The effects of glaucoma filtering surgery on anterior chamber-associated immune deviation and contribution of lymphatic drainage in rats

Abstract

To investigate whether glaucoma filtering surgery (GFS) in rats would impair the eye's capacity to induce anterior chamber-associated immune deviation (ACAID) and assess the possible mechanism involved. Rats subjected to GFS were injected with bovine serum antigen (BSA) into the anterior chamber to induce ACAID. Animals that had their cervical lymph nodes (CLNs) excised before filtering surgery and those that had sham filtering surgery served as control comparison groups. Antigen-specific delayed-type hypersensitivity (DTH) was used to identify the induction of ACAID. Antigen level in the CLNs was indicated by the percentage of FITC-positive cells in CLNs after FITC dextran was injected into the anterior chamber. Statistical analyses were performed using the student's t-test for comparison of data between control and experimental groups. A P<0.05 was required for results to be considered statistically significant. Rats undergoing GFS demonstrated antigen-specific DTH, while those in the sham filtering surgery or CLNs excised groups failed to acquire an antigen-specific DTH response. The percentage of FITC-positive cells in CLNs was significantly increased (P=0.001) in GFS (mean+/-SD: 2.96+/-0.67%) vs controls (1.57+/-0.48%) at 1 day, but not at 3, 5, 7, or 12 days post-antigen injection. GFS prevents the induction of ACAID in rats, and the antigen drainage to CLNs plays a critical role in this process. The results suggest that the ocular immune status might be altered by GFS.