BACKGROUND: Ahmed glaucoma valve (AGV) is a common surgical method for the treatment of refractory glaucoma.Aurolab aqueous drainage implant (AADI) is a novel surgical method which has been applied in clinical practice in recent years.
OBJECTIVE: The purpose of this study was to compare the efficacy and safety of the AADI and the AGV for the treatment of refractory glaucoma.
METHODS: We comprehensively searched four databases, including PubMed, Embase, Web of Science, and the Cochrane Library databases, selecting the relevant studies. The continuous variables, namely, intraocular pressure reduction (IOPR) and a reduction in antiglaucoma medication (AGMR), were pooled by the weighted mean differences (WMDs), and the dichotomous outcomes, including success rates and complications, were pooled by the odds ratio (OR).
RESULTS: A total of 825 eyes from 820 patients from six studies were included. The WMDs of the IOPR between the AADI and the AGV implant were 0.58 (95% CI: 0.07-1.09) at 3 months, 0.44 (95% CI: 0.11-0.77) at 6 months, 2.20 (95% CI: 0.63-3.77) at 12 months, and 3.24 (95% CI: 1.73-4.75) at follow-up endpoint. Significant difference was detected between the two groups at any point in time. The WMDs of the AGMR between the AADI and the AGV implant were 0.87 (95% CI: 0.61-1.13) at 6 months, 1.04 (95% CI: 0.66-1.42) at 12 months, and 0.93 (95% CI: 0.52-1.34) at the follow-up endpoint; the differences reached statistical significance at any point in time. The pooled ORs comparing the AADI with the AGV were 3.64 (95% CI: 2.44-5.45) for the complete success rate and 1.72 (95% CI: 1.24-2.39) for qualified success rate; significant difference was detected between the two groups. There were no significant differences between the AADI and the AGV implant on the rates of adverse events.
CONCLUSIONS: The AADI is more effective in both its surgical success rate and reducing IOP and AGM. And the two implants may have comparable incidences of adverse events.

This study aimed to describe the clinical features, surgical management of the eyelid and ocular surface, and outcomes of 16 patients implanted with a Boston type I keratoprosthesis (KPro).
A retrospective, single-center, consecutive case series of 16 patients with Stevens-Johnson syndrome (1), ocular chemical burns (12), and ocular thermal burns (3) implanted with KPro was studied. All subjects were men aged 27-51 years. Surgical treatment and outcomes for eyelid malposition, symblepharon, and glaucoma were assessed.
From September 2010 to February 2019, 29 patients were admitted to Zhongshan Ophthalmic Center for KPro implantation, of whom 16 (55%) required eyelid or ocular surface surgeries to maintain hydration and protect the corneal tissue, which is vulnerable to epithelial defects. Forty-one adnexal surgical procedures were performed. The most common indication for surgery was symblepharon, and the most frequent procedures were symblepharon lysis with ocular mucous membrane grafts and amniotic membranes (7) and full-thickness skin grafts to the eyelids (7). Preoperative conjunctival injection and corneal staining were documented in 9 (56%) and 8 (50%) eyes, respectively, and at up to 4 months postoperative follow-up (the last adnexal surgery before KPro) were recorded in 3 (19%, p = 0.03) and 2 (12%, p = 0.02) eyes, respectively. Glaucoma drainage devices were inserted in six patients. One patient with Stevens-Johnson syndrome underwent FP7 Ahmed glaucoma valve (AGV) implantation inferotemporally and developed plate exposure 2 months postoperatively. Five patients underwent FP8 AGV implantation with tube insertion into the vitreous cavity due to the scarred conjunctiva and limited subconjunctival space. In the study period, intraocular pressure (IOP) was in the normal range, and no tube or plate exposure was observed.
The ocular environment is critical for successful KPro surgery. A multidisciplinary approach for any lid and ocular surface abnormality in ocular burns or Stevens-Johnson syndrome is important to improve the quality of the ocular surface and accommodate KPro and AGV, which is vital for maintaining vision after KPro surgery. FP8 AGV may be feasible for IOP control in adult KPro cases with restricted subconjunctival space.

