SIST EN ISO 11979-9:2006
(Main)Ophthalmic implants - Intraocular lenses - Part 9: Multifocal intraocular lenses (ISO 11979-9:2006)
Ophthalmic implants - Intraocular lenses - Part 9: Multifocal intraocular lenses (ISO 11979-9:2006)
This standard applies to any intraocular lens meant to provide two or more powers whose primary indications are the correction of aphakia and the improvement of near and/or intermediate uncorrected visual acuity.
Ophthalmische Implantate - Intraokularlinsen - Teil 9: Multifokale Intraokularlinsen (ISO 11979-9:2006)
Dieser Teil von ISO 11979 gilt für alle Intraokularlinsen, deren Optik zwei oder mehr rotationssymmetrische Brechkraftwerte hat und deren primäre Aufgabe in der Korrektur von Aphakie mit dem zusätzlichen Nutzen eines Sehbereichs von mehr als einer Entfernung (z. B. fern und nah) besteht.
ANMERKUNG Die in diesem Teil von ISO 11979 verwendete Bezeichnung Nahsehen umfasst einen Sehbereich in der jeweils angegebenen Entfernung, also z. B. nahe und/oder mittlere Entfernungen.
Implants ophtalmiques - Lentilles intraoculaires - Partie 9: Lentilles intraoculaires multifocales (ISO 11979-9:2006)
L'ISO 11979-9:2006 s'applique à toute lentille intraoculaire caractérisée par des propriétés optiques qui lui permettent de fournir au moins deux puissances présentant une symétrie de révolution et dont l'indication principale est la correction de l'aphakie tout en présentant l'avantage d'une vision utile à plusieurs distances (par exemple de près et de loin).
Le terme «vision de près» utilisé dans l'ISO 11979-9:2006 inclut la vision utile à une distance déterminée, pour laquelle une amélioration est attendue, par exemple de près et/ou à distances intermédiaires.
Očesni vsadki (implantati) - Intraokularne leče - 9. del: Večgoriščna intraokularna stekla (ISO 11979-9:2006)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 11979-9:2006
01-december-2006
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Ophthalmic implants - Intraocular lenses - Part 9: Multifocal intraocular lenses (ISO
11979-9:2006)
Ophthalmische Implantate - Intraokularlinsen - Teil 9: Multifokale Intraokularlinsen (ISO
11979-9:2006)
Implants ophtalmiques - Lentilles intraoculaires - Partie 9: Lentilles intraoculaires
multifocales (ISO 11979-9:2006)
Ta slovenski standard je istoveten z: EN ISO 11979-9:2006
ICS:
11.040.70 Oftalmološka oprema Ophthalmic equipment
SIST EN ISO 11979-9:2006 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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EUROPEAN STANDARD
EN ISO 11979-9
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2006
ICS 11.040.70
English Version
Ophthalmic implants - Intraocular lenses - Part 9: Multifocal
intraocular lenses (ISO 11979-9:2006)
Implants ophtalmiques - Lentilles intraoculaires - Partie 9: Ophthalmische Implantate - Intraokularlinsen - Teil 9:
Lentilles intraoculaires multifocales (ISO 11979-9:2006) Multifokale Intraokularlinsen (ISO 11979-9:2006)
This European Standard was approved by CEN on 19 August 2006.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11979-9:2006: E
worldwide for CEN national Members.
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EN ISO 11979-9:2006 (E)
Foreword
This document (EN ISO 11979-9:2006) has been prepared by Technical Committee ISO/TC 172
"Optics and optical instruments" 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 March 2007, and conflicting national
standards shall be withdrawn at the latest by March 2007.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary,
Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Endorsement notice
The text of ISO 11979-9:2006 has been approved by CEN as EN ISO 11979-9:2006 without any
modifications.
2
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INTERNATIONAL ISO
STANDARD 11979-9
First edition
2006-09-01
Ophthalmic implants — Intraocular
lenses —
Part 9:
Multifocal intraocular lenses
Implants ophtalmiques — Lentilles intraoculaires —
Partie 9: Lentilles intraoculaires multifocales
Reference number
ISO 11979-9:2006(E)
©
ISO 2006
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ISO 11979-9:2006(E)
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ii © ISO 2006 – All rights reserved
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ISO 11979-9:2006(E)
Contents Page
Foreword. iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Physical requirements. 2
4.1 General. 2
4.2 Tolerances and dimensions . 2
5 Optical requirements. 2
5.1 General. 2
5.2 Dioptric power. 2
5.3 Imaging quality. 2
5.4 Additional optical characterization. 3
6 Clinical investigation. 3
6.1 General. 3
6.2 Additional requirements for the clinical investigation plan . 4
7 Information supplied by the manufacturer .4
Annex A (normative) Optical characterization . 6
Annex B (informative) Clinical investigation . 8
Annex C (informative) Determination of sample sizes for the clinical investigation . 16
Bibliography . 20
© ISO 2006 – All rights reserved iii
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ISO 11979-9:2006(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 11979-9 was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 7,
Ophthalmic optics and instruments.
