The surgical treatment of pterygium has a long history, from the original simple excision to the current widespread use of corneal limbal stem cell transplantation, and many effective surgical approaches have emerged through continuous exploration and improvement. 3. 1. The earliest surgical treatment of pterygium was based on simple excision of the pterygium. These methods are simple, easy to perform, and easily used by primary care hospitals, and include the following. 3. 1. 1 The scleral exposure approach removes the pterygium, completely removing the subconjunctival tissue from the lesion and exposing a small area of the sclera near the affected cornea. 3. 1. 2 The pterygium transfer method separates the head of the pterygium from the sclera and transfers it to the upper or lower bulbar conjunctiva. These methods are not perfect, and the main problem is that the recurrence rate of pterygium after surgery is often 30% to 50%, or even up to 60%. These methods have been improved in order to reduce the recurrence rate of pterygium after surgery. With the advent of medical equipment and technology, the use of the surgical microscope in the treatment of pterygium has led to the emergence of more difficult but effective surgical procedures. 3. 2 Modified procedures 3. 2. 1 Transfer of the tipped conjunctival flap Mechanism of action: The transplanted conjunctival flap and the scleral exposure near the corneal limbus act as a barrier to prevent the growth of pterygium tissue into the cornea. Procedure: Excision of the pterygium and its underlying diseased tissue, and replacement grafting of healthy conjunctiva from the upper and lower fornix to cover the defective area according to the condition of the excised conjunctival defect. In this procedure, the diseased tissue is removed as much as possible, and the relatively healthy conjunctival tissue is preserved, and the conjunctival flap is not taken too thickly. ( 1) The tipped conjunctival flap is a healthy conjunctiva with blood supply, which can be rapidly activated after transfer and can effectively prevent the recurrence of pterygium through the barrier effect, whereas the amniotic membrane and free conjunctival flap only play a similar role as the basement membrane, and eventually the subhealthy conjunctival epithelium around the pterygium grows into the scleral bare area; ( 2) The postoperative color change is slight, avoiding the impact of scar shrinkage on the appearance; ( 3) The tipped conjunctival flap is easier to operate than the free conjunctival flap; ( 3) The tipped conjunctival flap is easier to operate than the free conjunctival flap. ( 4) The blood vessels on the tipped conjunctival flap change from perpendicular to the angular scleral margin to parallel to the angular scleral margin after 90% transposition, which helps to prevent the recurrence of pterygium. 3. 2. 2 Amniotic membrane transplantation Since 1995, when Kmi and Tseng reported successful reconstruction of the ocular surface with treated preserved amniotic membrane, amniotic membrane transplantation has been widely used in the treatment of pterygium. Mechanism of action: Amniotic membrane is the thickest basement membrane in the body, which promotes epithelial healing, maintains a normal epithelial phenotype, reduces inflammation and vascularization, and contains various protease inhibitors in its matrix that inhibit pterygium fibroblast differentiation, promote the proliferation and differentiation of corneal limbal stem cells, promote the migration and proliferation of peripheral conjunctival epithelial cells to the amniotic membrane, and facilitate the growth and migration of corneal epithelial cells and prevent their apoptosis, It has various functions such as anti-fibrosis and anti-new blood vessel formation. Results: The recurrence rate of pterygium treated with amniotic membrane transplantation varies from 3. 8% to 10. 9% for primary pterygium to 25% to 37. 5% for recurrent pterygium, depending on the nature of the pterygium, the age and race of the subject, and the surgical technique. Advantages: Wide variety of sources. There is no limit to the size of the material. Amniotic membrane grafting is a promising method for large pterygium with large surgical incisions, limited conjunctival extraction, or when conditions make it impossible to continue. In addition, it is an ideal surgical procedure for those who need surgery for glaucoma. 3. 2. 3 Corneal Margin Stem Cell Transplantation Corneal Margin Stem Cell Transplantation started in the 1970s and was actually developed on the basis of T hoft’s conjunctival transplantation and corneal epithelial transplantation. With the understanding of the theory of corneal limbal stem cells, the transplantation of corneal limbal stem cells has been widely used in clinical practice until recently. They are the source of corneal epithelial regeneration and the fence and barrier between the conjunctiva and the cornea, preventing neovascularization and pseudopterygium from invading the cornea under normal physiological conditions. Under normal physiological conditions, it prevents neovascularization and pseudopterygium from invading the cornea. Based on these mechanisms, providing a healthy source of stem cells for the damaged corneal rim is the key to successful surgery. The use of autologous corneal margin stem cell transplantation to treat pterygium can restore the epithelial tissue of the corneal margin, restore the number and function of stem cells, restore corneal transparency, and prevent the conjunctival epithelium and neovascularization from invading the cornea, thus achieving the goal of treating pterygium and preventing its recurrence.