Restoring vision in AMD may be a possibility with stem cell transplantation.
Cell delivery through the suprachoroidal space
In an early uncontrolled, unmasked study of suprachoroidal delivery (Ho et al. Am J Ophthalmol 2017;179:67-80), cells derived from the umbilical cord were delivered to 33 of 35 patients with bilateral dry AMD with geographic atrophy. One year postoperatively, visual gains in the best-corrected visual acuity of 10 or more and 15 or more letters occurred, respectively, in 34.5% (10 of 29 eyes) and 24.1% (7 of 29 eyes) of eyes treated with palucorcel (CNTO-2476, Janssen Biotech) compared with 3.3% (1 of 30 eyes for both) of the untreated fellow eyes. A caveat regarding this study is that the overall results showed that 17.1% of patients had a retinal detachment and 37.1% had retinal perforations, both of which were secondary to the transplantation procedure.
Deriving retinal pigment epithelium (RPE) from pluripotent stem cells
In two recently investigated approaches to using RPE cells, monolayer RPE was derived from the cells and either injected as a suspension or placing them on a biodegradable scaffold. The suspension process is technically simpler and uses a smaller incision, thus creating less damage at the retinotomy with a lower risk of hemorrhage compared with the scaffolding approach, which has the advantage of being a confluent, polarized monolayer.
And when there are advantages, there are also disadvantages. The suspension may not settle in the desired atrophic areas and may not form a monolayer. The scaffold approach is a larger scale surgery that comes with more trauma, potential for hemorrhage and proliferative vitreoretinopathy (PVR), and requires a silicone oil tamponade.
Rajesh Rao, MD
Dr. Rao has no financial interest in any aspect of this report.