Effect of Postoperative Trimming of the Tube Portion of Ahmed Glaucoma Valve on Corneal Endothelial Cell Loss.

PRCIS

We reduced the tube length through a small limbal incision in eyes that underwent Ahmed glaucoma valve (AGV) implantation and found that the rate of corneal endothelial cell (CEC) density was markedly reduced from -12.2% per year to -3.5% per year after this simple procedure.

PURPOSE

The aim was to evaluate the effect of postoperative tube tip trimming (TT) after AGV implantation on CEC loss.

METHODS

In this retrospective cohort study, a total of 75 eyes from 67 patients (41 eyes in the AGV implantation only group (AGVG: mean follow-up, 42.2±13.8 mo) and 34 eyes in the TT after AGV implantation group (TAGVG: mean follow-up, 64.9±18.5 mo) were analyzed. TT was performed through a small limbal incision at a mean of 41 months after AGV implantation. Both groups were followed up for at least 1 year and underwent at least 2 specular microscopic examinations after AGV implantation and/or TT.

RESULTS

In the AGVG, CEC density was reduced from 2247.0±527.3 to 1665.7±643.3 cells/mm2 (P<0.001). In the TAGVG, it was reduced from 2383.1±619.4 to 1552.9±700.9 cells/mm2 before TT (mean 41 mo of follow-up) and after TT, to 1394.6±654.7 cells/mm2 (mean 26 mo of the follow-up). The reduction rate of CEC density before TT was -12.2±6.5% per year, and this rate was significantly reduced to -3.5±6.9% per year after TT in the TAGVG (P=0.002). The probability of corneal failure defined as a 15% reduction in CEC density was significantly reduced after TT in TAGVG (P=0.038).

CONCLUSIONS

Tube TT after AGV implantation markedly reduced the rate of CEC loss without serious complications in eyes with AGV implantation.