Ahmed glaucoma valve implant: surgical technique and complications

Implantation of Ahmed glaucoma valve is an effective surgical technique to reduce intraocular pressure in patients affected with glaucoma. While in the past, the use of this device was reserved to glaucoma refractory to multiple filtration surgical procedures, up-to-date mounting experience has encouraged its use also as a primary surgery for selected cases. Implantation of Ahmed glaucoma valve can be challenging for the surgeon, especially in patients who already underwent previous multiple surgeries. Several tips have to be acquired by the surgeon, and a long learning curve is always needed. Although the valve mechanism embedded in the Ahmed glaucoma valve decreases the risk of postoperative hypotony-related complications, it does not avoid the need of a careful follow-up. Complications related to this type of surgery include early and late postoperative hypotony, excessive capsule fibrosis around the plate, erosion of the tube or plate edge, and very rarely infection. The aim of this review is to describe surgical technique for Ahmed glaucoma valve implantation and to report related complications.

A Review of the Ahmed Glaucoma Valve Implant and Comparison with Other Surgical Operations

The Ahmed glaucoma valve (AGV) is a popular glaucoma drainage implant used for the control of intraocular pressure in patients with glaucoma. While in the past AGV implantation was reserved for glaucoma patients poorly controlled after one or more filtration procedures, mounting evidence has recently encouraged its use as a primary surgery in selected cases. AGV has been demonstrated to be safe and effective in reducing intraocular pressure in patients with primary or secondary refractory glaucoma. Compared to other glaucoma surgeries, AGV implantation has shown favorable efficacy and safety. The aim of this article is to review the results of studies directly comparing AGV with other surgical procedures in patients with glaucoma.

Clinical outcomes of Ahmed glaucoma valve implantation in pediatric glaucoma

PURPOSE:

To evaluate the outcomes of Ahmed glaucoma valve implantation in refractory primary congenital glaucoma as well as primary procedure in aphakic glaucoma.

METHOD:

In this retrospective study, medical records of patients who underwent Ahmed glaucoma valve implantation for refractory glaucoma and aphakic glaucoma were reviewed. Primary outcome measures were the surgical success defined as intraocular pressure ≤21 mm Hg and decreased ≥20% and no secondary glaucoma surgery. Secondary outcome measures were the number of glaucoma medications, complications, best corrected visual acuity, and intraocular pressure.

RESULTS:

A total of 62 eyes of refractory primary congenital glaucoma patients (group 1) and 33 eyes of aphakic glaucoma patients (group 2) were included in our study. Mean follow-up was 51 ± 33 months in group 1 and 49 ± 41 months in group 2 (p = 0.82). The cumulative probability of success was 90% in both groups at the first year; however, the success rate was 52.5% in group 1 and 71.5% in group 2 at 5 years' follow-up visit. In group 1, the mean intraocular pressure ± standard deviation was 33.1 ± 8.6 mm Hg at the baseline and decreased to 17.1 ± 5.3 mm Hg at 1 year and 18.5 ± 6.4 at 3 years postoperatively (all p's < 0.001). Corresponding values for group 2 were 28.9 ± 6.1, 15.2 ± 4.6, and 16.0 ± 5.9 mm Hg, respectively (all p's < 0.001). The baseline number of glaucoma medications was 3 ± 0.7 that decreased to 2 ± 0.8 at final follow-up (p = 0.02).

CONCLUSION:

Ahmed glaucoma valve implantation has a moderate success rate in the management of refractory primary congenital glaucoma with an increased chance of tube-related complications. The surgical success rate is higher in case of primary Ahmed glaucoma valve implant for aphakic glaucoma with acceptable safety profile.

Efficacy of long scleral tunnel technique in preventing Ahmed glaucoma valve tube exposure through conjunctiva

PURPOSE

To evaluate the efficacy of long scleral tunnel technique used in Ahmed glaucoma valve (AGV) implantation in preventing tube exposure through conjunctiva.

MATERIALS AND METHODS

Patients of adult age, who were unresponsive to maximum medical treatment and underwent AGV implantation, were divided into two groups and investigated retrospectively. Group 1 consisted of 40 eyes of 38 patients that underwent surgery by long scleral tunnel technique and Group 2 consisted of 38 eyes of 35 patients that underwent implantation by processed pericardium patch graft method.

