UNASSIGNED: To present the outcomes of Ahmed glaucoma valve (AGV) implantation in uveitic glaucoma (UG) in a tertiary eye center in Riyadh, Saudi Arabia.
UNASSIGNED: A retrospective review of all UG patients who underwent AGV implantation at a single, tertiary care eye center from January 2008 to December 2018. The main outcome measures were change in mean intraocular pressure (IOP), number of antiglaucoma medications, overall success rate in different follow-up periods, complete and qualified success from last follow up, and complications. The success of the treatment was defined as patients achieving intraocular pressure (IOP) levels between 6- and 21-mm Hg with or without additional antiglaucoma medications and/or a minimum of 20% reduction from baseline IOP.
UNASSIGNED: The study included 74 patients (86 eyes), with a mean follow-up of 4.9 ± 2.9 years. The mean IOP was 32.2 ± 8.5 mmHg at baseline and 16.3 ± 6.6 mmHg at the last follow-up (p < 0.001). The mean number of antiglaucoma medications decreased from 3.5 ± 0.7 preoperatively to 1.3 ± 1.4 at the last follow-up (p < 0.001). Overall survival rates at 1, 3, 5, and 10 years were 96.5%, 92.7%, 91%, and 56.9%, respectively. Complete and qualified success rates were 37.9% and 48.3% at the end of follow up, respectively. The rate of postoperative complications was 56%, of which 18 eyes (20%) required surgical revision. Bivariate Cox proportional hazards regression analysis did not reveal any factors significantly associated with failure.
UNASSIGNED: AGV is safe and effective in providing intermediate-term IOP control in UG patients. Complications reported in our cohort were mostly transient and conservatively treated.

UNASSIGNED: Glaucoma is a leading cause of irreversible blindness globally and for decades, Molteno and Ahmed glaucoma implants, operating on different mechanisms, have been used to treat complicated glaucoma with varying success.
UNASSIGNED: To assess the safety and efficacy of the Molteno glaucoma implant (MGI) versus the Ahmed glaucoma valve (AGV) in patients with complicated glaucoma.
UNASSIGNED: We comprehensively searched PubMed, Google Scholar, Cochrane Library and Science Direct) from inception till July 2023 and studies comparing patients with MGI and those with AGV in patients with complicated glaucoma. The primary outcome was intra-ocular pressure reduction at different time intervals. Secondary outcomes included surgical success rate, hypertensive phase, anti-glaucoma medication (AGM) and total complications.
UNASSIGNED: In this meta-analysis, four studies were included with a patient population of 257 with refractory, neovascular or advanced uncontrolled glaucoma. Postoperative intra-ocular pressure reduction did not show significant difference between the two groups (MD: -1.34, 95% CI [-2.78, 0.09]). From the secondary outcomes, surgical success rate (RR: 0.88, 95% CI [0.51,1.53]), hypertensive phase (RR: 0.74, 95% CI [0.39,1.40]) were insignificant. Postoperative anti-glaucoma medication (MD: -0.07, 95% CI [-0.79, -0.65] and total complications (RR:1.36, 95% CI [1.07, 1.72]) were significant.
UNASSIGNED: No significant difference was observed between the patients with MGI and AGV for the primary outcome. From the secondary outcome, AGV was associated with reduced anti-glaucoma medication use and significantly lowered the number of complications.
UNASSIGNED: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=475539, identifier CRD42023475539.

