Ciliary sulcus tube implantation preferred over anterior segment placement in pseudophakic patients

Ciliary sulcus tube implantation appears to be a better surgery approach than anterior segment placement in reducing endothelial cell loss in pseudophakic patients, suggests a study.

The investigators compared the effects of the Ahmed glaucoma valve (AGV) with sulcus versus anterior chamber (AC) tube placement on the corneal endothelial density and morphology over time in this nonrandomized, interventional study. One hundred six eyes from 101 pseudophakic patients who had the AGV tube placed in the AC (acAGV) and 105 eyes from 94 pseudophakic patients who had the AGV tube placed in the ciliary sulcus (sAGV) were included.

Participants underwent preoperative specular microscopy, which was repeated postoperatively in 2019. Anterior segment optical coherence tomography was conducted for patients who underwent sAGV to assess the sulcus tube position. The investigators then conducted gonioscopy to document peripheral anterior synechiae (PAS). They used linear mixed-effects models to compare the different ocular and endothelial measurements between groups and to identify risk factors for endothelial cell density (ECD) loss over time.

Baseline characteristics were similar between the acAGV and sAGV groups, except that the former had longer follow-up (37.6 vs 20.1 months; p<0.001). Mean monthly loss in central ECD was significantly greater in the acAGV group than in the sAGV group (29.3±29.7 vs 15.3±20.7 cells/mm²; p<0.0001). Both groups showed comparable mean monthly change in coefficient of variation (p=0.28).

In multivariate analyses, younger age (p=0.02) and tube location (p<0.0001) in the AC correlated with faster central ECD loss. PAS also correlated with faster central ECD loss in patients with sAGV (p=0.002), but a more forward tube position tenting the iris did not (p>0.05).