Macular Degeneration is one of the leading causes of blindness, globally. The macula — the region of the retina accountable for central vision is affected by the disorder. When focusing straight ahead, individuals with AMD suffer anomalies and loss of vision.
Recently, a retinal stem cell patch developed by a team of a research group from UC Santa Barbara, the University of Southern California, and the California Institute of Technology are making strides toward FDA approval. The most recent achievement? The findings show that after 2 years, the implant survives, also does not cause any detectable inflammation or immunological rejection, even in the absence of long-term immunosuppression.
The California Project to Cure Blindness – Retinal Pigment Epithelium 1 (CPCB-RPE1) patch, which has been in progress since 2013, comprises a monolayer of human stem cell-derived RPE cells cultivated over an ultrathin membrane of biologically inert parylene. The stem cell patch’s purpose is to repair damaged cells in the retinas of people suffering from age-related macular degeneration.
Great Early Results
The early trials focused on investigating the patch’s efficacy and gathering data on its functionality. In a one-year follow-up study published in the journal Translational Vision Science & Technology last year, the researchers concluded that the procedure they were working to develop to implant the patch could be executed regularly and that the effectiveness of the patch was promising in people with advanced dry AMD.
Early results were encouraging: four of the 15 patients in the first group had a better vision in the treated eye, whereas five had their vision stabilised. The remaining six people’s visual acuity has continued to deteriorate, and the experts are trying to figure out why.
However, the researchers had some other questions that could not have been answered via delegation. Had the cells retained their identities and, thus, function? Is the patch still in place, and are the donor cells still alive? Were there any indicators of immunological rejection, which is a frequent and severe issue for any implant recipient?
To answer their questions, the researchers first had to classify the cells in the patch’s immediate region. The team verified that the cells were RPE donor cells using meticulous labelling and immunoreactivity testing, demonstrating that the cells on the patch had not moved and that the cells were orientated in the ideal, polarised position—an indication that they had retained a healthy, functional shape.
Furthermore, after 2 years, the group discovered that the inclusion of the patch had not resulted in additional disorders linked with implantation, such as the aggressive development of new blood vessels or scar tissues that could induce retinal detachment. They also discovered no clinical signs of inflammation, which can signal an immunological response to foreign cells, even after the patients were taken off immunosuppressants two months after implantation.
After successfully completing the first phase of testing, the group is now preparing to undertake Phase 2, which will precisely evaluate the patch’s effectiveness. They’ve also made enhancements to the patch’s shelf life. This is the first study of its sort, and it shows that RPE cells in the eye may survive and function even in the potentially toxic environment of a sick eye.
Source: UC Santa Barbara, CA