RESULTS

The mean age was 54.8 ± 14.6 years (range 26-68 years) and the mean follow-up duration was 46.7 ± 19.4 months (range 18-76 months) for the patients in Group 1, whereas the mean age was 58.6 ± 16.7 years (range 32-74 years) and mean follow-up period was 43.6 ± 15.7 months (range 20-72 months) for the patients in Group 2 (p > 0.05). In the course of follow-up, tube exposure was detected in one (2.5%) eye in Group 1 and in three (7.9%) eyes in Group 2 (p = 0.042).

CONCLUSION

Long scleral tunnel technique is beneficial in preventing conjunctival tube exposure in AGV implantation surgery.

A prospective randomized controlled study of Aurolab aqueous drainage implant versus Ahmed glaucoma valve in refractory glaucoma: A pilot study

PURPOSE

To study the efficacy of the Aurolab aqueous drainage implant (AADI) compared to Ahmed glaucoma valve (AGV) in patients with refractory glaucoma.

METHODS

This was a prospective, randomized controlled trial. Thirty-eight adult patients (>18 years) scheduled for a glaucoma drainage device (GDD) were randomized into two groups to receive either AGV or AADI. Primary outcome measures: intraocular pressure (IOP) control and requirement of antiglaucoma medications; secondary outcome measures: final best correct visual acuity (log MAR), visual field (Visual field index [VFI], mean deviation [MD] and pattern standard deviation [PSD]), postoperative complications and additional interventions. Complete success was defined as IOP ≥5-≤18 mmHg without antiglaucoma medications/laser/additional glaucoma surgery or any vision threatening complications.

RESULTS

There were 19 age and sex-matched patients in each group. Both groups had comparable IOP before surgery (P = 0.61). The AGV group had significantly lower IOP compared to AADI group (7.05 ± 4.22 mmHg vs 17.90 ± 10.32 mmHg, P = <0.001) at 1 week. The mean postoperative IOP at 6 months was not significantly different in the two groups (13.3 ± 4.2 and 11.4 ± 6.8 mmHg respectively; P = 0.48). At 6 months, complete success rate according to antiglaucoma medication criteria was 78.94% in AADI and 47.36% in AGV groups. AGV group required 1.83 times more number of topical medications than AADI group. There was no significant difference in early (P = 0.75) and late (P = 0.71) postoperative complications in the AADI and AGV group. The complete success rate was higher in AADI group (68.42%) than AGV group (26.31%) (P = 0.034).

CONCLUSION

In this study, AADI appears to have comparable efficacy versus AGV implant with higher complete success rate at 6 months follow-up.

Efficacy of Ahmed Glaucoma Valve Implantation on Neovascular Glaucoma

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.

Ahmed glaucoma valve in children: A review

Pediatric glaucoma is potentially a blinding disease. Although goniotomy and trabeculotomy are associated with good early success rates, eventually 20% of these procedures fail and many children will require additional surgery to control the IOP in the long-term. In this review, we reported that adequate IOP control can be achieved with the placement of Ahmed glaucoma valve and can last 5 or more years. However, most patients will need one or more glaucoma medications at some point after surgery. In addition, the implants may be associated with pupillary irregularities, lenticular opacification as well as tube-related complications, particularly in the first year of life, as the globe is enlarging with age.

Clinical outcomes of Ahmed glaucoma valve implantation using tube ligation and removable external stents

PURPOSE

To investigate the immediate and long-term outcomes of Ahmed glaucoma valve (AGV) implantation with silicone tube ligation and removable external stents.

METHODS

This retrospective non-comparative study investigated the outcomes of AGV implantation with silicone tube ligation and removable external stents in 95 eyes (90 patients) with at least 12 months of postoperative follow-up. Qualified success was defined as an intraocular pressure (IOP) of <or=21 mmHg and >or=6 mmHg regardless of anti-glaucoma medication. Those who required additional glaucoma surgery, implant removal or who had phthisis bulbi were considered failures. Hypotony was defined as an IOP of <6 mmHg.

RESULTS

Mean IOP reduced from 37.1+/-9.7 mmHg preoperatively to 15.2+/-5.6 mmHg at 12 months postoperatively (p<0.001). Qualified success was achieved in 84.2% at 1 year. Hypotony with an IOP of <6 mmHg was seen in 8.4% and an IOP of <5 mmHg in 3.2% on the first postoperative day. No case of hypotony required surgical intervention. Suprachoroidal hemorrhage did not occur in this study. When stents were removed on the first postoperative day because of an insufficient IOP decrease, the mean IOP decreased significantly from 42.0 mmHg to 14.1 mmHg (p<0.001) after 1 hour. The most common complication was hyphema, which occurred in 17.9%.

