The long‐term postoperative effect of the Baerveldt glaucoma drainage device and of a trabeculectomy on the corneal endothelium

Abstract

Purpose: To determine whether the postoperative corneal endothelial cell density (ECD) differs between glaucoma patients who underwent Baerveldt implant (BGI) surgery and patients who underwent a trabeculectomy (TE) over 5 years ago. Methods: Cross-sectional, observational study including 34 patients who underwent TE and 36 patients who underwent BGI surgery 5-11 years ago, as part of a randomized clinical trial. None of the patients had a history of intraocular surgery prior to their glaucoma surgery. Central and peripheral ECD was measured by using a non-contact specular microscope. Results: Central and peripheral ECD in the TE group was 2285 AE 371 cells/ mm 2 (mean AE SD) and 2463 AE 476 cells/mm 2 , respectively. Central and peripheral ECD in the BGI group was 1813 AE 745 cells/mm 2 and 1876 AE 764 cells/mm 2 , respectively. The central and peripheral ECD was statistically significantly higher in the TE group than in the BGI group (p = 0.001 for both). Additional intraocular surgical interventions were more prevalent in the BGI group (23) than in the TE group (5) (p < 0.001). In a subanalysis, without eyes that had undergone additional surgical interventions, only the peripheral ECD was statistically significantly higher in the TE group compared with the BGI group (p = 0.011). For the BGI group, a longer postoperative period resulted in a lower central ECD (r = À0.614, p = 0.004). Conclusion: Long-term ECD in eyes that underwent a BGI was considerably lower compared with eyes that underwent a TE, mainly in the peripheral cornea. This suggests that BGI causes a larger decrease of ECD than TE. Additionally, the decrease after BGI appears to continue for a longer period than after TE.

The surgical management of glaucoma: A review

“…121 There is significantly more loss of ECD with AC tubes than trabeculectomies. 122 The TVT, ABC and AVB all reported 5-year rates of corneal endothelial surgery between 2.1% and 8.4%. 123 Persistent corneal oedema occurred in 16% at 5 years in the TVT study.…”

Changes in corneal endothelial cell density after trabeculectomy

“…6 As with any surgery involving the anterior segment, trabeculectomy has the potential to cause corneal injury and is associated with an accelerated decline in corneal endothelial cell density (CECD). [7][8][9] In current literature, several studies have described significant changes in CECD after trabeculectomy. 4,5,9 However, there are limited data on risk factors for corneal endothelial cell loss and the mechanisms responsible for these changes are not well understood.…”

“… 6 As with any surgery involving the anterior segment, trabeculectomy has the potential to cause corneal injury and is associated with an accelerated decline in corneal endothelial cell density (CECD). 7 – 9 …”

“…Post-operative 5-FU injections [mean ± SD (range)]3.53 ± 2.23(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11) Abbreviations: SD, standard deviation; CECD, corneal endothelial cell density; ACD, anterior chamber depth; CCT, central corneal thickness; AL, axial length; IOP, intraocular pressure; 5-FU, 5-fluorouracil.…”