Purpose To compare the effects of guided and non-guided Ahmed glaucoma valve (AGV) implantation on the corneal endothelium. Methods Medical records of patients who underwent AGV implantation in the anterior chamber (AC) were reviewed retrospectively. The eyes were divided into two groups depending on the use of a guidance technique with spatula and a 4–0 nylon intraluminal stent. Specular microscopy was performed to measure corneal endothelial cell density (ECD) loss after surgery, and the rate of ECD change was calculated. Tube parameters were measured using anterior segment optical coherence tomography (AS-OCT). Results The ECD loss during 2 years of follow-up was significantly lower in the guided AGV implantation (gAGV) group than in the non-guided implantation (ngAGV) group, and the rate of ECD change was -0.62 ± 1.23 and -1.42 ± 1.57%/month in the gAGV and ngAGV groups, respectively (p = 0.003). The mean tube–cornea distance (TCD) and mean tube–cornea angle (TCA) were significantly greater in the gAGV group than in the ngAGV group. The frequency of tube repositioning within 2 years after surgery was 0% in the gAGV group and 12.66% in the ngAGV group (p = 0.005). Conclusions The use of a guidance technique can reduce corneal endothelial loss during the first 2 years after AGV implantation in the AC. The tube was positioned at a more distant and wider angle from the cornea in the eyes of the gAGV group, which may have contributed to the reduced need for tube repositioning to prevent corneal decompensation.

To compare the properties of the lamina cribrosa (LC) and the peripapillary vessel density between branch retinal vein occlusion (BRVO) and normal-tension glaucoma (NTG), using swept-source optical coherence tomography and optical coherence tomography angiography. Methods This retrospective study included 21 eyes of 21 patients with BRVO and 43 eyes of 43 patients with NTG who were treated from June 2016 to September 2017. The anterior LC depth (ALCD) and LC thickness (LCT) at the mid-superior, central, and mid-inferior levels; the mean difference in ALCD; and the peripapillary vessel density in the superficial and deep capillary plexuses and the choriocapillaris were compared between groups. Results ALCD at the mid-superior, central, and mid-inferior levels was significantly greater in the NTG group (P < 0.05), while LCT was comparable between the groups. The mean difference in ALCD was significantly greater in the BRVO group (P = 0.03). The peripapillary vessel density in the superotemporal segment of the superficial capillary plexus was significantly lower in the BRVO group, while the density in all segments of the choriocapillaris was significantly lower in the NTG group (P < 0.05 for all). Conclusions Our findings demonstrate that BRVO and NTG have different LC structures and peripapillary vessel densities.

Purpose To compare quantitative visual tests, such as visual acuity, contrast sensitivity, and color vision tests in patients with primary open-angle glaucoma (POAG) patients according to three different light systems with different color-rendering index (CRI). Methods This was a cross-sectional study of 36 eyes in 36 patients with POAG. Three different light systems consisting of a 3-band fluorescent lamp (CRI 80), a white LED (CRI 75), and a quantum dot LED (CRI > 95) were used. All lights had the same illuminance of 230 lx to exclude illuminance effects. The visual testing included best-corrected visual acuity (BCVA) using an ETDRS chart, a CSV-1000E contrast test, and a color test performed by the Farnsworth Munsell 100-hue test. Results There was no significant difference in BCVA (p = 0.86). There were no significant differences in the detail contrast tests according to the three light systems (p = 0.95, p = 0.94, p = 0.94, respectively, p = 0.64). There was significant difference between the three light systems in color test (p = 0.042). The color test scores with a quantum dot LED were significantly lower than those of the white LED and 3-band fluorescent lamp (p = 0.03 and 0.047, respectively). Conclusions POAG patients did not show significant differences in visual acuity scores and contrast test scores, expressed as black and white symbols, according to the different light systems. However, POAG patients tested under a quantum dot LED (CRI > 95) could distinguish color differences better than in the other light systems.

Purpose: To compare the effects of guided and non-guided Ahmed glaucoma valve (AGV) implantation on the corneal endothelium.Methods: Medical records of patients who underwent AGV implantation in the anterior chamber (AC) were reviewed retrospectively. The eyes were divided into two groups depending on the use of a guidance technique with spatula and a 4-0 nylon intraluminal stent. Specular microscopy was performed to measure corneal endothelial cell density (ECD) loss after surgery, and the rate of ECD change was calculated. Tube parameters were measured using anterior segment optical coherence tomography (AS-OCT). Results: The ECD loss during 2 years of follow-up was significantly lower in the guided AGV implantation (gAGV) group than in the non-guided implantation (ngAGV) group, and the rate of ECD change was -0.62 ± 1.23 and -1.42 ± 1.57 %/month in the gAGV and ngAGV groups, respectively (p = 0.003). The mean tube–cornea distance (TCD) and mean tube–cornea angle (TCA) were significantly greater in the gAGV group than in the ngAGV group. The frequency of tube repositioning within 2 years after surgery was 0 % in the gAGV group and 12.66 % in the ngAGV group (p = 0.005). Conclusions: The use of a guidance technique can reduce corneal endothelial loss during the first 2 years after AGV implantation in the AC. The tube was positioned at a more distant and wider angle from the cornea in the eyes of the gAGV group, which may have contributed to the reduced need for tube repositioning to prevent corneal decompensation.