CONCLUSIONS

Hypotony-related early complications requiring surgical intervention were reduced by ligation and external stents in the tube. In addition, early postoperative high IOPs were managed by removing external stents. The described method can prevent postoperative hypotony after AGV implantation and showed long-term success rates comparable to those reported previously.

Long-term outcomes of glaucoma drainage devices for glaucoma post-vitreoretinal surgery with silicone oil insertion: a prospective evaluation

PURPOSE

To evaluate long-term success of the Ahmed glaucoma valve (AGV) for refractory glaucoma after vitreoretinal surgery with silicone oil insertion.

METHODS

Prospective non-comparative evaluation of patients who underwent AGV insertion for management of post-vitreoretinal surgery glaucoma, post-silicone oil removal. Intraocular pressure (IOP), visual acuity, and glaucomatous neuropathy status were evaluated preoperatively and at multiple follow-up visits postoperatively. Success, using Kaplan-Meier analysis, was determined at the 12-month follow-up visit and at the last follow-up. Factors associated with failure were analysed.

RESULTS

Twenty-seven eyes of 27 patients with a mean age of 28.3 ± 15.2 years underwent a superior AGV implantation. The average follow-up after AGV implantation was 17.11 ± 8.36 months (range: 9-60 months). Kaplan-Meier survival analysis revealed a 62 % success at 12 months and 37 % at 5 years. A 48 % rate of complications was noted, 22 % of which were vision-threatening. Factors analysed, including patient age, interval between vitreoretinal surgery and silicone oil removal, interval between vitreoretinal surgery and AGV implantation, and phakic status, were not found to be associated with higher failure rates.

CONCLUSION

Long-term success of AGV implantation for glaucoma after vitreoretinal surgery with silicone oil insertion is better than that reported for trabeculectomy, though complication rates remain high.

Surgical outcomes of a new affordable non-valved glaucoma drainage device and Ahmed glaucoma valve: comparison in the first year

BACKGROUND

A new low-cost, indigenously manufactured, non-valved glaucoma drainage device (GDD) has been introduced and its design is based on the Baerveldt Glaucoma Device. We aim to demonstrate the efficacy and safety of this GDD (Aurolab aqueous drainage implant, AADI) vis-à-vis the valved device, Ahmed glaucoma valve (AGV), in the management of refractory glaucomas.

DESIGN

Retrospective, comparative, interventional.

PARTICIPANTS

Case review of consecutive patients who underwent GDD surgery by a single fellowship-trained surgeon at a Tertiary Centre between January 2014 and November 2016.

PRIMARY OUTCOME MEASURE

Intraocular pressure (IOP).

SECONDARY

Antiglaucoma medication (AGM), LogMAR best-corrected visual acuity (BCVA), complications.

RESULTS

A total of 88 eyes of 83 patients were included; 36 eyes received AGV and 52 AADI. Preoperative parameters were similar between groups. Median follow-up was 13 and 12 months for AADI and AGV, respectively. Overall success rate was higher in AADI (92.3%) vs AGV (80.5%) (p<0.001). The median IOP in mm Hg (Quartiles; IQR) (AADI 14 (10,15;5) vs AGV 16 (14,20;6)) and AGM (AADI: 0 (0,1;1) vs AGV 2 (1,2.75;1.75)) was significantly lower in the AADI group at last follow-up (p<0.001). LogMAR BCVA improved in both groups; complication rates (AADI 44.2% vs AGV 52.7%) were comparable (p=0.59).

CONCLUSIONS

Both procedures were effective in reduction of IOP and need for AGM. Nevertheless, overall success rate was higher in the AADI group and IOP and number of AGM required was significantly lower in the AADI group; this affordable GDD could have a tremendous impact in the management of refractory glaucomas in low-income to middle-income countries.

Outcomes of Ahmed glaucoma valve implantation in advanced primary congenital glaucoma with previous surgical failure

Purpose

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.

Patients and 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.

Conclusion

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.

The Results of the Use of Ahmed Valve in Refractory Glaucoma Surgery

The treatment of refractory glaucoma (RG) is challenging. The commonly adopted strategy in RG treatment is a glaucoma drainage device (GDD) implantation, which despite its radical nature may not always provide the desired intraocular pressure (IOP) levels for a long term. This review is based on the scientific literature on Ahmed glaucoma valve (AGV) implantation for refractory glaucoma. The technique of AGV implantation is described and data for both the types, FP7 and FP8 performance are presented. The outcome with adjunct antimetabolite and anti-VEGF drugs are also highlighted. An insight is given about experimental and histological examinations of the filtering bleb encapsulation. The article also describes various complications and measures to prevent them.

