angle of contact
Using the method described in Annex E, the angle of contact shall be measured and reported at the same
diameters that were used for the measurement of compression force (see 4.4).
NOTE The angle of contact is a measured approximation of the total haptic contact with the supporting
ocular tissue.
4.9 Compression force decay
Using the method described in Annex F, the compression force decay shall be tested and reported at the
same diameters that were used for the measurement of compression force (see 4.4).
The loops of IOLs are designed to exert some pressure on eye structures as a means of keeping the IOL
in position and shall continue to do so for some time after implantation.
Results shall be reported as residual compression force after 24 h ± 2 h in compression at each required
compressed diameter.
4.10 Dynamic fatigue durability
All loops shall be capable of withstanding, without breaking, 250 000 cycles of near-sinusoidal
deformation of ± 0,25 mm around the compressed distance.
Using the method described in Annex G, fatigue testing shall be performed as follows:
a) for IOLs intended for capsular bag placement, at a compressed distance of 5,0 mm between the
testing plate and the centre of the optic;
b) for IOLs intended for sulcus placement, at a compressed distance of 5,5 mm between the testing
plate and the centre of the optic;
c) for IOLs intended for both capsular bag and sulcus placement, at a compressed distance of 5,0 mm
between the testing plate and the centre of the optic;
d) for anterior chamber IOLs, at a distance between the testing plate and the centre of the optic,
corresponding to half the maximum intended compressed diameter as recommended by the
manufacturer in the product literature.
This test shall be carried out only for IOL designs in which the loop will be in a compressed state when
implanted. The frequency shall be between 1 Hz and 10 Hz.
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SIST EN ISO 11979-3:2013
ISO 11979-3:2012(E)

Higher frequencies can be used if it is verified that the loop follows the testing plate without lag at all times.
No loop tested shall break.
For IOLs designed to move axially under compression, additional testing shall be considered.
4.11 Surgical manipulation
The IOL manufacturer shall provide evidence that the loops of an IOL design are capable of withstanding
surgical manipulations without failure. An appropriate test method and specification shall be established
by the manufacturer to ensure that the device does not fail at typical deformations. A test method,
useful for some designs with loops, is given in Annex H.
4.12 Surface and bulk homogeneity
The IOL shall be essentially free from defects, i.e. deviations from surface and bulk homogeneity
that are not intended features of the design, including all kinds of surface defects such as scratches,
digs, protrusions, cracks, roughness, etc., as well as bulk defects such as inclusions, bubbles, striae,
discoloration, etc. The lens shall be inspected at 10 × magnification under optimal lighting conditions;
any questionable or critical areas shall be viewed at higher magnification.
5 Recovery of properties following simulated surgical manipulation
The testing in this clause applies only to IOLs of which the optic is intended to be folded or compressed
during implantation. Perform testing on 10 lenses of each of the dioptric powers with the smallest
and largest cross-sectional dimensions. In practice this will typically be 10 lenses with the lowest
and 10 lenses with the highest dioptric power. For toric intraocular lenses, half of each of these lens
groups shall contain intraocular lenses with the highest cylindrical power, and the other half shall
contain intraocular lenses with the lowest cylindrical power. Follow the instructions supplied by the
manufacturer, using recommended lubricants and instrumentation. To determine the acceptable time
during which the lens is allowed to be kept deformed prior to implantation, maintain the deformed state
for a period of time. This time shall not be shorter than 3 min. Times in excess of 20 min need not be
investigated. The time used shall be reported.
After release from the deformed state, allow the lens to relax at in situ conditions up to 24 h ± 2 h. The
time used shall be reported. Subsequently:
a) measure dioptric power and image quality in accordance with ISO 11979-2;
b) measure overall diameter and sagitta in accordance with 4.2;
c) inspect for surface and bulk homogeneity in accordance with 4.12.
The results shall be reported and are acceptable if they remain within manufacturing specifications
of the product.
6 Additions for accommodating IOLs (AIOLs)
6.1 Designs comprising multiple optical elements shall be evaluated on the alignment of the optics
relative to each other in terms of centration. The effects of decentration on the optical performance of the
AIOL shall be used to determine appropriate tolerances.
6.2 Designs comprising multiple optical elements shall be evaluated on the alignment of the optics
relative to each other in terms of tilt. The effects of optic tilt on the optical performance of the AIOL shall
be used to determine appropriate tolerances.
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SIST EN ISO 11979-3:2013
ISO 11979-3:2012(E)

6.3 Using the principle described in 4.10, the theoretical motion of the AIOL in the eye shall be replicated
for at least 1 million cycles. In addition to evaluating any damage of the AIOL after this treatment, the
mechanical characteristics that determine the performance of the AIOL shall be assessed and shall not be
found altered to an extent that can be clinically significant. Any other dynamic properties influencing the
performance of the AIOL shall be evaluated. If the theoretical action does not include a radial compression
of the haptic of 0,5 mm (±0,25 mm), the test in 4.10 shall be additionally performed.
6.4 If indicated by risk analysis and assessment, additional testing can be required to demonstrate
the effect of aging on the continued functionality of the device. If the lens is meant to move or change
shape, testing must elucidate the effect of ageing on movement or shape change (or other changes, such
as refractive index).
6.5 Mechanical characteristics that affect the ability of an AIOL to function shall be demonstrated not
to change to an extent that can be clinically significant following simulated surgical manipulation for
implantation.
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SIST EN ISO 11979-3:2013
ISO 11979-3:2012(E)

Annex A
(normative)

Measurement of compression force
A.1 Principle
The force exerted by the loops is measured when the IOL is confined to a prescribed diameter with the
movement of the body being unrestricted.
A.2 Apparatus
A diagram of the apparatus is shown in Figures A.1 and A.2 and comprises the following.
A.2.1 Two anvils, with
...