OBJECTIVE: To describe the clinical results of combined Ahmed valve implantation and 23-gauge vitrectomy for medically uncontrolled neovascular glaucoma (NVG) secondary to proliferative diabetic retinopathy (PDR).
METHODS: The medical records of medically uncontrolled NVG patients with PDR who underwent Ahmed valve implantation and 23-gauge vitrectomy between March 2016 and December 2018 were reviewed. Enrolled patients had at least 6-month follow-up. Panretinal photocoagulation (PRP), anti-vascular endothelial growth factor, surgery and medication history were documented.
RESULTS: Eleven eyes of 11 patients were included in our study. The visual acuity improved in 8 eyes and remained unchanged in 3 eyes. The preoperative intraocular pressure (IOP) was significantly decreased at the last follow-up (48.8±4.3 to 17.0±1.5 mm Hg, P<0.001). All eyes needed three topical anti-glaucomatous medications before surgery, but the number was significantly reduced to 0.72±0.19 at the last visit (P<0.001). Four eyes had choroidal detachment and 3 eyes had minor hyphemia, all of which gradually resolved without treatments in one week.
CONCLUSIONS: Ahmed glaucoma valve implantation combined with 23-gauge vitrectomy might be a safe and alternative treatment for NVG with PDR.

To evaluate the efficacy of Ahmed glaucoma valve (AGV) implantation in treating neovascular glaucoma (NVG) and analyze the factors influencing the surgical success rate, a retrospective investigation of 59 NVG patients (66 eyes) who underwent AGV implantation was conducted at Jiangsu Province Hospital, China, from January 2014 to June 2018. Intraocular pressure (IOP), visual acuity, surgical success rates, medications, and complications were monitored at post-operative 1 day, 1 week, 1, 3, 6 and 12 months. Surgical success criteria were defined as 6 mm Hg < IOP < 21 mmHg with or without additional medications. Results showed average IOP was statistically significant between pre-operative visit and each follow-up visit (all P<0.05). At 12 months, the success rate was 66.7%. Multiple stepwise regression analysis suggested that age, panretinal photocoagulation (PRP), complications and hyphema were significant factors influencing the surgical success rate (all P<0.05). Thus, we conclude that AGV implantation is effective and safe for treatment of NVG. Surgical success is dependent on age, PRP, complications, and hyphema.

BACKGROUND: To investigate the occurrence of ciliochoroidal detachment (CCD), its risk factors and its impact on the success rate after Ahmed glaucoma valve (AGV) implantation.
METHODS: This is a retrospective observational study carried out at Eye Hospital of Wenzhou Medical University, Zhejiang, China. Patients with uncontrolled glaucoma who underwent AGV implantation alone or combined with phacoemulsification (AGV-Phaco) in the hospital from April 1, 2013 to July 31, 2016 were included. The preoperative and postoperative CCD was defined when the detachment between ciliary body and choroid was detected by the ultrasound biomicroscopy (UBM) and anterior segment optical coherence tomography (AS-OCT) respectively. The main outcomes included the incidence of CCD and the success rate at 6 months after surgery.
RESULTS: In total, 97 male and 56 female patients were included. CCD was observed in 92 (57.8%) eyes. The glaucoma diagnosis in the Non-CCD and CCD group included primary open angle glaucoma (21(31.3%) vs 33(35.9%)), primary angle closure glaucoma (10(14.9%) vs 13(14.1%)), secondary glaucoma (25(37.3%) vs (28(30.4%)) and so on. The preoperative median IOP (interquartile range) were 21.7(16.0,32.0) mmHg and 23.0(16.0,33.0) mmHg in the Non-CCD group and CCD group. Previous surgical history (95% confidence interval (CI), 1.24 to 13.34; odds ratio (OR) 4.06; p = 0.02) and shorter axial length (95% CI, 0.62 to 0.97 OR 0.78; p = 0.02) were the two risk factors of CCD. The success rate between the CCD and Non-CCD group was not significantly different (64.3% vs 62.5%, p = 0.86) at 6 months.
CONCLUSIONS: The incidence of CCD is 57.8% after AGV surgery. Eyes with previous surgical procedure was prone to CCD occurrence and longer axial length was protective against CCD. But at 6 months postoperatively, CCD did not reduce the success rate of AGV surgery and may not be a worrisome complication.

