• Snellen visual acuity [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  
• corneal epithelial integrity and stability [ Time Frame: 6 months ] [ Designated as safety issue: Yes ]
  

• Impression cytology [ Time Frame: 12 months ] [ Designated as safety issue: Yes ]
  
• Extent of retarding recurrent neovascularisation [ Time Frame: 12 months ] [ Designated as safety issue: Yes ]
  

Ocular surface is composed of corneal and conjunctival epithelial cells. Normal cornea is essential for normal vision. Defects in renewal and repair of ocular surface as a result of limbal stem cell deficiency are now known to cause varying ocular surface morbidity including persistent photophobia, repeated and persistent surface breakdown and overt conjunctivalisation of the cornea. Restoring ocular health in these eyes has traditionally been frustrating. Ex vivo cultured limbal epithelial stem cells have been used successfully to treat limbal stem cell deficiency. Ex-vivo limbal stem cell allograft transplantation is achieved by harvesting limbal corneal tissue from donor eyes (either matched living relatives or cadaveric donors). The donor stem cells are obtained by excising a small area of the conjunctiva at the limbus and are a minor procedure. The tissue so obtained is then grown in tissue culture and once the cells have multiplied sufficiently, small sheets are transplanted on to the affected eye(s), backed with an amniotic membrane. The surgery is undertaken under either local or general anesthesia.