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 2006 – All rights reserved
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INTERNATIONAL STANDARD ISO 11979-9:2006(E)
Ophthalmic implants — Intraocular lenses —
Part 9:
Multifocal intraocular lenses
1 Scope
This part of ISO 11979 is applicable to any intraocular lens whose optic provides two or more rotationally
symmetric powers and whose primary indication is the correction of aphakia with the added benefit of useful
vision at more than one distance (e.g. far and near).
NOTE The term “near vision” as used in this part of ISO 11979 includes useful vision at a distance of claimed benefit;
e.g. near and/or intermediate distances.
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
ISO 11979-3, Ophthalmic implants — Intraocular lenses — Part 3: Mechanical properties and test methods
ISO 11979-4, Ophthalmic implants — Intraocular lenses — Part 4: Labelling and information
ISO 11979-7, Ophthalmic implants — Intraocular lenses — Part 7: Clinical investigations
ISO 14155-1, Clinical investigation of medical devices for human subjects — Part 1: General requirements
ISO 14155-2, Clinical investigation of medical devices for human subjects — Part 2: Clinical investigation
plans
ISO 14971, Medical devices — Application of risk management to medical devices
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11979-1, ISO 14155-1 and
ISO 14155-2 apply.
© ISO 2006 – All rights reserved 1
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ISO 11979-9:2006(E)
4 Physical requirements
4.1 General
This clause is applicable to the physical properties of multifocal intraocular lenses (MIOLs) in the assembled
or final form, as intended for implantation in the human eye.
4.2 Tolerances and dimensions
For tolerances and dimensions, the requirements of ISO 11979-3 apply, together with the following additional
requirement that the manufacturer shall establish tolerances with respect to the optical design.
5 Optical requirements
5.1 General
This clause is applicable to the optical properties and performance requirements of MIOLs in their final form,
as intended for implantation in the human eye.
5.2 Dioptric power
For dioptric power, ISO 11979-2 applies to the far power of an MIOL and to any distinct near power(s).
Two alternative methods for the determination of dioptric power, given in ISO 11979-2, can be applied to
MIOLs. For each near image plane, these methods are modified as follows:
a) for the determination of dioptric power from measured back focal length, once the microscope is focused
on the far image plane and the distance from the back vertex of the MIOL to the distant focal point is
determined, focus the microscope on the near image plane and determine the distance from the back
vertex of the MIOL to the near focal point;
b) for the determination of dioptric power from measured magnification, once the microscope is focused on
the far image plane and the linear dimension, h , in the image is determined, focus the microscope on
image
the near image plane and determine the linear dimension, h , in the image.
image
Depending on the MIOL optic design the correction formulas given in ISO 11979-2 could be invalid. In such
cases, the manufacturer shall derive and justify corrections that result in dioptric powers that are consistent
with power labelling of monofocal IOLs.
If the focusing conditions of ISO 11979-2 are not appropriate for the particular design, another focusing
condition shall be developed with justification.
5.3 Imaging quality
The imaging quality shall be evaluated for the far power and any claimed near power(s) or power range. The
imaging quality specifications apply in all meridians.
For designs that have no distinct near power, a specification describing the through-focus response
performance shall be developed.
The manufacturer shall demonstrate that all available powers meet the imaging quality specifications.
The imaging quality of a MIOL shall be evaluated by modulation transfer function (MTF) testing in the eye
model described in ISO 11979-2 with the following additions:
2 © ISO 2006 – All rights reserved
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ISO 11979-9:2006(E)
ISO 11979-2 is modified such that best focus for the power under evaluation is obtained by maximizing the
MTF at 50 cycles/mm with a (3 ± 0,25) mm aperture. Using that focus, record the MTF values at the following
conditions:
a) small aperture (2 mm to 3 mm), 25 cycles/mm and 100 cycles/mm, for the far power;
b) small aperture (2 mm to 3 mm), 25 cycles/mm and 100 cycles/mm, for the near power(s) or power range;
c) large aperture (4 mm to 5 mm), 25 cycles/mm and 50 cycles/mm, for the far power.
The converging beam from the model cornea described in ISO 11979-2 exposes a central diameter of the
MIOL (± 0,1 mm) to, interchangeably, either the small or the large aperture that is chosen to best control the
MTF performance.
In order to best control the MTF performance of the MIOL, the small and large apertures used for testing shall
be chosen and defined for the lens model over the range of apertures provided above with a tolerance of
± 0,25 mm. The manufacturer shall have the option of setting the minimum MTF specification based on the
area under the curve between the two spatial frequencies or on the MTF value for each individual spatial
frequency.
