Ultraviolet radiation transmission of soft disposable contact lenses and ISO 18369: claims and compliance

Abstract

ABSTRACT Clinical relevance This study was carried out to provide advice to eye care practitioners on those soft disposable contact lenses that comply with the Class 1 or Class 2 requirements of the international standard ISO 18369 for ultraviolet radiation protection. Background This study was carried out to provide advice to eye care practitioners on those soft disposable contact lenses that comply with the Class 1 or Class 2 requirements of the international standard ISO 18369 for ultraviolet radiation (UVR) protection and to validate any claims made. It is intended to be used when a patient needs or requests UVR protection. A revised ISO 18369-3 was published in 2017. There is no Australian adoption nor equivalent. Methods The direct spectral transmittance of three specimens of each of the twenty soft disposable contact lens types available in Australia in 2018 was measured in saline in a quartz cuvette with a dual beam spectrophotometer from 200-780 nm. Transmittance values for each material were averaged and scaled according to a single measurement of its transmittance in the visible spectrum (380-780 nm). Based on the ISO 18369-3:2017 criteria, lens materials were denoted as Class 1, Class 2 or non-UVR protectors. This classification was compared with any claim made by the manufacturer. Results All claims of the manufacturers for Class 1 or Class 2 were valid. There were no examples of any missed opportunity to make a claim. Some claims were so general as to be untestable. Some numerical claims appeared to hide that only a Class 2 claim could be made. Conclusions Claims of Class 1 or Class 2 were found to be appropriate. There were no missed opportunities to claim. UV protection claims that were not in the ISO 18369-3 format may be taken as Class 2 compliance but not Class 1 compliance. A two-class system of UV protectors and non-UV protectors may serve practitioners and their patients better.