How to cite this article: Bikbov MM, Khusnitdinov II. The Results of the Use of Ahmed Valve in Refractory Glaucoma Surgery. J Curr Glaucoma Pract 2015;9(3):86-91.

Comparison of 1-year outcomes after Ahmed glaucoma valve implantation with and without Ologen adjuvant

Background

Many studies have investigated the clinical benefits of Ologen for trabeculectomy. However, its benefits for Ahmed glaucoma valve (AGV) implantation have not been investigated as extensively. The aim of this study was to compare the 1-year outcomes of AGV implantation with and without Ologen adjuvant for the treatment of refractory glaucoma.

Methods

This retrospective study included a total of 20 eyes of 20 glaucoma patients, who were followed for at least 1-year after undergoing AGV implantation. In 12 eyes of 12 patients, conventional AGV (CAGV) surgery was performed, while in 8 eyes of 8 patients, Ologen-augmented AGV (OAGV) implantation was performed. The outcomes were evaluated according to intraocular pressure (IOP) and the number of IOP-lowering medications. Complete success was defined as IOP ≤ 21 mmHg without medications throughout the 1-year follow-up period, and qualified success was defined as IOP ≤ 21 mmHg with or without medications throughout the 1-year follow-up period.

Results

The rate of complete success was significantly higher in the OAGV group (50.0%) than in the CAGV group (8.3%) (p = 0.035). There were no significant differences between the two groups in terms of qualified success or incidence of the early hypertensive phase. The IOP changes were similar between the groups within 1-year postoperatively, though the number of IOP-lowering medications was significantly lower in the OAGV group during the early hypertensive phase (p = 0.031, 0.031, and 0.025 at postoperative months 1, 2, and 3, respectively). When subjects were divided into groups according to the occurrence of the early hypertensive phase, the group with early hypertensive phase was more likely to use IOP-lowering medications at postoperative 6 months and 1 year (p = 0.002 and 0.005, respectively).

Conclusions

OAGV surgery shows encouraging results for patients with refractory glaucoma, specifically with respect to the achievement of complete success and the reduction of the number of IOP-lowering medications during the early hypertensive phase. Furthermore, our results suggest that occurrence of the early hypertensive phase is predictive of which patients will require IOP-lowering medications at postoperative 6 months and 1 year.

Short term outcome of Ahmed glaucoma valve implantation in management of refractory glaucoma in a tertiary hospital in Oman

Background:

We present outcomes of Ahmed Glaucoma Valve (AGV) implantation in treating refractory glaucoma in a tertiary hospital in Oman. Refractory glaucoma was defined as previously failed conventional glaucoma surgery and an uncontrolled intraocular pressure (IOP) of more than 21 mm Hg despite treatment with three topical and/or oral therapy.

Materials and Methods:

This historical cohort study was conducted in 2010. Details of medical and surgical treatment were recorded. Ophthalmologists examined eyes and performed glaucoma surgeries using AGV. The best corrected distant vision, IOP, and glaucoma medications were prospectively reviewed on 1^st day, 1^st, 6^th, 12^th week postoperatively, and at the last follow up.

Result:

Glaucoma specialists examined and treated 40 eyes with refractory glaucoma of 39 patients (20 males + 19 females). Neo-vascular glaucoma was present in 23 eyes. Vision before surgery was <3/60 in 21 eyes. At 12 weeks, one eye had vision better than 6/12, seven eyes had vision 6/18 to 6/60, and eight eyes had vision 6/60 to 3/60. Mean IOP was reduced from 42.9 (SD 16) to 14.2 (SD 8) and 19.1 (SD 7.8) mmHg at one and 12 weeks after surgery, respectively. At 12 weeks, five (12.5%) eyes had IOP controlled without medication. In 33 (77.5%) eyes, pressure was controlled by using one or two eye drops. The mean number of preoperative anti-glaucoma medications (2.38; SD 1.1) was reduced compared to the mean number of postoperative medications (1.92; SD 0.9) at 12 weeks.

Conclusion:

We succeeded in reducing visual disabilities and the number of anti-glaucoma medications used to treat refractory glaucoma by AGV surgery.