The minimum MTF specification shall be set such that it results in acceptable visual outcome, verifiable, or to
be verified, by clinical data.
NOTE 1 The minimum MTF specification is typically set as the mean value minus an acceptable level of deviation, e.g.
mean value minus two standard deviations.
NOTE 2 The apertures above represent the exposed diameter of the test MIOL and can differ from the aperture stop of
the optical bench.
NOTE 3 It can be necessary to have a different imaging quality specification for each combination of test aperture and
focus.
5.4 Additional optical characterization
5.4.1 Optical design
Tests that shall be performed to characterize the MIOL optical design are described in Annex A.
5.4.2 Spectral transmittance
For spectral transmittance, ISO 11979-2 applies.
6 Clinical investigation
6.1 General
If clinical evaluation, in accordance with ISO 14155-1, together with risk assessment, in accordance with
ISO 14971, identifies the need for a clinical investigation, the requirements of ISO 14155-1, ISO 14155-2 and
ISO 11979-7 apply, with additional requirements given in 6.2.
NOTE Considerations for the risk analysis regarding modifications to one or more existing designs are found in
[1]
ISO/TR 22979 .
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ISO 11979-9:2006(E)
6.2 Additional requirements for the clinical investigation plan
The requirements for the clinical investigation plan of ISO 11979-7 apply. In addition to the study variables
given in ISO 11979-7, the following shall be considered:
a) near visual acuity (VA), with best distance correction;
b) uncorrected near VA;
c) uncorrected distance VA;
d) quality of vision survey;
e) defocus evaluation;
f) fundus visualization;
g) contrast sensitivity;
h) functional performance.
NOTE 1 Information regarding a design of the clinical investigation can be found in Annex B.
NOTE 2 Information regarding determination of sample sizes for the clinical investigation is provided in Annex C.
7 Information supplied by the manufacturer
The requirements for the information supplied by the manufacturer given in ISO 11979-4 apply, with the
following additional information that shall be made available to the user:
a) a summary of the results of the clinical investigation, if any;
b) a graph of the MTF through focus response performance of the MIOL in the model eye, using the
conditions described in Annex A of this part of ISO 11979 (see example in Figure 1); informative text shall
accompany the figure explaining that the MTF values in the graph describe the MIOL optical performance
in a standardized model eye at 50 cycles/mm as the focus is gradually shifted from that of a far object to
increasingly nearer objects and that higher numbers indicate better performance;
c) a graph of the spectral transmittance through the MIOL in the range of 300 nm to 1 100 nm.
The general requirements for information provided by the manufacturer with medical devices specified in
[2]
EN 1041 should be considered. Symbols can be used instead of text, where appropriate. When symbols
[3] [4]
are used, the requirements of ISO 15223 and EN 980 should be considered.
4 © ISO 2006 – All rights reserved
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ISO 11979-9:2006(E)
Key
X defocus (dioptres)
Y modulation ratio at 50 cycles/mm
1 far object
2 near object
3 3 mm pupil size
4 2 mm pupil size
5 4,5 mm pupil size
Figure 1 — Example of MTF through focus response for multiple pupil sizes
© ISO 2006 – All rights reserved 5
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ISO 11979-9:2006(E)
Annex A
(normative)
Optical characterization
A.1 Theoretical evaluation
Make a theoretical evaluation of, or measure, the percentage of light energy going to the images produced by
the far power and by each near power (or power range) as a function of aperture from 2,0 mm to 4,5 mm at
maximum intervals of 0,5 mm, for the cases when the lens is centred, decentred 0,5 mm, and decentred
1,0 mm. When determining the percentage of light energy going to each of the images, include any
unrefracted light, and any other light that does not usefully contribute to the intended image, in the total light
energy. Report the results in the form of separate graphs for each case.
A.2 Optical testing
This testing will confirm that the actual performance of the lens is similar to its theoretical performance.
Use ten representative samples each of low, medium and high power manufactured MIOLs for testing in the
model eye defined in ISO 11979-2 with the following additions.
a) Modulation transfer function (MTF) testing:
Generate MTF through-frequency curves at different apertures for the images formed by the far power
and by each near power (or power range) with the lens on-axis, decentred 1,0 mm, and tilted 5°. Do this
for aperture sizes 2 mm, 3 mm, and 4,5 mm (± 0,25 mm) at the position of the lens. Focus to give
maximum modulation ratio for 50 cycles/mm in each case. Report the results in the form of graphs,
averaging MTF on-axis curves for each power tested.
