A Comparison of Scleral Tunnel and Pericardial Graft Implantation Techniques in Patients undergoing Ahmed Glaucoma Valve Implantation
Authors: Bakr Medhat A , Al-Eid Shaikha 
Published: December 2020

The purpose of this study was to compare the two methods autologous scleral flap (scleral tunnel) and pericardial patch graft of tube covered in Ahmed glaucoma valve (AGV) in refractory glaucoma with respect to the tube exposure, infection, level of Intraocular Pressure (IOP), and any other complications due to applications of each technique. A retrospective chart review of 113 eyes in 102 patients with refractory glaucoma who underwent ahmed glaucoma valve (AGV) implantation (39 eyes in scleral tunnel and scleral flap group &ldquo;first group&rdquo; and 74 eyes in pericardium graft group&rdquo; second group&rdquo;) was performed. The procedures in these eyes were performed between January 2007 and October 2015 in a tertiary eye care hospital in KSA. The mean age was 56 &plusmn; 19 (8 months- 83 years) in the Scleral tunnel group and 50 &plusmn; 27 (1- 78 years) in the Pericardium group (p = 0.023). Fifty-six males and 57 females were included in the study. Medians of the follow-up were 48 &plusmn; 25.5 months (3 &ndash; 89) for the Scleral tunnel group and 29 &plusmn; 21.4 months (2 &ndash; 92) for the Pericardium group, and it is statistically significant (P &lt; 0.001). According to the findings, preoperative diagnosis in the two groups included neovascular glaucoma (NVG) found in 21 eyes (53.8%) in the Scleral tunnel group versus 18 eyes (24.3%) in the Pericardium group (p = 0.009). Exposure of the valve was found in 15 eyes (20.27%) in Pericardium graft group versus 2 eyes (5.12%) only in scleral tunnel group (p = 0.002). These exposed valves lead to endophthalmitis in 5 cases in the second group and no single case in scleral tunnel group was detected (P &lt; 0.001). The postoperative IOP values were statistically insignificant in all different time periods.

Scleral tunnel method has less exposure rate than the pericardium graft.

The purpose of this study was to compare the two methods autologous scleral flap (scleral tunnel) and pericardial patch graft of tube covered in Ahmed glaucoma valve (AGV) in refractory glaucoma with respect to the tube exposure, infection, level of Intraocular Pressure (IOP), and any other complications due to applications of each technique. A retrospective chart review of 113 eyes in 102 patients with refractory glaucoma who underwent ahmed glaucoma valve (AGV) implantation (39 eyes in scleral tunnel and scleral flap group &ldquo;first group&rdquo; and 74 eyes in pericardium graft group&rdquo; second group&rdquo;) was performed. The procedures in these eyes were performed between January 2007 and October 2015 in a tertiary eye care hospital in KSA. The mean age was 56 &plusmn; 19 (8 months- 83 years) in the Scleral tunnel group and 50 &plusmn; 27 (1- 78 years) in the Pericardium group (p = 0.023). Fifty-six males and 57 females were included in the study. Medians of the follow-up were 48 &plusmn; 25.5 months (3 &ndash; 89) for the Scleral tunnel group and 29 &plusmn; 21.4 months (2 &ndash; 92) for the Pericardium group, and it is statistically significant (P &lt; 0.001). According to the findings, preoperative diagnosis in the two groups included neovascular glaucoma (NVG) found in 21 eyes (53.8%) in the Scleral tunnel group versus 18 eyes (24.3%) in the Pericardium group (p = 0.009). Exposure of the valve was found in 15 eyes (20.27%) in Pericardium graft group versus 2 eyes (5.12%) only in scleral tunnel group (p = 0.002). These exposed valves lead to endophthalmitis in 5 cases in the second group and no single case in scleral tunnel group was detected (P &lt; 0.001). The postoperative IOP values were statistically insignificant in all different time periods.

Scleral tunnel method has less exposure rate than the pericardium graft.