The FDA said international standards were insufficient, and put forth a stricter standard in order to ensure that intraocular lenses and other intraocular ophthalmic devices are free of bacteria upon manufacturing.
Contamination of bacterial endotoxins during the lens manufacturing, sterilization, or packing process can lead to Toxic Anterior Segment Syndrome (TASS), which in turn, can lead to surgical interventions like glaucoma surgery and corneal transplantation, the FDA said in a just-released final guidance on the topic.
Cases of TASS have risen twenty-fold over the past decade from 1 in 1,000 to 2 in 100 devices.
Citing studies, the FDA said the International Standards Organization regulation (dubbed ISO 11979-8) limiting endotoxins to 0.5 endotoxin units per milliliter in IOLs is not tough enough. It recommends a limit of equal to or less than 0.2 endotoxin units per milliliter (EU/mL) for individual devices, regardless of whether it is supposed to be used in the front or back of the eye.
The guidance also spells out the recommended testing regime. Validation using a bacterial endotoxin test should include random samples of lots of the devices spiked to endotoxin levels of 0.1, 0.2, and 0.5 EU/mL. The percentage of endotoxin recovered from the sterilization process should then be calculated for each of the three levels.
The guidance applied to so-called ophthalmic viscosurgical devices, including intraocular lenses, capsular tensions rings, glaucoma devices and phacofragmentation systems. They typical require approval via FDA's stringent PMA pathway.
The FDA also made some recommendations about labeling, saying, "The phrase 'non-inflammatory' in the labeling of an OVD should not be used since the OVD could elicit some inflammation but it may not be clinically significant. OVDs may be labeled as having 'low inflammatory potential' if animal testing or another validated method for detecting inflammation is performed as a product release test."
The guidance is a reminder that the FDA regs remain some of the toughest in the world, and the agency is willing to override international standards if it feels that is necessary to protect patients.
- read the guidance (PDF)