Abstract
PURPOSE: To investigate central and peripheral corneal endothelial cell density (ECD) in relation to Baerveldt (BV) glaucoma drainage device (GDD) tube corneal (TC) distance. METHODS: Prospective study of all patients scheduled for glaucoma tube surgery with 36 months follow-up. A BV GDD was inserted into the anterior chamber (AC). Anterior segment optical coherence tomography (AS-OCT) scans were made to determine the TC distance. Central and peripheral ECD was measured, preoperatively and at 3, 6, 12, 24 and 36 months postoperatively. RESULTS: Fifty-three eyes were included [primary open-angle glaucoma, (n = 13); secondary glaucoma, (n = 30); and primary angle-closure glaucoma, (n = 10)]. Central ECD significantly decreased during follow-up, with a mean decrease of 4.54% per year (p < 0.001), and 6.57% in the peripheral quadrant closest to the BV GDD tube (PQC, p < 0.001). In the PQC, a yearly decrease of 1.57% was shown after transiridial tube placement versus 7.43% after placement 'free' into the AC (p = 0.006). Endothelial cell (EC) loss was related to TC distance (mean 1.69 mm), with a central loss of 6.20% and 7.25% in the PQC per year with shorter TC distances, versus a central loss of 4.11% and 5.77% in the PQC per year with longer TC distances (outside mean ± 2SD, p < 0.001). A difference in EC loss by glaucoma subtype was not identified. CONCLUSION: The TC distance is of significant influence on corneal ECD, a shorter TC distance causing more severe EC loss, especially in the PQC. Transiridial placement of the BV GDD tube seems safer than placement 'free' into the AC.