Short-term endothelial cell density changes after gonioscopy-assisted transluminal trabeculotomy

Abstract

Purpose: To investigate the reduction in corneal endothelial cell density associated with gonioscopy-assisted transluminal trabeculotomy (GATT) in a short-term follow-up period. Methods: A retrospective analysis of the medical charts of patients with open-angle glaucoma who underwent gonioscopy-assisted transluminal trabeculotomy isolated or combined with phacoemulsification (phaco-gonioscopy-assisted transluminal trabeculotomy) was conducted. Patients who underwent phacoemulsification alone were included as controls. The endothelial cell density data (assessed using a specular microscope) before and at the first month after operation were collected and then compared. Results: Sixty-two eyes previously treated with gonioscopy-assisted transluminal trabeculotomy (gonioscopy-assisted transluminal trabeculotomy, n=39 eyes; phaco-gonioscopy-assisted transluminal trabeculotomy, n=23 eyes) fulfilled the inclusion criteria. The mean age of the study patients was 61.3 ± 18.4 years in the stand-alone gonioscopy-assisted transluminal trabeculotomy group and 60.4 ± 11.9 in phaco-gonioscopy-assisted transluminal trabeculotomy group. Men comprised 66.6% of the patients in the isolated gonioscopy-assisted transluminal trabeculotomy group and 56.5% of those in the phaco-gonioscopy-assisted transluminal trabeculotomy group. The mean visual field defects (mean deviation index) were -13.9 ± 9.2 and -10.3 ± 7.7 dB in the isolated gonioscopy-assisted and phaco-gonioscopy-assisted transluminal trabeculotomy groups, respectively. The patients in the former group presented a mean endothelial cell density reduction of 28.8 cells/mm² (1.31%; p=0.467). In the latter group, the mean endothelial cell density loss was 89.4 cells/mm² (4.36%; p=0.028). The control eyes (23 patients) presented a mean endothelial cell density change of 114.1 ± 159.8 cells/mm² (4.41%; p=0.505). The endothelial cell density reduction in the phaco-gonioscopy-assisted transluminal trabeculotomy group was not significantly different from that in the controls (p=0.81). Conclusions: Gonioscopy-assisted transluminal trabeculotomy appears to be a safe procedure for the corneal endothelial cell layer when performed either isolated or combined with cataract extraction in a short-term follow-up period.