Abstract
Purpose: :
Treatment of limbal stem cell deficiency (LSCD) has been achieved by transplantation of cultured limbal stem cells (LSC) taken from a small biopsy of autologous or allogeneic living-related/cadaveric limbus. Allogeneic grafts require immunosuppression and are often unsuccessful in the long-term. In bilateral total LSCD, where there are no LSC, there has been recent interest in the ex vivo expansion of autologous oral mucosal epithelial cells (OMEC) for ocular surface (OS) reconstruction. This study aims to develop and evaluate an animal-free autologous OMEC expansion protocol under GMP conditions to treat patients with bilateral total LSCD.
Methods: :
Cultured autologous OMEC onto human amniotic membrane (HAM) were transplanted into the worst eye of 2 patients with bilateral total LSCD. Main outcome measures: OS reconstruction with corneal epithelialization, improvement in visual acuity, absence of conjunctiva-derived cytokines on impression cytology, pain/vision impairment scores and postoperative complications.
Results: :
Both patients were male, mean age was 60 (range, 44-76). Mean follow up was 29.5 months (range, 23-36). Post-operatively, satisfactory OS reconstruction was obtained in both eyes within 6-10 weeks. HLA matched penetrating keratoplasty (PKP) was performed in both eyes. However, one of the eyes developed recurrent epithelial erosion (REE) post-PKP, requiring frequent use of bandage contact lens. At last examination, visual acuity improved in both eyes, however less significantly in the eye with REE. Vision impairment and pain scores improved in both patients. CK3 was expressed in all but the basal layers, whilst CK19 which is used as a conjunctival marker was notexpressed in the expanded oral epithelium. The CFE and the expression of putative SC markers indicated the presence of epithelial SC in oral mucosa, i.e. p63 was predominantly expressed in the basal layer of the epithelium in both eyes
Conclusions: :
We describe a fully GMP compliant, animal-free method of ex vivo expansion of autologous OMEC to produce a progenitor rich epithelium similar to cornea and therefore suitable for OS reconstruction. Proof of concept was achieved by transplantation of the OMEC/HAM construct into two patients with bilateral total LSCD that resulted in successful reversal of LSCD with increased comfort and improvement of visual acuity in the treated eyes up to 24 months.
Keywords: cornea: epithelium • cornea: clinical science • cornea: basic science