Cells, Genes, Bionic Eyes and Robots – Transformations in Retinal Therapy
The past 10 years have seen true transformations in the tools available to retinal specialists. Following earlier imaging and pharmacological advances, the arrival of new modalities of treatment will mean conditions that have previously been untreatable will now begin to be addressed.
Molecular advances and a better understanding of cell biology have led to a consolidation of the promising results and safety assurances of early trials in gene therapy and seen a significant application to the retina. The original RPE65 gene therapy trial and the subsequent choroideraemia trials will be discussed as an example of this powerful new tool. Similarly, a greater understanding of cellular development biology and advancement in stem cell technology has led to the creation of stable and safe stem cell sources. These include human embryonic stem cells (HESC) as well as adult sources. The challenge more recently has been to transform these stem cells into differentiated cells that are useful for transplantation in disease. Recent publications have shown that it is possible to consistently differentiate all layers of the retina and the RPE from stem cell sources. The main advantage of using a stem cell source is that there is an infinite capacity to reproduce and therefore an infinite capacity to produce cells for transplantation. The availability of retinal cells for transplantation will revolutionise the many diseases that lead to cell loss and which has, to date, rendered then untreatable.
The advent of the artificial retina, in terms of technological advances, has gone from being fiction and experimental to a state where there are three devices with regulatory approval in Europe and one with US FDA approval. These first-generation devices have many limitations in terms of replacing adequately the patients’ visual function but have without doubt shown the feasibility, safety and long-term stability of these devices in the context of severely damaged retinas. As an engineering triumph and a technological advance in bio-electronic interfaces, they remain extra-ordinary and I will discuss their status and future. Finally, the new frontier in retinal surgery is robotic-assisted surgery and independent instrument delivery systems for these exciting new biological treatment modalities. I will introduce this area that is in its infancy but which will likely accelerate leading to change in the operating environment in a major way in the future.