ISO 16672:2020 pdf download Ophthalmic implants — Ocular endotamponades
4 Intended performance The general requirements for the intended performance of non-active surgical implants specified in ISO 14630 shall apply. This document describes surgically invasive medical devices that are compatible with the internal ocular environment and, through a primary mechanical action, are used to reposition and/or tamponade a detached retina.
They are used either intra-operatively and removed at the end of surgery, as in the case of perfluorocarbon liquids, or are designed to remain in the vitreous cavity until removal at a later date as in the case of silicone oils, or they are completely absorbed as in the case of gaseous OE. The manufacturer shall describe and document the functional characteristics of the OE in terms of its chemical composition and physical properties, the intended surgical applications, the conditions of use and the maximum duration of contact with, and effects upon ocular tissues, with particular regard to safety. All available published standards and published scientific and clinical literature, validated test results, clinical investigations, and pre-clinical and clinical evaluations shall be considered in determining the intended device.
5 Design attributes
5.1 General The general requirements for non-active surgical implants specified in ISO 14630 shall apply. All testing requirements specified below shall be performed with finished and sterilized product, ready for release. Any analytical methods utilized shall be validated. NOTE Tests described herein are intended to apply when qualifying materials and not necessarily as a routine quality assurance/control programme.
5.2 Chemical description and contaminants The manufacturer shall provide a description of each of the components in the finished product, and their respective quality specifications and concentrations.
If the component material is derived from biological sources, the organism from which it is obtained shall be stated along with its source. Whenever possible, for all polymers, the backbone, any side groups and end-groups shall be identified. The identification of potentially hazardous chemical or biological contaminants shall be determined by a risk analysis.
For raw materials of biological origin, these impurities can include proteins, nucleic acids, or other biological materials. Contaminants of the finished product derived from the source materials or from the manufacturing process, such as by-products, residual monomers, cross-linking agents, catalysts, products derived from auto-oxidation processes or from containers transport and packaging that are potentially hazardous either systemically or to the tissues of the eye, shall be identified and quantified, whenever possible, and their concentration in the finished product reported. Limits for identified contaminants shall be set, justified and documented. Testing of the biological effects of these contaminants during evaluation of biological safety may be required if the risk analysis determines it necessary. Chemical changes during transport and storage shall be considered.
Any contaminant being identified to cause, directly or by being the source for other contaminants, considerable harm to the patient, the user or any third party shall be reduced to a level that the health risk associated with the contaminant is considered acceptable. The following list, although not exhaustive, provides some information on likely contaminants of common endotamponade materials: Materials of biological origin may contain proteins, nucleic acids, or other biological materials as contaminants. Perfluorocarbon liquids may contain oxygen containing compounds and incompletely fluorinated contaminants, including HF. Specifically incompletely fluorinated contaminants, including HF, are likely to occur and they bear a high risk for the patient already at the ppm level.
Therefore, the concentration of incompletely fluorinated contaminants, including HF, shall be as low as possible. Different methods can be used for which the specific limits need to be specified based on the risk analysis. In Annex C a method is described for which a level of 10 ppm has been published, to assure material safety in regard of the aforementioned impurities. Silicone oils may contain catalysts, heavy metals, residual monomers and short chain oligomers and polymers as a result from their synthesis. For any liquid OE, control over synthesis of the tamponade material according to applicable standards and monographs and analytically controlled purification procedures according to applicable standards or monographs are minimum requirements.ISO 16672:2020 pdf download