Abstract
Purpose :
Conventional corneal transplantation is prone to failure in severe blinding 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 one such approach, using a novel minimally invasive technique to deliver allogeneic limbal stromal stem cells (LSSC) to restore corneal clarity and improve vision.
Methods :
In this pilot-clinical trial, one-clock hour wide limbal biopsies were obtained from human cadaveric corneo-scleral rims. The LSSC were isolated using a previously standardized xeno-free ex-vivo cultivation technique. The technique of LSSC delivery involved: (i) debridement of the corneal epithelium using a dry sponge; (ii) mixing 0.5 million LSSC in 0.05ml of the fibrinogen 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 to gel; and (iv) placing a bandage contact lens on the eye. Patients in the study group were prescribed prophylactic topical antibiotics without any corticosteroids. Patients in the control group received fibrin sealant without cells, along with standard therapy, including topical corticosteroids, as indicated. Both cases and controls were followed up for 1-year 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 and baseline characteristics. At 6-weeks, 3-months, 6-months and 1 year, when compared to controls, the eyes receiving LSSC had: (i) greater UCVA (P<0.03); (ii) greater BCVA (P<0.01); (iii) better corneal clarity, evaluated both clinically (P<0.001) and on scheimpflug imaging (P<0.007); and lesser corneal vascularization (P<0.0001), irrespective of the original indication. Only 1 (6.7%) of the 15 eyes receiving LSSC required a second surgical intervention as compared to 7 of 15 (46.7%) eyes in the control group (P=0.013).
Conclusions :
This minimally-invasive technique of delivering allogeneic LSSC was effective in enhancing vision, improving corneal clarity, reducing corneal opacification and vascularization, thus obviating the need for corneal transplantation in eyes with corneal burns, ulcers and scars.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.