Excessive fibrosis is the topmost factor for the defeat of surgical glaucoma drainage device (GDD) implantation. Adjuvant drug approaches are promising to help reduce the scar formation and excessive fibrosis. Opal shale (OS), as a natural state and noncrystalline silica substance with poriferous nature and strong adsorbability, is highly likely to undertake drug loading and delivery. Here, we employed OS microparticles (MPs) by ultrasound and centrifugation and presented an innovative and improved GDD coated with OS MPs, which were loaded with mitomycin C (MMC). MMC-loaded OS MPs were physically absorbed on the Ahmed glaucoma valve surface through OS\' adsorbability. About 5.51 μg of MMC was loaded on the modified Ahmed glaucoma valve and can be released for 18 days in vitro. MMC-loaded OS MPs inhibited fibroblast proliferation and showed low toxicity to primary Tenon\'s fibroblasts. The ameliorated drainage device was well tolerated and effective in reducing the fibrous reaction in vivo. Hence, our study constructed an improved Ahmed glaucoma valve using OS MPs without disturbing aqueous humor drainage pattern over the valve surface. The modified Ahmed glaucoma valve successfully alleviated scar tissue formation after GDD implantation surgery.

The curative effects of Ex-PRESS implantation and Ahmed glaucoma valve (AGV) implantation in the treatment of refractory glaucoma were compared. A total of 68 patients (76 eyes) with refractory glaucoma treated were randomly divided into Ex-PRESS group and AGV group. Results showed that the intraocular pressure IOP in both Ex-PRESS group and AGV group after operation was significantly decreased compared with that before operation (P<0.001). At 3, 6 and 9 months after operation, IOP in Ex-PRESS group was significantly lower than that in AGV group (P<0.05). At the end of follow-up, BCVA of patients in both groups after operation was slightly decreased compared with that before operation (P>0.05). There was no statistically significant difference in BCVA between the two groups of patients (P>0.05). Moreover, the corneal endothelial cell counts of patients in both groups after operation were obviously decreased compared with those before operation (P<0.05). The number of anti-glaucoma drugs applied was decreased from 3.53±0.86 to 0.55±0.60 in Ex-PRESS, and from 3.24±0.88 to 0.89±0.73 in AGV group. At the end of follow-up, the number of anti-glaucoma drugs applied in Ex-PRESS group was smaller than that in AGV group (P<0.05). There was no statistically significant difference in success rate of operation between the two groups at the end of follow-up (log-rank test; P>0.05). Finally, the incidence rates of postoperative complications and surgical intervention rates had no statistically significant differences between the two groups. Ex-PRESS implantation is a safe and effective treatment for refractory glaucoma, characterized by simple operation, small trauma and less pain, which has an equivalent curative effect to AGV implantation; but its control effect on IOP after operation is superior to that of AGV, and the number of anti-glaucoma drugs applied after operation is small.

OBJECTIVE: To report long-term outcomes of secondary glaucoma due to uveitis treated with Ahmed glaucoma valve (AGV) implantation in a series of Chinese patients.
METHODS: The retrospective study included 67 eyes from 56 patients with uveitic glaucoma who underwent AGV implantation. Success of the treatment was defined as patients achieving intraocular pressure (IOP) levels between 6 and 21 mm Hg with or without additional anti-glaucoma medications and/or a minimum of 20% reduction from baseline IOP. The main outcome measurements included IOP, the number of glaucoma medications at 1, 3, 6, 12, 24, 36, 48 and 60mo after surgery, surgical complications, final best-corrected vision acuity (BCVA), visual field (VF) and retinal nerve fiber layer (RNFL).
RESULTS: The mean follow-up was 53.3±8.5 (range 48 to 60)mo. The cumulative probability of success rate was 98.5%, 95.5%, 89.6%, 83.6%, 76.1%, 70.1%, 65.7% and 61.2% at 1, 3, 6, 12, 24, 36, 48 and 60mo, respectively. IOP was reduced from a baseline of 30.8±6.8 to 9.9±4.1, 10.1±4.2, 10.9±3.7, 12.9±4.6, 13.8±3.9, 13.2±4.6, 12.3±3.5 and 13.1±3.7 mm Hg at 1, 3, 6, 12, 24, 36, 48 and 60mo, respectively (P<0.01). The number of postoperative glaucoma medications was significantly decreased compared with baseline at all time points during the study period (P<0.05). There was no significant difference between preoperative and postoperative BCVA. Remarkable surgical complications were not found after surgery. The VF and RNFL of the patients were stable after the surgery.
CONCLUSIONS: AGV implantation is safe and effect in terms of reducing IOP, decreasing the number of glaucoma medications, and preserving vision for patients with uveitic glaucoma.

