Abstract
Purpose :
To assess the effect of different tube locations on the density and morphology of corneal endothelial cells after Ahmed glaucoma valve (AGV) implantation.
Methods :
Spectral microscopy was performed for 3 groups of subjects: (1) 106 eyes from 101 patients who underwent AGV implantation with tube placed in the anterior chamber (acAGV); (2) 105 eyes from 94 patients with AGV tube in the sulcus (sAGV); (3) 53 control eyes from 33 patients who had phacoemulsification only. In addition to obtaining patient demographic and glaucoma history, endothelial cell density (ECD) and coefficient of variation (CV) were measured in 3 corneal locations including central, superotemporal (ST) and inferonasal (IN) quadrants. Monthly changes in the measurements were calculated by dividing ECD and CV by the time elapsed since surgery in order to adjust for the difference in follow-up times. ANOVA was used to compare the measurements among the three groups. Linear mixed model was used to identify risk factors for ECD loss.
Results :
The mean intraocular pressure showed no differerence between acAGV and sAGV groups (P=0.621). The mean age of the control group was 71.64±9.57 years, older than the acAGV (64.77±15.08 years) and the sAGV groups (66.64±15.46 years) (P=0.018). The mean time since acAGV surgery was 37.58±20.14 months, significantly longer than the sAGV group (20.11±17.2 months) and the control group (25.86±20.47 months) (P<0.001). The mean monthly decrease in central ECD was 29.27±29.72 in the acAGVgroup, significantly higher than the sAGV (15.25±20.74, P<0.001) and the control groups (16.3±17.56, P=0.024). There was no significant difference between the sAGV and the control groups (P>0.05). These trends were similar in ST and IN quadrants. The mean monthly changes in CV were not different among the 3 groups (sAGV:0.36±1.63, acAGV:0.08±0.58, control:0.15±0.35, P=0.135). In the sAGV group, whether the tube was lifting up the iris made no difference on ECD compared to control (P>0.05). Multiple mixed linear regression analysis showed that age and tube location were associated with postoperative ECD in central, ST and IN cornea.
Conclusions :
Endothelial cell damage after AGV implantation was lower when the tube is placed in the sulcus compared to the anterior chamber. Sulcus tube implantation may be a preferred technique to prevent endothelial cell loss while maintaining IOP control.
This is a 2020 ARVO Annual Meeting abstract.