Ahmed Valves vs Trabeculectomy Combined with Pans Plana Vitrectomy for Neovascular Glaucoma with Vitreous Hemorrhage

Purpose

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.

Long-term success of ahmed glaucoma valve in refractory glaucoma

AIM

To evaluate the long-term results and complications of ahmed glaucoma valve (AGV) implantation in refractory glaucoma.

METHODS

A retrospective review of 13 patients (13 eyes) with refractory glaucoma who underwent AGV implantation and had a minimum follow-up of 18 months was performed. All patients underwent a complete ophthalmologic examination and intraocular pressure (IOP) measurement before surgery and at 1 month, 3 months, 6 months, 1 year after surgery and yearly afterwards. Complications and the number of antiglaucoma medications needed were recorded.

RESULTS

Mean age was 27.3±16.0 years. All eyes (100%) had at least one prior incisional surgery. Mean follow-up was 61.3±30.8 months. IOP was reduced from a mean of 35.0 ±7.0mmHg to 18.2±7.9mmHg at 12 months and to 17.0±4.1mmHg at 96 months (P<0.05) with a lower number of medications from baseline, 76.9% patients required additional procedures to achieve the success criteria set by previously published series. The most common complications were encapculated cyst formation in eight eyes (61.5 %) and tube exposure in four eyes (30.8%).

CONCLUSION

Encapsulated cyst formation was the most common complication which hindered succesful IOP control after AGV implant insertion for refractory glaucoma. Despite cyst excision with anti-fibrotic agents, successful IOP reduction was not achieved in 76.9% of the patients without antiglaucoma medication.

Intravitreal bevacizumab and Ahmed glaucoma valve implantation in patients with neovascular glaucoma

AIM

To explore the efficacy of preoperative intravitreal bevacizumab (IVB) injection combined with Ahmed glaucoma valve (AGV) implantation in the treatment of neovascular glaucoma (NVG).

METHODS

This retrospective study included 35 eyes from 35 patients who underwent preoperative IVB and AGV implantation for treatment of NVG. Findings such as intraocular pressure (IOP) number of anti-glaucoma medications, visual acuity (VA), surgical success rates, and complications were recorded.

RESULTS

After AGV implantation, IOP was 18.2±4.0 mm Hg, 15.5±3.3 mm Hg and 9.8±2.6 mm Hg at 6, 12 and 36mo, significantly decreased compared with pre-IOP (P<0.01). The number of anti-glaucoma medications was 0.9±0.5, 0.8±0.9 and 0.8±0.6 at 6, 12 and 36mo, significantly decreased compared to pre-treatment (P<0.01). At last visit, there were 19 eyes with stable VA, 4 with VA improvement, 12 with diminished VA and 3 with complete loss light perception. There were 7 cases that failed during 3-year fellow up period. Cumulative probabilities of valve survival by Kaplan-Meier analysis were 82.9%, 74.1% and 71.0% at 12, 24 and 36mo, respectively. Cox stepwise regression analysis found that the survival time was significant associated with the pre-visual acuity <2/400 (P<0.05). Post-operative complications occurred in 8 eyes, of which hyphema presented in 2 eyes, choroidal effusion in 2 eyes.

CONCLUSION

The procedure of preoperative IVB and AGV implantation should be one of treatments for NVG because of its safety and effectiveness.

Glaucoma Drainage Device Coated with Mitomycin C Loaded Opal Shale Microparticles to Inhibit Bleb Fibrosis

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.

Subconjunctival Injections of Mitomycin C Are Associated with a Lower Incidence of Hypertensive Phase in Eyes with Ahmed Glaucoma Valve

PURPOSE

To evaluate the association of intraoperative and postoperative subconjunctival injections of mitomycin C (MMC) and rate of the hypertensive phase after implantation of the Ahmed glaucoma valve (AGV).

DESIGN

Comparative case series.

PARTICIPANTS

This retrospective comparative study included 37 eyes of 35 patients with uncontrolled glaucoma on maximum tolerated medical therapy who underwent implantation of AGV by a single surgeon.

METHODS

Consecutive cases operated without the use of MMC from 2015 to 2017 were compared with consecutive cases operated from 2018 to 2019 under a standardized protocol of subconjunctival MMC injections. The MMC group received 0.1 ml of MMC (0.25 mg/ml) injected intraoperatively, at 1 and 4 weeks after the surgery.

