Conjunctival limbal autograft (CLAU): In its simplest form, conjunctival limbal autograft has been successfully used in the treatment of unilateral LSCD. However, there is a concern of inducing LSCD in the donor eye, therefore leading to its modification involving a smaller source tissue in conjunction with in vivo expansion. While these methods have been successful for patients with unilateral LSCD, similar approaches with conjunctival limbal allograft (due to bilateral LSCD) have been largely unsuccessful due to high frequency of immune rejection Since the first report in 1989 by Kenyon and Tseng, CLAU has become a widely accepted technique in the management of unilateral total LSCD (Kenyon and Tseng 1989)

Corneal stem cell allograft transplantation: Allograft transplantation for the patients suffering from bilateral total LSCD or whose fellow eye is not suitable as a graft source. Generally, allograft transplantation includes cadaveric keratolimbal allograft (KLAL) and living-related conjunctival limbal allograft (Lr-CLAL) (Shanmuganathan et al. 2007; Huang et al. 2011; Lam et al. 2000; Rao et al. 1999). Due to high risk of immune rejection, both methods offer poor long-term outcomes.

Simple limbal epithelial transplantation (SLET): The use of amniotic membrane for in vivo expansion of smaller graft tissue improved the success rate of limbal epithelial transplant (Meallet et al. 2003; Mittal et al. 2006). Amniotic membrane seems to inhibit inflammation and provide a supportive niche for the transplanted LEST cells. In 2012, Sangwan VS (Sangwan et al. 2012) described this surgical technique. In this procedure, a small 2 × 2 mm strip was removed from the fellow eye and chopped into pieces. Then, the tiny pieces were seeded on the amniotic membrane (AM)-covered cornea. Complete reconstruction with epithelialized, avascular, and stable corneal surface was observed after 6 weeks in all 6 recipient eye.

Corneal Limbal Epithelial Transplant (CLET): The cells used for cultured limbal epithelial transplantation (CLET) are obtained from a relatively small biopsy of limbal tissue. This is grown on a denuded amniotic membrane (Fig. 18.1) which is used as a cell substrate to facilitate transfer of the cells from culture to recipient cornea. Several materials such as fibrin gels (Han et al. 2002; Rama et al. 2001; Talbot et al. 2006), collagen (Dravida et al. 2008; McIntosh Ambrose et al. 2009; Takezawa et al. 2004), keratin films (Borrelli et al. 2013; Feng et al. 2014), silk fibroin films (Bray et al. 2011), chitosan hydrogels (Grolik et al. 2012), siloxane–hydrogel contact lens (Di Girolamo et al. 2007), polystyrene, and nanofiber scaffold (Sharma et al. 2011a) (Figs. 18.2 and 18.3) have been tested as scaffolds. All of these material have been found to support the growth of LEST cells in vivo, but only human amniotic membrane and fibrin gels have been investigated in clinical studies with positive outcomes (Fig. 18.2).

Cultured oral mucosa stem cell transplant (COMET): It is closely related to LSCT. It has also been used for LSCD treatment. Cultured oral mucosal epithelial transplantation (COMET) has several potential advantages. There are no risk of immune-mediated rejection, and, in the absence of autoimmune disease, immunosuppression is not required. Published outcomes for COMET show that a stable corneal surface is achieved in up to 100 % of eyes at 1 year, 100 % at 14 months, 67 % at 20 months, and 92 % at 4 years. Visual acuity was better than pretreatment levels in 90 % of eyes at 1 year, 100 % at 14 months, and 67 % at 20 months, and 53 % remained improved for 4 years following surgery (Figs. 18.5 and 18.6).