UNASSIGNED: The aim of this study was to compare the outcomes of Ahmed glaucoma valve implantation (AGVI) in neovascular glaucoma (NVG) due to proliferative diabetic retinopathy (PDR) with or without a pars plana vitrectomy (PPV) history and to analyze the factors affecting surgical failure.
UNASSIGNED: Patients with NVG secondary to PDR undergoing AGVI at a single center were reviewed retrospectively. The surgical failure rates and post-operative complications were compared between eyes with (PPV-AGVI group) and without previous PPV (AGVI group). Failure was defined as loss of light perception or intraocular pressure (IOP) >17 mmHg despite maximum medication, or need of additional intervention for IOP control or for the management of complications. Survival analysis was investigated by Kaplan-Meier test. The possible factors for failure were analyzed with logistic regression analysis.
UNASSIGNED: The failure rates were 21.9% during the mean follow-up of 27.56±15.38 months and 14.3% during 23.63±12.38 months, in PPV-AGVI group (n=32) and in AGVI group (n=49), respectively (p=0.37). The frequency of complications and surgical intervention need for management of post-operative complications was similar between groups (p>0.05). There was no significant difference in survival analysis (p=0.13). The history of intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection before AGVI was significantly associated with failure (odds ratio = 26.941, p=0.02).
UNASSIGNED: The results of AGVI performed with long scleral tunnel technique were comparable in terms of failure rates, between NVG patients with and without previous diabetic vitrectomy. The only significant factor for failure was intravitreal anti-VEGF pre-treatment. This may be related to the necessity of anti-VEGF therapy in aggressive PDR, and also, anti-VEGF agents may increase fibrosis in the anterior chamber angle.

OBJECTIVE: To evaluate the changes in thickness of tissues, specifically the pericardium patch graft (PPG) covering the silicone tube in Ahmed Glaucoma Valve (AGV) surgery.
METHODS: Prospective observational study.
METHODS: This study included cases with refractory glaucoma that underwent AGV implantation with PPG coverage. Conjunctival epithelium, stroma and PPG thickness covering the tube were measured using anterior segment optical coherence tomography (AS-OCT) at 1, 6 and 12 months. Additionally, the same measurements were taken 1500 µm away from the tube as a control for the central measurements.
RESULTS: Twenty-seven eyes of 27 patients were evaluated in the study. Although PPG thickness decreased significantly in both regions, the amount of reduction was more pronounced centrally. Centrally, the reduction rate was 21.2% and 34.8% during the 1-6 months period and 6-12 months period, while peripherally it was 3.5% and 5.1%, respectively. No change was observed in the thickness of the epithelium during the follow-up period. There was a significant thinning of the stroma in the central and peripheral regions during the 1-6 months period (30.5% and 17%, respectively). No cases of exposure were observed during the follow-up period.
CONCLUSIONS: Although the most evident thinning of the layers covering the tube was observed in the early postoperative period, PPG showed a stable decrease even in the late period. The progressive reduction in the PPG thickness observed also in the peripheral region indicates that factors beyond mechanical forces contribute to this degenerative process. AS-OCT could be a valuable non-invasive tool in clarifying this process.

OBJECTIVE: To present the short-term outcomes of our novel technique, the suture-assisted method, in long scleral tunnel Ahmed Glaucoma Valve (AGV) implantation.
METHODS: This retrospective study included glaucoma patients who underwent AGV implantation using the suture-assisted long scleral tunnel method and were fellowed for at least 6 months between January 2022 and November 2022. Preoperative and postoperative assessments included best-corrected visual acuity (BCVA), intraocular pressure (IOP), anterior and posterior segment examinations, anti-glaucomatous medications, and intraoperative and postoperative complications were also evaluated.
RESULTS: Eight eyes of seven patients were included in the study. The mean age was 52.25 ± 29.38 years (r:8-76 years), and there were 5 female and 2 male patients. The mean follow-up duration period was 8.62 ± 2.50 months (r:6-12 months). The mean IOP was 27.12 ± 3.48 mmHg preoperatively and 11.62 ± 3.48 mmHg on postoperative on 1st day, 11.62 ± 3.20 mmHg at 1st week, 18.75 ± 8.94 mmHg at 1st month, 16.62 ± 2.72 mmHg at 3rd month, 16.12 ± 3.75 mmHg at 6th month. Postoperative hyphema was observed in one eye, and tenon cyst excision was performed in two eyes. No tube exposure was observed in any eye during the follow-up period. No hypotony-related complications were observed during follow-up.
CONCLUSIONS: We believe that suture-asissted application of the long scleral tunnel method not only prevents tube exposure but also facilitates the passage of the AGV silicone tube through the scleral tunnel, reducing the surgical time contributing to a decreased the risk of infection.

