Focus on limbal stem cell deficiency and limbal cell transplantation

Table 1 Causes of limbal stem cell deficiency

Genetic disease	Acquired immune-mediated	Acquired nonimmune-mediated	Others
Congenital aniridia	Steven-Johnson syndrome	Chemical/thermal injury	Ocular surface tumors
Keratitis ichthyosis deafness syndrome	Toxic necrolysis	Radiation injury	Drug-induced LSCD
Xeroderma pigmentosum	Mucous membrane pemphigoid	Contact lens wear	Idiopathic
Ectrodactyly-ectodermal dysplasia-clefting syndrome	Vernal/atopic keratoconjunctivitis	Multiple limbal surgeries
Dyskeratosis congenita	Graft-vs-host disease	Bullous keratopathy
Peter’s anomaly		Chronic lid diseases
		Infectious ocular diseases

LSCD: Limbal stem cell deficiency.

Table 2 Stages of limbal stem cell deficiency

Stage		A	B	C
I	Central 5 mm of cornea not involved	Limbus involvement < 50%	Limbus involvement > 50% but < 100%	Limbus entirely involved
II	Central 5 mm of cornea involved	Limbus involvement < 50%	Limbus involvement > 50% but < 100%
III	The entire corneal surface involved

Table 3 Common surgical techniques for limbal stem cell deficiency

Procedure	Abbreviation	Tissue origin
Direct transplantation
Conjunctival limbal autograft	CLAU	Patient
Living-related conjunctival allograft	lr-CLAL	Relative donor
Keratolimbal allograft	KLAL	Cadaveric donor
Cincinnati procedure		Relative/cadaveric donor
Modified Cincinnati procedure		Patient/cadaveric donor
Stem cells transplantation
Simple limbal epithelium transplantation	SLET	Patient
Tissue engineering
Cultured limbal epithelial transplantation	CLET	Patient/living donor
Autologous conjunctival epithelial cells cultivated ex vivo	EVCAU	Patient
Cultivated oral mucosa epithelial transplantation	COMET	Patient