Elevated tissue transglutaminase levels in aqueous humor of congenital cataractous eyes with long axial length

OBJECTIVE: To investigate the distribution of axial length (AL) and posterior staphyloma (PS) in congenital cataract (CC) patients. The correlation between AL and the concentration of tissue transglutaminase (TGM2) in the aqueous humor (AH) of cataractous eyes was also evaluated. METHODS: Cross-sectional data were collected from 499 children with CC who underwent phacoemulsification, anterior vitrectomy, and IOL implantation. AL measured by IOLMaster or A-scan ultrasonography and the presence of PS examined by B-scan ultrasonography were recorded. TGM2 levels in AH of 15 CC patients with normal axial length (NAL) and 15 CC patients with PS or long axial length (LAL) were measured by enzyme-linked immunosorbent assay. RESULTS: The presence of PS in congenital cataractous eyes was 11.02%, and the presence of PS + LAL in congenital cataractous eyes was 29.06%. The AH levels of TGM2 in the cataractous group with NAL were lower than those in the cataractous group with PS or LAL (P < 0.001). The concentration of TGM2 in AH were positively correlated with AL of the patients’ eyes (P = 0.001). Additionally, we found that TGM2 expressed in the cytoplasm of lens epithelial cells of cataractous eyes, and the expression level increased with the AL value. CONCLUSIONS: This study begins to lay the groundwork for investigating the characteristics of PS and LAL in patients with CC. Furthermore, AL was positively correlated with AH levels of TGM2.