Clinically, patients with pterygium treated by temporary amniotic membrane patch after pterygium removal were found to have circulating CD34+ cells, which represent the active subset of fibrocytes, increased slightly compared with a marked increase in the bare sclera group; this might represent an effective therapeutic approach for controlling pain—lower collagen expression, and excessive infiltration of bone marrow-derived stem cells [60]. This evidence concerns the gene CD34 and pterygium.