OBJECTIVE: To assess the characteristics of blebs formed after Ahmed glaucoma valve (AGV) surgery in dogs using ultrasound biomicroscopy (UBM) and to analyze their correlation with postoperative intraocular pressure (IOP).
METHODS: 16 eyes (13 dogs) were diagnosed with primary angle-closure glaucoma and were followed up after AGV surgery from June 2021 to September 2023.
METHODS: In this prospective study, UBM examinations were performed to assess bleb characteristics, including bleb wall thickness and reflectivity. IOP at the time of UBM imaging and the duration from AGV surgery to UBM imaging were recorded. Histological examination of an enucleated eye removed due to uncontrolled IOP leading to blindness was also conducted.
RESULTS: A significant correlation was observed between IOP and relative reflectivity (Pearson r = 0.60; P = .01), and a negative correlation was observed between bleb wall thickness and relative reflectivity (Pearson r = -0.72; P = .002). No significant correlation was observed between the duration from AGV surgery to UBM imaging and either bleb wall thickness or relative reflectivity, respectively. Histological examination of the enucleated eye revealed collagen-rich fibrous encapsulation of the bleb wall, including myofibroblasts that exhibited positive α-smooth muscle actin immunostaining.
CONCLUSIONS: In dogs that underwent AGV surgery, less dense, thick-walled blebs on UBM tended to maintain IOP within the normal range. However, denser, thinner-walled blebs showed IOP levels above the normal range despite the use of antiglaucoma medications. UBM is a useful tool for evaluating bleb characteristics and their influence on IOP regulation after AGV surgery in dogs.

UNASSIGNED: This study aims to present two different types of giant bleb formation following Ahmed Glaucoma Valve (AGV) implantation: an anterior enlarged giant bleb and a posterior enlarged giant bleb.
UNASSIGNED: In Case 1, a 70-year-old Japanese male underwent AGV implantation for neovascular glaucoma in his right eye (OD). Preoperatively, the patient\'s intraocular pressure (IOP) and best corrected visual acuity (BCVA) were 23 mmHg and 0.6, respectively, OD, while using 3 antiglaucoma topical medications. Two months post-surgery, the patient began experiencing double vision. Slit lamp evaluation revealed no abnormalities, IOP and BCVA were 24.0 mmHg and 0.8, respectively, OD. A posteriorly enlarged bleb in the superotemporal quadrant OD was found to be causing displacement on T2-weighted orbital MRI. The patient underwent surgical excision of the anterior bleb wall. By three weeks post-surgery, the double vision resolved; IOP and BCVA were 17 mmHg and 0.7, respectively, and a normal bleb in the slit lamp evaluation was identified OD. In Case 2, a 10-year-old Japanese female underwent AGV implantation for childhood glaucoma associated with congenital cataract OD. Preoperatively, IOP and BCVA were 30 mmHg and 0.5, respectively, OD, while using 3 antiglaucoma topical medications. She underwent pars plana vitrectomy (PPV) in addition to AGV implantation. Seven months post-surgery, slip lamp evaluation revealed an anteriorly enlarged giant bleb that only cause her a cosmetic concern.
UNASSIGNED: There are two types of giant bleb formation following AGV implantation based on the direction of the enlargement: an anterior enlarged giant bleb and a posterior enlarged giant bleb. The introduction of this classification contribute to better understanding and management of this unusual surgical complication.