For this MTF testing, ten representative samples each of low, medium and high power manufactured
MIOLs are used for the on-axis condition. Each MIOL with the median performance for the on-axis
condition from the low, medium and high power groups are used for the subsequent decentred and tilted
conditions. Therefore, a total of 30 lenses (10 low, 10 medium, and 10 high power) are used for the on-
axis condition, and a total of 3 lenses (1 low, 1 medium, and 1 high power) are used for the decentred
and tilted conditions.
In each case, the performance should be compared to that of a similar monofocal lens.
b) MTF through-focus-response testing:
Generate the MTF through-focus-response of the MIOL at 50 cycles/mm with 2 mm, 3 mm, and
4,5 mm ± 0,25 mm apertures. Focus to maximum MTF at 50 cycles/mm for an object at infinity and then
measure MTF at positions in image space that correspond with increasingly closer object distances down
to that corresponding with 20 cm.
c) Recovery of properties following simulated surgical manipulation:
The testing in this clause applies only to lenses for which the optic is intended to be folded or compressed
during implantation. ISO 11979-3 applies with the following additions.
To evaluate the combined effects of haptic compression and folding and/or injection, as applicable, first
simulate implantation using the maximum recommended time for the MIOL to be held in the folder/injector,
and then place the lens in a holder that constrains the haptics to 10 mm diameter (for posterior chamber
MIOLs) or the minimum expected constrained diameter (for anterior chamber MIOLs).
6 © ISO 2006 – All rights reserved
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ISO 11979-9:2006(E)
Immerse the lens in its holder in aqueous at 35 °C for a minimum of 24 h. Then, while maintaining the
constraint, place the lens in the model eye. Thereafter focus to maximum MTF at 50 cycles/mm and
measure through-frequency MTF. Do this for apertures of 3 mm and 4,5 mm at the positions of the lens.
Report the results in the form of a graph averaging the through frequency MTF of the lenses measured.
The maximum recommended time for the MIOL to be held in the folder/injector is stated in the report.
© ISO 2006 – All rights reserved 7
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ISO 11979-9:2006(E)
Annex B
(informative)
Clinical investigation
B.1 Objectives
The objectives of the clinical investigation are to determine the safety and performance of the MIOL. The
recommended primary safety endpoint is the evaluation of the secondary surgical reintervention rate related to
the optical properties of the MIOL. The null hypothesis is that the study rate minus the control rate is greater
than or equal to the minimally detectable difference between the two rates. The alternative hypothesis is that
the study rate minus the control rate is less than the minimally detectable difference between the two rates.
Annex C of this part of ISO 11979 contains statistical recommendations for determination of the sample size
to test this hypothesis.
B.2 Design
The type of clinical investigation recommended is an unmasked, controlled, comparative study. The safety
variables that are common to ISO 11979-7 are compared to the safety and performance endpoints described
in ISO 11979-7.
A study duration of one year is recommended to adequately evaluate the secondary surgical reintervention
rate related to the optical properties of the MIOL.
B.3 Subjects
B.3.1 Study group
Approximately 420 study subjects are enrolled in the study, in order to obtain complete follow-up on at least
300 study subjects.
Since many of the clinical evaluations for study subjects are performed binocularly, a minimum of 150 study
subjects are implanted bilaterally with the study device.
B.3.2 Control group
Approximately 210 control subjects are enrolled in the study, in order to obtain complete follow-up on at least
150 control subjects. Control subjects receive monofocal IOLs. The monofocal IOL is identified in the clinical
investigation plan (CIP).
All the control subjects are implanted bilaterally with the control device.
B.3.3 Inclusion and exclusion criteria
B.3.3.1 General
Use the same inclusion and exclusion criteria for study and control subjects normally applied for investigations
of intraocular lenses. In addition, consider the criteria given in B.3.3.2 and B.3.3.3.
8 © ISO 2006 – All rights reserved
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ISO 11979-9:2006(E)
B.3.3.2 Inclusion criteria
Include subjects with clear intraocular media other than cataract.
B.3.3.3 Exclusion criteria
Exclude the following subjects:
a) subjects with ocular disorders, other than cataract, that could potentially cause future acuity losses to a
level of 0,66 or worse in either eye;
b) subjects who are expected to require retinal laser treatment;
c) greater than one dioptre of pre-operative corneal astigmatism;
d) inability to achieve secure lens placement in the designated location.
B.3.4 Enrolment of subjects
To minimize the risks associated with the clinical investigation, subject enrolment should occur in stages. The
data from each stage are evaluated and found acceptable by the sponsor and the principal investigator(s)
prior to proceeding to the next stage.
The following phased enrolment plan is recommended:
a) Phase I: 10 subjects, followed for 30 days to 60 days (Form 3);
b) Phase II: 75 additional subjects, followed for 120 days to 180 days (Form 4);
c) Phase III: remainder of subjects.
NOTE 1 Previous clinical experience, i.e. well-documented results from clinical studies, can be used to justify faster
enrolment.
