Stem cell-based eye repair: a review of current clinical and preclinical studies



regenerating eye tissues to preserve and restore vision vision is a key sense and its loss can bring emotional and physical challenges to the patient's everyday life vision begins in the marvelous organ the eye light enters the eye through the transparent cornea which is a three layered structure planned through the pupil and through the lens which further refract and focuses the light on the retina light is detected by the photoreceptors which convert the light into electrical signals processed through the retinal layers and reach the brain by the retinal ganglion cell axons in the optic nerve humans have a specialized region in the center of the retina called the macula for high acuity vision color sensitive cones are concentrated at the macula rod photoreceptors active and low light populate the periphery damage to any of these eye cells can cause vision loss stem cells are revolutionising our approach to multiple blinding disorders vision can deteriorate in a variety of ways depending on the sequence of cell loss in age-related macular degeneration the layer of retinal pigment epithelium which provides vital support for the photoreceptors degenerates this leads to photoreceptor death and a decline in central vision other eye diseases such as glaucoma retinitis pigmentosa and diabetic retinopathy also cause eventual death of the photoreceptors and other retinal neurons new RPE cells can be generated from pluripotent stem cells or from adult RPE stem cells present in the eye RPE transplants are already in phase one and Phase two clinical trials injected separately as a self suspension or transplanted as a patch of preformed RPE on a scaffold results to date indicate that these products are safe and future studies on larger patient populations will reveal whether they are effective for AMD a significantly greater challenge is to transplant other retinal cells after overcoming many hurdles in manufacturing photoreceptors can now be produced at high purity and have been transplanted into the subretinal space in animal models but challenges remain in achieving photoreceptor integration still progress is being made and we expect photoreceptor transplantation to enter the clinic in the next few years perhaps the greatest challenge is to replace the retinal ganglion cells which has been done in animal models with some success but real hurdles remain to restore their functional connectivity successfully replacing these cells could help patients suffering from core coma some forms of glaucoma occur when the trabecular meshwork becomes dysfunctional this blocks the outflow of aqueous fluid increasing the intraocular pressure and damaging the retinal ganglion cells transplanting trabecular meshwork stem cells could help restore function lower and dragula pressure this approach is currently in preclinical development cataract is a frequent cause of lens cloudiness replacing the lens with an artificial lens after cataract removal is a common and effective procedure however it is less effective for very young patients a recent clinical trial is testing a new way to remove cataracts in infants that preserves the lens epithelial stem cells to improve regeneration ongoing studies will determine its effectiveness in the long term cloudiness in any of the three corneal layers can occur due to disease or injury limbal stem cell transplant repairs the out epithelium and the procedure is already approved in Europe mesenchymal stromal cells and corneal endothelium cells are being explored as regenerative treatments for the other two layers researchers are working on manufacturing these different corneal cells from pluripotent stem cells to provide an abundance cell source we are at a very exciting time in the development of ocular regenerative therapies and yet significant challenges remain for example to obtain functional connectivity and to have the cells integrate well into the retina and to address the immune response to the transplant all of these issues require scientists working together with clinicians and patients to come up with solutions we look forward to a rich pipeline of regenerative therapies for the eye you you

4 comments

  1. Nice visualization, that made it a lot easier to follow despite its many technical terms.

    Unfortunately, despite the good intonation, the audio was rather uncofortable to listen to, due to all the popping noises.
    A pop filter in front of the microphone can solve those issues.

  2. I don't know what fission has to do with with eye biology. On an unrelated note I also don't understand why people confuse microphones and shavers. Besides that- good video!

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