Lymphatic Vessels Correlate Closely with Inflammation Index in Alkali Burned Cornea

Abstract

Purpose: To study the relationship between corneal lymphangiogenesis and inflammation in alkali burned corneas.

Methods: Rat corneal lymphatic and blood vessels were labeled and distinguished by whole mount immunofluorescence and 5'-nase-alkaline phosphatase (5'-NA-ALP) double enzyme-histochemistry. Then, lymphatic vessel areas (LVA) and lymphatic vessel counting (LVC) were examined. Corneal inflammation was evaluated by inflammation index (IF) grading, histopathology, electron microscope, and polymorphonuclear leukocyte (PMN) infiltration. The relationship between LVC, LVA, IF, and PMN was examined, respectively. In addition, corneal lymphatic vessels of eleven human alkali burned corneas were examined by lymphatic vessel endothelial receptor (LYVE-1) immunohistochemistry.

Results: Corneal lymphangiogenesis occurred on Day 3, reached the peak at the end of two weeks, and disappeared five weeks after alkaline burns. Both LVA and LVC were strongly and positively correlated with IF after corneal alkaline burns. However, the relationship between LVC and PMN, between LVA and PMN were significant but converse. Among eleven human alkali burned corneas, corneal lymphangiogenesis was present in three corneas.

Conclusions: Corneal lymphagiogenesis develops after alkaline burns and correlates closely with corneal inflammation.

KEYWORDS::

• Alkaline burns
• Cornea
• Inflammation
• Lymphangiogenesis

ACKNOWLEDGMENTS

The study was supported by China National Natural Science Fund (30700927); Guangdong Natural Science Foundation (06300677); China Postdoctoral Foundation (20050384); and Guangdong technology project (93068).

We acknowledge Dr. L. Caoyang, Dr. X. Chuangcao, and Dr. Z. Wei for their invaluable technical support and we thank teacher Maureen A. Power for the revision.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.