NOTE 2 In cases where the MIOL design depends upon bilateral implantation, and if the monofocal analog of the MIOL
has previously been demonstrated to have performed adequately, bilateral implantation of the MIOL can begin in the initial
phase of the study.
B.4 Variables to be investigated
B.4.1 General
Table B.1 contains a recommended examination schedule, including clinical evaluations to be performed,
number of study and control subjects to be tested, whether the clinical evaluation is done monocularly or
binocularly, and at which visit the clinical evaluation is performed. For reporting periods, see ISO 11979-7.
In addition to the variables in ISO 11979-7, the following variables are evaluated on all study and control
subjects:
a) near visual acuity;
b) pupil size;
c) subject survey.
© ISO 2006 – All rights reserved 9
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ISO 11979-9:2006(E)
The following evaluations are done on a smaller sample of best-case study and control subjects (see
Table B.1 and Annex C of this part of ISO 11979 for recommended sample sizes):
⎯ defocus curves,
⎯ fundus visualization,
⎯ contrast sensitivity, and
⎯ functional performance.
B.4.2 Visual acuity
B.4.2.1 General
Best spectacle corrected distance visual acuity (photopic illumination), near visual acuity with distance
correction (photopic and mesopic illumination), uncorrected distance visual acuity (photopic illumination), and
uncorrected near visual acuity (photopic illumination) are measured. The visual acuity method referenced in
ISO 11979-7 (i.e. Snellen) is not recommended. Rather, ETDRS is the preferred method.
Distance and near visual acuity charts, chart illumination, ambient illumination, testing distances and testing
procedures are standardized for all investigators. The design of the visual acuity chart and testing procedures
[5]
with scoring method are described by Ferris .
B.4.2.2 Luminance
2 2 2
Use a chart luminance of about 85 cd/m (80 cd/m to 160 cd/m acceptable range) for photopic conditions.
2
Use a chart luminance of about 3 cd/m for mesopic conditions. Try to achieve the same luminance at all
testing centres. Ambient illumination is kept from dim to dark. No surface (including reflective surfaces) within
the subject’s field of view is to e
...
SLOVENSKI oSIST prEN ISO 11979-9:2005
PREDSTANDARD
maj 2005
Očesni vsadki (implantati) - Intraokularne leče - 9. del: Večgoriščna stekla
(ISO/DIS 11979-9:2005)
Ophthalmic implants - Intraocular lenses - Part 9: Multifocal lenses (ISO/DIS 11979-
9:2005)
ICS 11.040.70 Referenčna številka
oSIST prEN ISO 11979-9:2005(en)
© Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno
---------------------- Page: 1 ----------------------
EUROPEAN STANDARD
DRAFT
prEN ISO 11979-9
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2005
ICS
English version
Ophthalmic implants - Intraocular lenses - Part 9: Multifocal
lenses (ISO/DIS 11979-9:2005)
Implants ophtalmiques - Lentilles intraoculaires - Partie 9:
Lentilles multifocales (ISO/DIS 11979-9:2005)
This draft European Standard is submitted to CEN members for parallel enquiry. It has been drawn up by the Technical Committee
CEN/TC 170.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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 Management Centre has the same
status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
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© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN ISO 11979-9:2005: E
worldwide for CEN national Members.
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prEN ISO 11979-9:2005 (E)
Foreword
This document (prEN ISO 11979-9:2005) has been prepared by Technical Committee ISO/TC
172 "Optics and optical instruments" in collaboration with Technical Committee CEN/TC 170
"Ophthalmic optics", the secretariat of which is held by DIN.
This document is currently submitted to the parallel Enquiry.
Endorsement notice
The text of ISO 11979-9:2005 has been approved by CEN as prEN ISO 11979-9:2005 without
any modifications.
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DRAFT INTERNATIONAL STANDARD ISO/DIS 11979-9
ISO/TC 172/SC 7 Secretariat: DIN
Voting begins on: Voting terminates on:
2005-03-17 2005-08-17
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION • МЕЖДУНАРОДНАЯ ОРГАНИЗАЦИЯ ПО СТАНДАРТИЗАЦИИ • ORGANISATION INTERNATIONALE DE NORMALISATION
Ophthalmic implants — Intraocular lenses —
Part 9:
Multifocal lenses
Implants ophtalmiques — Lentilles intraoculaires —
Partie 9: Lentilles multifocales
ICS 11.040.70
ISO/CEN PARALLEL ENQUIRY
The CEN Secretary-General has advised the ISO Secretary-General that this ISO/DIS covers a subject
of interest to European standardization. In accordance with the ISO-lead mode of collaboration as
defined in the Vienna Agreement, consultation on this ISO/DIS has the same effect for CEN
members as would a CEN enquiry on a draft European Standard. Should this draft be accepted, a
final draft, established on the basis of comments received, will be submitted to a parallel two-month FDIS
vote in ISO and formal vote in CEN.
