A negative correlation of axial length with aqueous humor concentration of cytokines in patients with congenital cataracts

PURPOSE: To investigate the association between cytokine (and related proteins) concentrations in the aqueous humor (AH) of patients with congenital cataracts and preoperative and postoperative axial length. METHODS: Samples from the AH were collected from 25 eyes of 17 patients with congenital cataracts who underwent congenital cataract extraction and intraocular lens implantation. Multiplex enzyme-linked immunosorbent assays (ELISAs) and Luminex xMAP technology were used to assess the concentration of cytokines or chemokines, and acute phase proteins in the AH. Axial lengths were measured before surgery and at 3 months, 6 months, and 1 year after surgery. RESULTS: The mean protein concentrations were determined in the AH of patients with congenital cataracts. The following proteins were assessed: VEGF (9.89 ± 4.94 pg/ml), TNF-α (1.88 ± 0.12 pg/ml), TGF-β2 (1622.88 ± 762.53 pg/ml), IL-1RA (110.78 ± 141.29 pg/ml), IL-1β (1.85 ± 0.13 pg/ml), IL-2 (41.96 ± 14.48 pg/ml), IL-4 (9.75 ± 1.32 pg/ml), IL-5 (1.38 ± 0.09 pg/ml), IL-6 (2.31 ± 5.97 pg/ml), IL-10 (1.46 ± 0.47 pg/ml), IL-12p70 (21.50 ± 1.60 pg/ml), IL-15 (2.23 ± 0.18 pg/ml), IL-17A (1.22 ± 0.11 pg/ml), GM-CSF (2.80 ± 0.38 pg/ml), IFN-γ (9.20 ± 0.42 pg/ml), CCL2/MCP-1 (131.45 ± 90.45 pg/ml), CCL3/MIP-1α (87.14±3.83 pg/ml), CCL4/MIP-1β (66.26 ± 2.22 pg/ml), CXCL10/IP-10 (13.99 ± 39.66 pg/ml), CCL11/eotaxin (27.17 ± 2.00 pg/ml), and PDGF-BB (0.43 ± 0.04 pg/ml). These data suggested a negative correlation between the level of VEGF in the AH and the preoperative axial length (r(2) = 0.2615, p<0.01). Similarly, the level of GM-CSF and CCL11/eotaxin in the AH decreased with an increase in axial length (r(2) = 0.2456, p = 0.01; r(2) = 0.1758, p=0.037). At 1 year post-surgery, a negative correlation was observed between the level of PDGF-BB and the change in the axial length (r(2) = 0.2133, p = 0.02). Axial elongation at 1 year post-surgery was 0.24 ± 0.34 mm. The predicted change in axial length at 1 year post-surgery was 1.05 ± 0.83 mm, and the actual axial elongation was statistically significantly smaller than the predicted change in healthy children (paired t test, p<0.01). CONCLUSIONS: Increased preoperative axial lengths were negatively correlated with AH levels of VEGF, GM-CSF, and CCL11/eotaxin. The level of PDGF-BB was negatively correlated with the change in axial length 1 year post-surgery. These data suggest that the concentrations of these proteins in the AH may have predictive value for changes in axial length in patients with congenital cataracts, and possibly provide a useful prognostic modality.