Abstract
Purpose :
Corneal transplantation is prone to failure in severe inflammatory pathologies like burns, ulcers and scars. Alternative strategies are being pursued globally to find better solutions. This study evaluated the long-term safety and efficacy of using a novel minimally invasive technique of delivering allogeneic human limbus-derived mesenchymal/stromal stem cells (hLMSC) to treat potentially blinding superficial corneal diseases.
Methods :
In this registered and approved pilot-clinical trial, limbal biopsies were obtained from human cadaveric corneo-scleral rims, sourced from an accredited eye bank. The hLMSC were isolated using a previously standardized xeno-free ex-vivo cultivation technique. The technique of hLMSC delivery involved: (i) debridement of the corneal epithelium using a dry sponge; (ii) mixing 0.5 million hLMSC in 0.05ml of the sealer protein component of commercially available fibrin sealant and layering it over the bared corneal stroma; (iii) adding 0.05ml of the thrombin component and allowing the two components of the fibrin sealant to gel together; and (iv) placing a bandage contact lens on the eye. The study group recieved prophylactic topical antibiotics without any corticosteroids. The control group received fibrin sealant without cells, along with standard therapy, including topical corticosteroids, as indicated. Both groups were followed up for 2-years post-operatively.
Results :
The study group included 5 eyes each with acute corneal burns, sterile non-healing ulcers and chronic post-keratitis scars. The control group was matched both in terms of numbers, indications and baseline characteristics. At 2 years, when compared to controls, the eyes receiving hLMSC had: (i) greater best corrected visual acuity (P=0.006); (iii) better corneal clarity, evaluated both clinically (P=0.001) and on scheimpflug imaging (P=0.005); and lesser corneal vascularization (P<0.0001), irrespective of the original indication. Only 2 (13.3%) of the 15 eyes receiving hLMSC required a second surgical intervention as compared to 9 of 15 (60%) eyes in the control group (P=0.005).
Conclusions :
This minimally-invasive technique of delivering allogeneic hLMSC was effective in enhancing vision, improving corneal clarity and reducing corneal opacification and vascularization, thus obviating the need for corneal transplantation in eyes with corneal burns, ulcers and scars.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.