In accordance with the provisions of Council Resolution 15/1993 this document is circulated in
the English language only.
Conformément aux dispositions de la Résolution du Conseil 15/1993, ce document est distribué
en version anglaise seulement.
To expedite distribution, this document is circulated as received from the committee secretariat.
ISO Central Secretariat work of editing and text composition will be undertaken at publication
stage.
Pour accélérer la distribution, le présent document est distribué tel qu'il est parvenu du
secrétariat du comité. Le travail de rédaction et de composition de texte sera effectué au
Secrétariat central de l'ISO au stade de publication.
THIS DOCUMENT IS A DRAFT CIRCULATED FOR COMMENT AND APPROVAL. IT IS THEREFORE SUBJECT TO CHANGE AND MAY NOT BE
REFERRED TO AS AN INTERNATIONAL STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS BEING ACCEPTABLE FOR INDUSTRIAL, TECHNOLOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN NATIONAL REGULATIONS.
© International Organization for Standardization, 2005
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ISO/DIS 11979-9
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©
ii ISO 2005 – All rights reserved
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ISO/DIS 11979-9
Contents Page
Foreword. v
1 Scope. 1
2 Normative references. 1
3 Terms and definitions. 1
4 Physical requirements. 1
4.1 General. 1
4.2 Tolerances and dimensions. 2
5 Optical requirements. 2
5.1 General. 2
5.2 Dioptric power. 2
5.3 Imaging quality. 2
5.4 Additional optical characterization. 3
5.4.1 Optical design. 3
5.4.2 Spectral transmittance. 3
6 Clinical investigation. 3
6.1 General. 3
6.2 Additional requirements for the clinical investigation plan . 3
7 Information supplied by the manufacturer . 4
Annex A (normative) Optical characterization . 6
A.1 Theoretical evaluation. 6
A.2 Optical testing. 6
Annex B (informative) Clinical investigation . 8
B.1 Objectives. 8
B.2 Design. 8
B.3 Subjects. 8
B.3.1 Study group. 8
B.3.2 Control group. 8
B.3.3 Inclusion and exclusion criteria . 8
B.3.4 Enrollment of subjects . 9
B.4 Variables to be investigated . 9
B.4.1 General. 9
B.4.2 Visual acuity. 10
B.4.3 Pupil size. 10
B.4.4 Subject survey. 11
B.4.5 Fundus visualization. 11
B.4.6 Defocus evaluation. 11
B.4.7 Far contrast sensitivity. 11
B.4.8 Functional performance. 12
B.5 Data analyses. 13
B.5.1 General. 13
B.5.2 Refractive and adverse events. 14
B.5.3 Functional performance. 14
Annex C (informative) Determination of sample sizes for the clinical investigation . 16
C.1 Definition of symbols . 16
C.2 Sample size guidance for safety and performance evaluation. 16
C.3 Sample size guidance for substudies. 17
C.3.1 Contrast sensitivity substudy . 18
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ISO/DIS 11979-9
C.3.2 Functional performance substudy. 18
Bibliography . 19
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ISO/DIS 11979-9
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 11979-9 was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 7,
Ophthalmic optics and instruments.
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 lenses
Part 10: Phakic intraocular Lenses
This standard contains three Annexes. Annex A is normative. Annexes B and C are informative.
© ISO 2005 – All rights reserved v
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DRAFT INTERNATIONAL STANDARD
ISO/DIS 11979-9
INTERNATIONAL STANDARD
Ophthalmic implants — Intraocular lenses — Part 9: Multifocal
lenses
1 Scope
This standard applies to any intraocular lens whose optic provides two or more rotationally symmetric powers
and whose primary indication is the correction of aphakia with the added benefit of useful vision at more than
one distance (e.g., distance and near).
NOTE The term “near vision” as used in this standard includes useful vision at a distance of claimed benefit; e.g.,
near and/ or intermediate distances.
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
ISO 11979-3, Ophthalmic implants – Intraocular lenses – Part 3: Mechanical properties and test methods
ISO 11979-4, Ophthalmic implants – Intraocular lenses – Part 4: Labelling and information
ISO 11979-7, Ophthalmic implants – Intraocular lenses – Part 7: Clinical investigations
ISO 14155-1, Clinical investigation of medical devices – Part 1: General requirements
ISO 14155-2, Clinical investigation of medical devices – Part 2: Clinical investigation plans
ISO 14971-1, Medical devices – Risk management – Part 1: Application of risk analysis
3 Terms and definitions
For the purposes of this document the definitions given in ISO 11979-1, ISO 14155-1 and ISO 14155-2 apply.