OBJECTIVE: To investigate the clinical outcomes of Ahmed glaucoma valve (AGV) implantation in primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEXG).
METHODS: The patients who underwent AGV implantation for POAG and PEXG between January 2015 and December 2021 in a single tertiary center eye clinic were reviewed retrospectively. Thirty-one eyes with the diagnosis of POAG constituted Group 1 and 40 eyes with the diagnosis of PEXG constituted Group 2. The primary outcome measures were intraocular pressure (IOP) changes after AGV implantation and surgical success at the last visit. We evaluated complete and qualified surgical success using the following three criteria: (1) IOP ≤ 21mmH g, (2) IOP ≤ 18 mmHg, and (3) IOP ≤ 15 mmHg, as well as the absence of any serious complications, such as light perception loss and phthisis bulbi, and additional de novo glaucoma surgery.
RESULTS: The mean follow-up times were 25.2 (± 21.4) months and 27.6 (± 19.8) months for Groups 1 and 2, respectively (p > 0.05). In Groups 1 and 2, the mean preoperative IOPs were 31.9 ± 9.4 mmHg and 32.3 ± 8.4 mmHg, respectively, which significantly reduced to 14.5 ± 0.7 mmHg and 11.6 ± 0.6 mmHg, respectively at the last postoperative visit (p < 0.001 for both). The mean IOP value at the last visit was statistically significantly lower in Group 2 (p = 0.006). At the last visit, the number of eyes with qualified success according to criteria 1, 2, and 3 was 26 (83.9%), 25 (80.6%), and 18 (58.1%), respectively, in Group 1 and 39 (97.5%), 39 (97.5%), and 32 (80%), respectively, in Group 2. The comparison of the qualified success rates showed statistically significantly higher rates in Group 2 for criterion 2 (p = 0.038).
CONCLUSIONS: AGV implantation had high success rates in both POAG and PEXG, but at the final visit, lower IOP levels were reached in the latter.

OBJECTIVE: The objective of the study was to evaluate visual outcomes between medical treatment alone (MED) and Ahmed glaucoma valve implantation (AGVI) in Shiba dogs with primary angle closure glaucoma (PACG).
METHODS: Records of 65 Shiba dogs (104 eyes) with PACG were retrospectively reviewed. Vision was assessed qualitatively using both the menace response and maze testing. The significance of age, sex, intraocular pressure (IOP), and duration of clinical signs (≤72 h or >72 h) at first presentation (V1) was assessed. Eyes with vision at V1 were divided into groups according to subsequent treatment method (MED versus AGVI), and vision as a survival outcome was compared between group by the Kaplan-Meier method.
RESULTS: At V1, 65 eyes (62.5%) of 54 dogs had vision. There was no statistically significant difference in age or sex on the presence of vision at V1. Median IOP was higher in blind (52 mmHg) compared to sighted eyes (28 mmHg) (p < .001). Eyes presenting in ≤72 h of the onset of clinical signs were more likely to have vision (86.7%) compared to those presenting after 72 h (44.1%) (p < .001). By the Kaplan-Meier analysis, the cumulative visual retention rate was significantly higher with AGVI than with MED (69.2% vs. 7.7%; p < .01) at 12 months. The median time to visual loss was 39.9 months with AGVI vs. 1.7 months with MED.
CONCLUSIONS: AGVI resulted in better visual outcomes than MED and should be considered in Shiba dogs with PACG that are visual at the time of presentation and suitable for surgery.

UNASSIGNED: To evaluate the outcomes of surgical intervention in eyes with neovascular glaucoma (NVG) and poor vision, comparing the Ahmed glaucoma implant with cyclophotocoagulation (CPC).
UNASSIGNED: This study is a double-armed cohort retrospective review of medical records of patients with NVG who had a visual acuity of 20/200 or less and underwent one of the two procedures as a primary intervention: Ahmed glaucoma valve (AGV) or cyclophotocoagulation (CPC). The study was conducted at King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia, from January 2014 to June 2019, with a total study period of 1 year. The main outcome measures included the surgical success rate, changes in intraocular pressure (IOP), the number of antiglaucoma medications, corrected distance visual acuity, and the reoperation rate for glaucoma.
UNASSIGNED: The preoperative IOP was 40.4 ± 10.6 mmHg (Median 40) in the CPC group and 39.4 ± 10.2 mmHg (Median 40) in the AGV group (P = 0.6). At 1 year, the IOP ranged from 12.5 to 28 mmHg (Median 18) in the CPC group and 14 to 21.5 mmHg (Median 17) in the AGV group (P = 0.016). Survival analysis showed a 51% success rate in the CPC group and an 89% success rate at 1 year in the AGV group (p>0.0001).
UNASSIGNED: CPC and AGV procedures yielded good outcomes with similar IOP levels 12 months after the surgery. However, AGV demonstrated a higher overall success rate and a lower medication requirement than CPC.