Based on the latest information, the FDA is now advising eyecare providers to periodically evaluate patients implanted with the device for endothelial cell loss and determine if additional action is needed, including removal of the device.
The FDA approved the CyPass stent in July 2016 for use in conjunction with cataract surgery in adults with mild to moderate primary open-angle glaucoma. The approval was based on results of the COMPASS study.
That study demonstrated a significant reduction in intraocular pressure 2 years after surgery in patients who underwent implantation with the stent at the time of cataract surgery relative to patients who underwent cataract surgery alone.
However, an analysis of 5-year post-surgery data from the FDA-mandated post-approval safety study known as COMPASS-XT prompted Alcon to voluntarily pull all versions of the CyPass stent off the market globally, effective August 29, 2018, as reported by Medscape Medical News.
The company advised ophthalmic surgeons to immediately stop implanting the device and return any unused devices to Alcon.
On September 14, 2018, the FDA issued an initial safety communication alerting eyecare providers of the risk of damage to the cells lining the cornea of the eye in people who have the CyPass stent implanted.
The September communication, based on a preliminary review of data from the COMPASS-XT study, cited concerns regarding significant endothelial cell loss and reductions in endothelial cell density (ECD). Since then, the FDA has received additional post-approval study data that confirm and extend the earlier findings:
- At the 5-year follow-up, 27.2 % (44/162) of implanted patients had more than 30% loss in ECD.
- Data suggest a correlation between the amount the CyPass device extends into the anterior chamber of the eye, assessed by the number of visible retention rings on the device, and the rate of endothelial cell loss. Of the patients that had ECD data at both 2 and 5 years after implantation, mean loss in ECD over the 3-year period was 3.1% when no rings were visible (55 patients), 8.4% with one ring visible (65 patients), 21.0% with two rings visible (26 patients), and 31.4% with three rings visible (eight patients).
- Data on surgical intervention to trim CyPass devices that were identified to be in a suboptimal position (that is, more than two retention rings visible) was very limited in the study. As a result, no conclusions could be made regarding the impact of trimming on endothelial cell loss progression.
- The 5-year endothelial cell loss data suggest that the general rate of cell loss does not plateau at 5 years post-implant.
Based on this new information detailed in a safety alert issued October 24, the FDA now advises that all patients who have the CyPass device be evaluated periodically for ECD using specular microscopy until the rate of loss stabilizes.
They further advise that all eyecare providers evaluate all patients with CyPass to assess device positioning by visualization of the number of retention rings visible on the proximal end of the device. Patients with two or more rings visible upon examination should be evaluated for endothelial cell loss as soon as possible.
Based on the ECD levels and other factors such as age and time post-implantation, the surgeon should determine if additional surgical interventions (that is, trimming, repositioning, removal) are appropriate, the FDA said.
Since the September 14 safety communication, the FDA has classified Alcon’s market withdrawal of the CyPass stent as a Class I recall, indicating there is reasonable chance that the product will cause serious health problems.