BLOG: Contact lenses and stem cells, a pioneering partnership
The prospect of using contact lenses as a vehicle to transport and embed stem cells to repair damaged corneas was one of the on-going studies discussed at BCLA’s March Evening Meeting.
Alex J Shortt, from Moorfields Eye Hospital and the UCL Institute of Ophthalmology, talked about the causes of corneal limbal stem cell deficiency, a severe and blinding condition resulting from damage to the stem cells that generate the corneal epithelium.
He discussed the use of stem cells in repairing ocular damage during his presentation on ‘Cell therapy for corneal disease’, covering innovations, current research and clinical progress.
A team of Italians have pioneered a technique to treat adults with moderate to severe limbal stem-cell deficiency due to ocular burns. It involves transplanting a sheet of viable autologous human corneal epithelial cells from a patient’s healthy eye into the affected eye after removal of the damaged corneal epithelium.
The procedure has achieved successful results, with impressive research published in the prestigious New England Journal of Medicine, and now has a licence from the European Medicines Agency – but the team is now charging £80,000 per treatment.
However, in an extension of the therapy,scientists have had promising results in a contact lens-based technique for expansion and transplantation of autologous epithelial progenitors for ocular surface reconstruction.
Mr Shortt, a leading expert on the subject, spoke about research exploring the technique where a stable transparent corneal epithelium was restored in each patient, with no recurrence of conjunctivalization or corneal vascularization. The results showed a significant improvement in symptom score in all patients and best-corrected visual acuity was also increased in all eyes after the procedure.
He told the evening lecture, which took place on Thursday, March 23, at the Royal College of Surgeons in London, that this method involving contact lenses was an exciting prospect capable of achieving ocular surface rehabilitation.
While this technique holds promise, the real challenge come when treating bilateral patients as 70 per cent of ocular surface disease effects both eyes, for example Stevens-Johnson syndrome, Aniridia and matrix metalloproteinase.
Mr Shortt pointed to research which showed implants only restored parts of the epithelium temporary in these cases, with the major challenge being the body’s immune system rejecting the cells. He compared this to other transplant procedures, as little was known about this technique and how to engineer the body to accept the foreign cells.
Other interesting progress highlighted during the talk included an approach aimed at using cultivated corneal endothelial cells plus a ROCK inhibitor to promote cell adhesion, proliferation, and inhibition of apoptosis of corneal endothelial cells. This had worked well in monkeys but, with five years after clinical trials began on humans, Mr Shortt said a lack of news from this Japanese study was “concerning”.
In conclusion, Mr Shortt summarised that cultivated corneal limbal epithelial stem cells was now a commercialised therapy and cultivated endothelial cells may become the second corneal stem cell therapy. He said many more cell types for other indications are being studied in animal models.
Mr Shortt was awarded his PhD in 2009 after completing a four-year NIHR Clinical Lectureship at the NIHR Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology. Over the past 10 years, Alex’s research has focused on the development of cell therapies for corneal and conjunctival disease. He has recently commenced a prestigious four-year Wellcome Trust Clinician Scientist Award investigating the response of the recipient’s immune system to engrafted stem cells.
Delegates attending the evening meeting received one CET point.