4 Physical requirements
4.1 General
This section applies to the physical properties of multifocal intraocular lenses (MIOLs) in the assembled or
final form, as intended for implantation in the human eye.
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ISO/DIS 11979-9
4.2 Tolerances and dimensions
The requirements of ISO 11979-3 shall apply, together with the following additional requirement:
The manufacturer shall establish tolerances with respect to the optical design.
5 Optical requirements
5.1 General
This section applies to the optical properties and performance requirements of MIOLs in their final form, as
intended for implantation in the human eye.
5.2 Dioptric power
ISO 11979-2 shall apply to the far dioptric power of an MIOL and any distinct near power(s).
Two alternative methods for the determination of dioptric power, given in ISO 11979-2, can be applied to
MIOLs. For each near image plane, these methods are modified as follows:
a) Determination of dioptric power from measured back focal length:
After the microscope is focused on the distant image plane and the distance from the back vertex of
the MIOL to the distant focal point is determined, the microscope is focused on the near image plane
and the distance from the back vertex of the MIOL to the near focal point is determined.
b) Determination of dioptric power from measured magnification:
After the microscope is focused on the distant image plane and the linear dimension, h in the
image,
image is determined, the microscope is focused on the near image plane and the linear dimension,
h in the image is determined.
image,
Depending on the MIOL optic design the correction formulas given in ISO 11979-2 could be invalid. In such
cases the manufacturer shall derive and justify corrections that result in dioptric powers that are consistent
with power labeling of monofocal IOLs.
If the focusing conditions of ISO 11979-2 are not appropriate for the particular design, another focusing con-
dition shall be developed with justification.
5.3 Imaging quality
The imaging quality shall be evaluated for the far power and any claimed near power(s) or power range. The
imaging quality specifications shall apply in all meridians.
For designs that have no distinct near power, a specification describing the through-focus response perfor-
mance shall be developed.
The manufacturer shall demonstrate that all available powers meet the imaging quality specifications.
The imaging quality of a MIOL shall be evaluated by modulation transfer function (MTF) testing in the eye
model described in ISO 11979-2 with the following additions:
The converging beam from the model cornea described in ISO 11979-2 exposes a central diameter of the
MIOL (± 0,1 mm) to, interchangeably, either the small or the large aperture that was chosen to best control the
MTF performance.
ISO 11979-2 is modified such that best focus for the power under evaluation is obtained by maximizing the
MTF at 50 c/mm with a 3 mm aperture. Using that focus, record the following MTF values:
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ISO/DIS 11979-9
a) small aperture (2 mm to 3 mm), 25 c/mm and 100 c/mm, for the far power
b) small aperture (2 mm to 3 mm), 25 c/mm and 100 c/mm, for the near power(s) or power range
c) large aperture (4 mm to 5 mm), 25 c/mm and 50 c/mm, for the far power
In order to best control the MTF performance of the MIOL, the small and large apertures used for testing shall
be chosen and defined for the lens model over the range of apertures from 2 mm to 5 mm with a tolerance of
± 0,25 mm. The manufacturer shall have the option of setting the minimum MTF specification based on the
area under the curve between the 2 spatial frequencies or on the MTF value for each individual spatial fre-
quency.
The minimum MTF specification shall be set such that it results in acceptable visual outcome, verifiable, or to
be verified, by clinical data.
NOTE 1 The minimum MTF specification is typically set as the mean value minus an acceptable level of standard
deviation, e.g. mean value minus 2 standard deviations.
NOTE 2 The apertures above represent the exposed diameter of the test MIOL and can differ from the aperture stop of
the optical bench.
NOTE 3 It can be necessary to have a different imaging quality specification for each combination of test aperture and
focus.
5.4 Additional optical characterization
5.4.1 Optical design
Tests that shall be performed to characterize the MIOL optical design are described in Annex A of this
document.
5.4.2 Spectral transmittance
ISO 11979-2 shall apply.
6 Clinical investigation
6.1 General
If clinical evaluation, in accordance with ISO 14155-1, together with risk assessment, in accordance with
ISO 14971-1, identifies the need for a clinical investigation, the requirements of ISO 14155-1, ISO 14155-2
and ISO 11979-7 shall apply, with additional requirements given below.
NOTE Considerations for the risk analysis regarding modifications to one or more existing designs are found in
ISO TR 22979 [1].
6.2 Additional requirements for the clinical investigation plan
The requirements of ISO 11979-7 shall apply. In addition to the study variables given in ISO 11979-7, the
following shall be considered:
a) near visual acuity (VA), with best distance correction;
b) uncorrected near VA;
c) uncorrected distance VA;
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ISO/DIS 11979-9
d) quality of vision survey;
e) defocus evaluation;
f) fundus visualization;
g) contrast sensitivity; and,
h) functional performance.
