Published in the Journal of Clinical Ophthalmology, 2009, Issue 2 Feng Xianyu Tao Liming ————————– Author Affiliations: Ophthalmology Department, Lujiang County People’s Hospital, Chaohu, 231500, China; Ophthalmology Department, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China; Corresponding Author: Tao Liming Email: lmtao9@ 163.com [Abstract] Objective To study the effect of single-dose mitomycin C (MMC) local injection on blood vessels and fibroblasts in pterygium tissues, and to explore the mechanism of the therapeutic effect of MMC on pterygium. Methods Pterygium was randomly divided into two groups according to the order of consultation: group A directly excised the pterygium tissue and left the specimens for pathological examination; group B was injected into the neck of pterygium, and MMC was injected locally into the pterygium tissue once, 0.1 ml/times (0.4 mg/ml), and pterygium was surgically excised from 3 to 10 weeks after the injection of the drug, and the specimen was left behind. group N was the normal bulboconjunctivae of those who had suffered from other ophthalmopathies. HE staining was done for each specimen to observe the changes of blood vessels and fibroblasts in the tissue. Results Under light microscope, the pterygium head and body in group B showed reduced blood vessels and atrophy of small blood vessels near the basement membrane. Fibroblasts were reduced, with small cytosol, deeply stained nuclei, irregular nuclear morphology, and poorly defined cytoplasm.The number of blood vessels in the specimens of groups A and B was significantly higher than that of normal conjunctiva, with scattered distribution.The number of blood vessels and fibroblasts in the head and body of group A was significantly different from that of groups B and N respectively (P