1、BSI Standards PublicationBS EN ISO 11979-2:2014Ophthalmic implants Intraocular lensesPart 2: Optical properties and test methodsBS EN ISO 11979-2:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO11979-2:2014. It supersedes BS EN ISO 11979-2:2000 which isw
2、ithdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee CH/172/7, Eye implants.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users a
3、re responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 70881 7ICS 11.040.70Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theSt
4、andards Policy and Strategy Committee on 31 August 2014.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 11979-2 August 2014 ICS 11.040.70 Supersedes EN ISO 11979-2:1999English Version Ophthalmic implants - Intraocular lenses - Part 2: Opt
5、ical properties and test methods (ISO 11979-2:2014) Implants ophtalmiques - Lentilles intraoculaires - Partie 2: Proprits optiques et mthodes dessai (ISO 11979-2:2014) Ophthalmische Implantate - Intraokularlinsen - Teil 2: Optische Eigenschaften und Prfverfahren (ISO 11979-2:2014) This European Stan
6、dard was approved by CEN on 25 July 2014. 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 su
7、ch 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 ow
8、n 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,
9、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 COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORM
10、UNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 11979-2:2014 EBS EN ISO 11979-2:2014EN ISO 11979-2:2014 (E) 3 Foreword This document (EN ISO 11979-2:2014
11、) 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 identica
12、l text or by endorsement, at the latest by February 2015, and conflicting national standards shall be withdrawn at the latest by February 2015. 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 r
13、esponsible for identifying any or all such patent rights. This document supersedes EN ISO 11979-2:1999. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croati
14、a, 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
15、 United Kingdom. Endorsement notice The text of ISO 11979-2:2014 has been approved by CEN as EN ISO 11979-2:2014 without any modification. BS EN ISO 11979-2:2014ISO 11979-2:2014(E) ISO 2014 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and de
16、finitions . 14 Requirements 14.1 General . 14.2 Dioptric power 24.3 Determination of imaging quality 34.4 Spectral transmittance . 5Annex A (normative) Measurement of dioptric power . 6Annex B (normative) Measurement of resolution efficiency .14Annex C (normative) Measurement of MTF .17Bibliography
17、.22BS EN ISO 11979-2:2014ISO 11979-2:2014(E)ForewordISO (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
18、 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 Elect
19、rotechnical 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
20、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 ri
21、ghts. ISO shall not be held responsible for identifying any or all such patent rights.ISO 11979-2 was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 7, Ophthalmic optics and instruments.This second edition cancels and replaces the first edition (ISO 11979-2:1999),
22、which has been technically revised. It also incorporates the Technical Corrigendum ISO 11979-2:1999/Cor.1:2003.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
23、properties and test methods Part 4: Labelling and information Part 5: Biocompatibility Part 6: Shelf-life and transport stability testing Part 7: Clinical investigations Part 8: Fundamental requirements Part 9: Multifocal intraocular lenses Part 10: Phakic intraocular lensesiv ISO 2014 All rights re
24、servedBS EN ISO 11979-2:2014ISO 11979-2:2014(E)IntroductionThis part of ISO 11979 initially addressed monofocal IOLs and now has been revised to include the requirements and test methods for spherical monofocal, aspheric monofocal, toric, multifocal, and accommodative IOLs. This part of ISO 11979 co
25、ntains several test methods for which associated requirements are given and one test method for which no requirement is formulated. The former are directly connected to the optical functions of intraocular lenses. The latter, the test for spectral transmittance, has been provided for information abo
26、ut UV transmission and in specific situations, e.g. when using laser light sources for diagnosis and treatment.For the original spherical monofocal IOLs, extensive interlaboratory testing was carried out before setting the limits specified. During this testing some basic problems were encountered as
27、 described in Reference 1. The accuracy in the determination of dioptric power has an error that is not negligible in relation to the half dioptre steps in which intraocular lenses are commonly labelled. The dioptric power tolerances take this fact into account. Hence the limits set may lead to some
28、 overlap into the next labelled power, especially for high dioptre lenses. Reference 1 gives further discussion on this subject.The majority of lenses hitherto implanted were qualified using the method described in Annex B or Annex C (model eye 1). The method in Annex B is limited in its applicabili
29、ty, however. The limits for the more general method in Annex C have been set in terms of MTF in a model eye, following two approaches. The first is by correlation to the method and limit in Annex B. Further discussion can be found in Reference2. The second is set as a percentage of what is calculate
30、d as theoretical maximum for the design, with the rationale that a minimum level of manufacturing accuracy be guaranteed. For common PMMA lenses, these two limits correspond well with each other. For lenses made of materials with lower refractive index, or with certain shape factors, or for extreme