NOTE 1 In cases where the MIOL design depends upon bilateral implantation, and if the monofocal analog of the MIOL
has previously been demonstrated to have performed adequately, bilateral implantation of the MIOL can begin in the initial
phase of the study.
NOTE 2 Information regarding a design of the clinical investigation can be found in Annex B of this document.
NOTE 3 Information regarding determination of sample sizes for the clinical investigation are provided in Annex C of
this document.
7 Information supplied by the manufacturer
The requirements of ISO 11979-4 shall apply, with the following additional information that shall be made
available to the user:
a) a summary of the results of the clinical investigation, if any
b) a graph of the MTF through focus response performance of the MIOL in the model eye, using the con-
ditions described in Annex A of this standard (see example in Figure 1). Informative text shall accompany
the figure explaining that the MTF values in the graph describe the MIOL optical performance in a
standardized eye model at 50 c/mm as the focus is gradually shifted from that of a far object to
increasingly nearer objects and that higher numbers indicate better performance.
c) a graph of the spectral transmittance through the MIOL in the range of 300 nm to 1100 nm.
NOTE The general requirements for information provided by the manufacturer with medical devices specified in
EN 1041 [2] should be considered. Symbols can be used instead of text, where appropriate. When symbols are used, the
requirements of ISO 15223 [3] and EN 980 [4] should be considered.
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ISO/DIS 11979-9
Key
X defocus (dioptres) 3 3 mm
Y modulation at 50 c/mm 4 2 mm
1 far object 5 4,5 mm
2 near object
Figure 1 — Example of MTF through focus response for multiple pupil sizes
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ISO/DIS 11979-9
Annex A
(normative)
Optical characterization
A.1 Theoretical evaluation
Make a theoretical evaluation of, or measure, the percentage of light energy going to the images produced by
the far power and by each near power (or power range) as a function of aperture from 2,0 mm to 4,5 mm at
maximum intervals of 0,5 mm, for the cases when the lens is centred, decentred 0,5 mm, and decentred
1,0 mm. When determining the percentage of light energy going to each of the images, include any unre-
fracted light, and any other light that does not usefully contribute to the intended image, in the total light
energy. Report the results in the form of separate graphs for each case.
A.2 Optical testing
This testing will confirm that the actual performance of the lens is similar to its theoretical performance.
Use ten representative samples each of low, medium and high power manufactured MIOLs for testing in the
eye model defined in ISO 11979-2 except as noted below.
a) Modulation transfer function (MTF) testing
Generate MTF through-frequency curves at different apertures for the images formed by the far power
and by each near power (or power range) with the lens on-axis, decentred 1,0 mm, and tilted 5°. Do this
for aperture sizes 2 mm, 3 mm, and 4,5 mm (± 0,25 mm) at the position of the lens. Focus to give maxi-
mum MTF for 50 c/mm in each case. Report the results in the form of graphs, averaging MTF on-axis
curves for each power tested.
For this MTF testing, ten representative samples each of low, medium and high power manufactured
MIOLs are used for the on-axis condition. Each MIOL with the median performance for the on-axis condi-
tion from the low, medium and high power groups are used for the subsequent decentred and tilted condi-
tions. Therefore, a total of 30 lenses (10 low, 10 medium, and 10 high power) are used for the on-axis
condition, and a total of 3 lenses (1 low, 1 medium, and 1 high power) are used for the decentred and til-
ted conditions.
NOTE In each case, the performance should be compared to that of a similar monofocal lens.
b) MTF through-focus-response testing
Generate the MTF through-focus-response of the MIOL at 50 c/mm with 2 mm, 3 mm, and
4,5 mm ± 0,25 mm apertures. Focus to maximum MTF at 50 c/mm for an object at infinity and then mea-
sure MTF at positions in image space that correspond with increasingly closer object distances down to
that corresponding with 20 cm.
c) Recovery of properties following simulated surgical manipulation
The testing in this clause applies only to lenses for which the optic is intended to be folded or compressed
during implantation. ISO 11979-3 applies with the following additions:
To evaluate the combined effects of haptic compression and folding and/or injection, as applicable, first
simulate implantation using the maximum recommended time for the MIOL to be held in the folder/injector,
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ISO/DIS 11979-9
and then place the lens in a holder that constrains the haptics to 10 mm diameter (for posterior chamber
MIOLs) or the minimum expected constrained diameter (for anterior chamber MIOLs).
Immerse the lens in its holder in aqueous at 35 °C for a minimum of 24 h. Then, while maintaining the
constraint, place the lens in the eye model. Thereafter focus to maximum MTF at 50 c/mm and measure
through-frequency MTF. Do this for apertures of 3 mm and 4,5 mm at the positions of the lens.
Report results in the form of a graph averaging the lenses measured. The maximum recommended time
for the MIOL to be held in the folder/inj
...
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