OBJECTIVE: Vitreous hemorrhage is common in advanced neovascular glaucoma (NVG), which has poor visual prognosis. This study aimed to compare the efficacy of 23-G pars planar vitrectomy (PPV) combined with either Ahmed glaucoma valve (AGV) implantation or trabeculectomy after intravitreal ranibizumab (IVR) treatment for NVG with vitreous hemorrhage.
METHODS: This retrospective, nonrandomized study included 33 eyes of 33 patients with NVG with vitreous hemorrhage. After IVR treatment for 3-7 days, 18 eyes underwent PPV + AGV (AGV group) and 15 underwent PPV + trabeculectomy (trabeculectomy group). The success criterion was a postoperative intraocular pressure (IOP) of 6-21 mm Hg, with or without antiglaucoma medication.
RESULTS: Postoperative IOP decreased significantly in both groups, but the mean IOP after 12 months was significantly lower in the AGV group (16.92 ± 2.75 mm Hg) than the trabeculectomy group (21.50 ± 5.79 mm Hg; p = 0.018). The AGV group required fewer glaucoma medications than the trabeculectomy group. The cumulative probabilities of surgical success rates for the AGV and trabeculectomy groups at 12 months were 71.3% and 46.7%, respectively. No significant differences in postoperative complications were observed between the groups.
CONCLUSIONS: For NVG with vitreous hemorrhage, PPV with AGV implantation may reduce IOP more effectively than PPV with trabeculectomy.

OBJECTIVE: The purpose of this study was to evaluate the intermediate surgical results of Ahmed glaucoma valve (AGV) implantation in patients less than 7 years of age, with advanced primary congenital glaucoma who have failed previous surgeries.
METHODS: Consecutive patients with advanced primary congenital glaucoma that failed previous operations and had undergone subsequent AGV implantation were evaluated retrospectively. Surgical success was defined as 1) intraocular pressure (IOP) ≥6 and ≤21 mmHg; 2) IOP reduction of at least 30% relative to preoperative values; and 3) without the need for additional surgical intervention for IOP control, loss of light perception, or serious complications.
RESULTS: Fourteen eyes of eleven patients were studied. Preoperatively, the average axial length was 27.71±1.52 (25.56-30.80) mm, corneal diameter was 14.71±1.07 (13.0-16.0) mm, cup-to-disc ratio was 0.95±0.04 (0.9-1.0), and IOP was 39.5±5.7 (30-55) mmHg. The mean follow-up time was 18.29±10.96 (5-44, median 18) months. There were significant reductions in IOPs and the number of glaucoma medications (P<0.001) postoperatively. The IOPs after operation were 11.3±3.4, 13.6±5.1, 16.3±2.7, and 16.1±2.6 mmHg at 1 month, 6 months, 12 months, and 18 months, respectively. Kaplan-Meier estimates of the cumulative probability of valve success were 85.7%, 71.4%, and 71.4% at 6, 12, and 18 months, respectively. Severe surgical complications, including erosion of tube, endophthalmitis, retinal detachment, choroidal detachment, and delayed suprachoroidal hemorrhage, occurred in 28.6% cases.
CONCLUSIONS: AGV implantation remains a viable option for patients with advanced primary congenital glaucoma unresponsive to previous surgical intervention, despite a relatively high incidence of severe surgical complications.