Limbal conjunctival autografting involves transplantation of limbal stem cells in addition to autologous conjunctiva in order to cover the defect created from excision of the pterygium. The benefit of this method is that, in addition to decreasing recurrence rates, the limbal stem cells promote healing.14 Sutured limbal conjunctival autografts have a recurrence rate ranging from 0% to 14.29%.14 The use of fibrin glue was shown in one study to significantly decrease the rate of recurrence.19
A conjunctival flap requires undermining of the conjunctiva at the donor site without detaching the tissue from its origin. The surgeon then rotates the flap to cover the defect left by excision of the pterygium. Few complications have been reported for this procedure, apart from conjunctival cyst formation and flap retraction.13 Alpay et al13 found a recurrence rate of 33.33% with this technique and noted poor cosmesis, which improves with time.
An amniotic membrane (AM) graft can also be used to cover bare sclera following pterygium excision (Figure 2). These grafts are thought to promote healing and reduce rates of recurrence because of their anti-inflammatory properties, their promotion of epithelial growth, and their suppression of transforming growth factor β (TGF-β) signaling and fibroblast proliferation.14 Recurrence rates of pterygia following amniotic membrane grafting (AMG) are cited between 14.5% and 27.3%.14 The use of postoperative steroid injections following AMG also reduces the rate of recurrence.14 When compared to conjunctival and limbal autografting, recurrence rates are higher for AMG.20 AMG shows particular promise over the other grafting procedures in certain circumstances, such as when preexisting conjunctival scarring precludes the harvesting of donor conjunctiva for an autograft. AMG is also helpful when the superior conjunctiva must be spared for future glaucoma filtering surgery, as well as in cases of large or double-headed pterygia.