AIM: To examine the relations between lymphangiogenesis and the size of pterygium. METHODS: Tissues from 88 primary and 34 recurrent pterygia were evaluated, and those from 7 nasal epibulbar conjunctiva segments were used as controls. Pterygium slices from each patient were stained with LYVE-1 monodonal antibodies to identify lymphatic microvessel for calculating lymph-vascular area (LVA), lymph-microvascular density (LMD) and lymph-vascular luminal diameter (LVL). Also, the relations between lymphangiogenesis (measuring by LVA, LMD and LVL) and the size of pterygium (extension, width and area) were explored. RESULTS: There were a few LYVE-1 ((+)) lymphatic vessels in normal epibulbar conjunctiva segments. However, the number of lymphatic vessels slightly increased in primary pterygia and dramatically increased in recurrent pterygia. LVA, LMD and LVL significantly increased in recurrent pterygia in comparison with primary pterygia (all P<0.05). Both LMD and LVA were correlated with the width and area of pterygia (both P<0.05), and LVA was also correlated with the extension of pterygia(P<0.05). CONCLUSION: Lymphangiogenesis is correlated with the size of pterygium. The outgrowth of lymphatic vessels might contribute to the development of pterygia.
AIM: To examine the relationship between angiogenesis and lymphangigenesis in recurrent pterygia. METHODS: Tissues from 34 excised recurrent pterygia (including 12 Grade 1, 10 Grade 2, and 12 Grade 3) were involved in the study and tissues from 7 nasal epibulbar conjunctivae segments were used as controls. Sections from each pterygium were immunostained with CD31 and LYVE-1 monoclonal antibodies to evaluate lymphatic microvessel density (LMVD) and blood microvessel density (BMVD), and the relationship between LMVD and BMVD in the pterygium was examined. RESULTS: There was a large number of CD31(+) LYVE-1((-)) blood vessels but only a few CD31 (+)LYVE-1 ((+)) lymphatic vessels in grades 1 and 2 pterygium. However, lymphatic vessels were dramatically increased in grade 3 pterygium. LMVD correlated dosely with BMVD in all pterygia, including grades 1, 2 and 3 peterygium patients (all P values < 0.01). Although both the density of blood and lymphatic vessels increased in recurrent pterygia, lymphatic vessels developed much faster than blood vessels, especially in grade 3 pterygia. CONCLUSION: There is a significant but not parallel relationship between angiogenesis and lymphangiogenesis in recurrent pterygium. The outgrowth of blood and lymphatic vessels provide evidence that immunological mechanism may play a role in the development and recurrence of pterygium.
