This document specifies minimum requirements for instruments and systems that fall into the class of corneal topographers (CTs). It also specifies tests and procedures to verify that a system or instrument complies with this document and thus qualifies as a CT according to this document. It also specifies tests and procedures that allow the verification of capabilities of systems that are beyond the minimum requirements for CTs.<\/p>\n
This document defines terms that are specific to the characterization of the corneal shape so that they may be standardized throughout the field of vision care.<\/p>\n
This document is applicable to instruments, systems and methods that are intended to measure the surface shape of the cornea of the human eye.<\/p>\n
The measurements can be of the curvature of the surface in local areas, three-dimensional topographical measurements of the surface or other more global parameters used to characterize the surface.<\/p>\n<\/div>\n
This document is not applicable to ophthalmic instruments classified as ophthalmometers.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | National foreword <\/td>\n<\/tr>\n | ||||||
| 4<\/td>\n | European foreword <\/td>\n<\/tr>\n | ||||||
| 6<\/td>\n | Foreword <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | 1 Scope 2 Normative references 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 3.8 Curvature 3.8.1 Axial curvature <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 3.16 Surface 4 Requirements 4.1 Area measured <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 4.2 Measurement sample density 4.3 Measurement and report of performance 4.4 Colour presentation of results 5 Test methods and test devices 5.1 Tests 5.1.1 Accuracy test 5.1.2 Repeatability test 5.2 Test surfaces 5.2.1 Reflection-based and Placido ring corneal topographers 5.2.2 Luminous surface corneal topographer 5.2.3 Optical-sectioning corneal topographer <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 5.2.4 Specification of test surfaces 5.2.5 Verification of test surfaces 5.2.6 Type testing of surfaces <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 5.3 Data collection \u2014 Test surfaces 5.4 Analysis of the data 5.4.1 General <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 5.4.2 Structure of the accuracy data set 5.4.3 Analysis of the paired data sets <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 5.4.4 Report of accuracy performance 6 Accompanying documents 7 Marking <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | Annex A (informative) Test surfaces for corneal topographers (CTs) <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | Annex B (informative) Standardized displays for corneal topographers (CTs) <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | Annex C (normative) Calculation of area-weighting values <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | Annex D (normative) Test methods for measuring human corneas <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Ophthalmic instruments. Corneal topographers<\/b><\/p>\n |