Overview

This standard is applicable to instruments and methods used for measuring the axial length of the human eye. It defines minimum requirements for such instruments and systems and defines test methods and procedures to verify that a system or instrument qualifies as an axial length measuring device in accordance with this International Standard. The measurement of the axial length of the human eye is one of the pre-requisites for the calculation of the necessary power of an artificial lens that is to be implanted in the eye during cataract and/or refractive surgery. Since the 1950s ultrasound biometry instruments have been used for ocular distance measurements. In recent years, optical biometry instruments based on partial coherence interferometry have established themselves as an alternative to echometry. Neither instrument is calibrated against a common standard. As a result, there are systematic differences between measurements taken with different biometers. The resulting errors can directly affect surgical outcomes for patients. The specifications of DIN EN ISO 22665 aim at contributing to synchronize of the known methods of the optical and acoustical axial length measurement. The measurement values in accordance with the standard shall be suitable: - independent of the method on which they are based - by application of the same calculation methods for intraocular lenses without the user having to apply instrument-specific adaptation parameters which has been the case until now. This standard has been prepared by ISO/TC 172/SC 7 "Ophthalmic optics and instruments" in collaboration with CEN/TC 170 "Ophthalmic optics" (both secretariats: DIN, Germany) and with German project management. The responsible committee at DIN is Working Committee NA 027-01-20 AA "Intraokulare Medizinprodukte" ("Intraocular medical devices") at NAFuO.

Document: references other documents

Responsible national committee

NA 027-01-20 AA - Intraocular medical devices  

Responsible european committee

CEN/TC 170 - Ophthalmic optics