31、power lenses in general, the latter limit is lower than the former. However, such lenses are already in use, indicating clinical acceptance. The question of which is the absolute lowest limit that is compatible with good vision arises. No definite answer can be found, but following clinical data pre
32、sented to the working group, an absolute lower limit has been set for the calculation method. ISO 2014 All rights reserved vBS EN ISO 11979-2:2014BS EN ISO 11979-2:2014Ophthalmic implants Intraocular lenses Part 2: Optical properties and test methods1 ScopeThis part of ISO 11979 specifies requiremen
33、ts and test methods for certain optical properties of intraocular lenses (IOLs) with any of spherical, aspheric, monofocal, toric, multifocal, and/or accommodative optics. The generic descriptor IOL used throughout this document also includes phakic intraocular lenses (PIOL).2 Normative referencesTh
34、e 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 6328:2000, Photography Photographic materials De
35、termination of ISO resolving powerISO 9334, Optics and photonics Optical transfer function Definitions and mathematical relationshipsISO 9335, Optics and photonics Optical transfer function Principles and procedures of measurementISO 11979-1, Ophthalmic implants Intraocular lenses Part 1: Vocabulary
36、ISO 11979-3, Ophthalmic implants Intraocular lenses Part 3: Mechanical properties and test methodsISO 11979-4, Ophthalmic implants Intraocular lenses Part 4: Labelling and information3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 11979-1 and ISO 9334
37、 apply.4 Requirements4.1 GeneralThe manufacturer shall demonstrate that the entire range of available powers meets the specifications herein. All optical properties apply at in situ conditions, either by being measured at simulated in situ conditions, or being measured at other conditions and then c
38、orrected to in situ conditions.For IOLs where the optic is intended to be deformed during implantation, it shall be demonstrated that dioptric power and imaging quality are retained at in situ conditions or equivalent following surgical manipulation and recovery. See ISO 11979-3 for more detail.The
39、test methods described in this standard are reference methods. Alternative methods that produce equivalent results to those obtained with the reference methods can be used if the manufacturer can demonstrate that the IOLs meet the minimum dioptric power and imaging quality requirements.INTERNATIONAL
40、 STANDARD ISO 11979-2:2014(E) ISO 2014 All rights reserved 1BS EN ISO 11979-2:2014ISO 11979-2:2014(E)4.2 Dioptric power4.2.1 GeneralThe dioptric power of spherical or aspheric lenses as stated by the manufacturer in the IOL labelling shall be within the tolerance limits specified in Table 1. For rot
41、ationally symmetric lenses, these tolerances apply in all meridians.Table 1 Tolerance limits on spherical dioptric power, SNominal spherical dioptric power rangeaDTolerance limits on spherical dioptric powerD0 S 15 0,315 S 25 0,425 S 30 0,530 S 1,0aThe ranges apply to positive as well as negative di
42、optric powers.4.2.2 Dioptric power for toric IOL (TIOL)When determined by any of the methods in Annex A, the dioptric power in the meridians of highest and lowest dioptric power and the spherical equivalent (SE) power shall be within the tolerance limits for dioptric power specified in Table 1. Addi
43、tionally, the cylindrical power calculated as the absolute difference between the powers of the meridian of highest dioptric power and the meridian of lowest dioptric power shall be within the cylindrical power tolerance limits specified in Table 2.Table 2 Tolerance limits on cylindrical dioptric po
44、wer, CNominal cylindrical dioptric power rangeDTolerance limits on cylindrical dioptric powerDSE 25 DTolerance limits on cylindrical dioptric powerDSE 25 D0 C 2,5 0,3 0,42,5 C 4,5 0,4 0,44,5 C 0,5 0,5The TIOL shall have a physical axis indicator such as a mark, engraving, or label that aligns with t
45、he meridian of lowest dioptric power, and is visible to the surgeon during implantation. The angle difference between the physical axis indicator and the meridian with the lowest dioptric power shall be less than or equal to 5,0.4.2.3 Dioptric power for multifocal IOL (MIOL)Methods A.2 to A.4 can be
46、 applied to MIOL for determining the far power and any distinct near powers. When using A.2, dioptric power must be justified as a calculation based only on spherical surfaces. The dioptric power of the far power shall be within the tolerance limits specified in Table 1 and the dioptric power of the
47、 addition power(s) shall be within the tolerances in Table 3.2 ISO 2014 All rights reservedBS EN ISO 11979-2:2014ISO 11979-2:2014(E)Table 3 Tolerance limits on addition dioptric power, ANominal addition dioptric power rangeDTolerance limits on addition dioptric powerDfar power 25 DTolerance limits o
48、n addition dioptric powerDfar power 25 D0 A 2,5 0,3 0,42,5 A 4,5 0,4 0,44,5 A 0,5 0,54.2.4 Dioptric power for accommodating IOL (AIOL)The power associated with the far power configuration of an AIOL shall be determined by one of the methods in Annex A. When determined by one of these methods, the di
49、optric power tolerances specified in Table 1 shall apply to the power associated with the far power configuration of the AIOL. The dioptric change of the lens or system in the eye resulting from the accommodative action shall be determined in a theoretical or laboratory eye model.4.3 Determination of imaging quality4.3.1 GeneralImaging quality is dependent upon compatibility between the optical design and conditions that are used to evaluate optical performance. Imaging q