MAIN OUTCOME MEASURES

Incidence of the hypertensive phase (defined as intraocular pressure [IOP] >21 mmHg during the first 3 postoperative months) was compared across groups. Intraocular pressure and glaucoma medications were also compared during the course of the first 6 postoperative months.

RESULTS

In the MMC and no-MMC groups, 17.6% (3/17) and 55.0% (11/20) of the cases exhibited a hypertensive phase (P = 0.04), respectively. Both groups were comparable in baseline characteristics, including age, preoperative IOP, preoperative glaucoma medications, and previous glaucoma surgeries. At 6 months, mean IOP was 14.0 ± 0.8 mmHg and 14.7 ± 0.9 mmHg for the MMC and no-MMC groups, respectively (P = 0.6). The mean number of glaucoma medications at 6 months was 1.2 ± 0.2 and 2.2 ± 0.3 in the MMC and no-MMC groups, respectively (P = 0.007).

CONCLUSIONS

Eyes that underwent implantation of AGV experienced a lower incidence of hypertensive phase and required fewer medications when using a standardized protocol of intraoperative and postoperative subconjunctival MMC injections.

Safety and efficacy of Ahmed glaucoma valve implantation in refractory glaucomas in Northern Indian eyes

PURPOSE

To evaluate the safety and efficacy of Ahmed glaucoma valve (AGV) implantation in refractory glaucoma in Northern Indian eyes.

BACKGROUND

The success rate of trabeculectomy remains low in cases of refractory glaucoma even with the use of antifibrotics. Glaucoma drainage devices have proven to be more efficacious in reducing intraocular pressure (IOP) in these glaucomas.

METHODS

Retrospective records of 55 consecutive patients who underwent AGV implantation at Dr. Shroff's Charity Eye Hospital, New Delhi, India from January 2003 to December 2012 were reviewed. Pre-operative data included age, gender, eye laterality, specific diagnosis, number of anti-glaucoma medications, number of prior incisional surgeries, visual acuity and IOP on medical treatment. Postoperative data included visual acuity and IOP on day one, 1 week, 1 month, 3 months, 6 months, 1 year and yearly thereafter, number of anti-glaucoma medications, any complication or additional surgical intervention required. Success was defined as IOP >5 and <22 mmHg with or without treatment.

RESULTS

Mean IOP decreased from 39.71 ± 8.99 pre-operatively to 17.52 ± 5.72 mmHg at last follow-up (p < 0.001) and number of medications reduced from 3.27 ± 0.84 to 1.25 ± 0.88 (p < 0.001). Visual acuity remained within one Snellen line or improved at last follow-up in 47 cases (85.4%). The cumulative probability of success was 85.45% at 1 year and 79.63% at 3 years. The incidence of post-operative complications was 25.45%.

CONCLUSION

AGV implantation has proven to be safe and is effective in controlling IOP in refractory glaucoma in Northern Indian eyes.

Glaucoma drainage device implantation with adjunctive intravitreal bevacizumab in neovascular glaucoma: 3-year experience

Purpose

To evaluate the outcome of glaucoma drainage device (GDD) implantation with and without intravitreal bevacizumab (IVB) injection in treating neovascular glaucoma (NVG) at Cipto Mangunkusumo Hospital Jakarta, Indonesia.

Patients and methods

This retrospective study involved 39 eyes with NVG which underwent GDD implantation between 2012 and 2014. Thirty eyes underwent GDD implantation alone (control group) while 9 eyes underwent GDD implantation and IVB injection (IVB group). Visual acuity (VA), intraocular pressure (IOP), number of antiglaucoma medications, and success rate were compared between groups.

Results

There were no significant differences in preoperative characteristics. On the last visit, VA was 2.6 (0.2–4.0) logMAR in the control group and 2.3 (0.4–4.0) logMAR in the IVB group (P=0.97). In the control group, final VA was significantly worse compared to initial VA (P<0.01), while in IVB group VA was apparently stable (P=0.24). Final IOP was 16.3±10.3 mmHg in the control group and 12.0 (2.0–49.0) mmHg in IVB group (P=0.40). The number of antiglaucoma medications was similar between groups (P=0.57). Surgical success rate in the IVB group (66.7%) was better than the control group (56.7%), but this difference was not statistically significant (P=0.71). Kaplan–Meier survival analysis showed the probability of success 37 months after surgery as 53.6% in the IVB group and 31.6% in the control group. No significant difference was found between the groups (P=0.45).

Conclusion

In cases of NVG, GDD combined with IVB could maintain VA compared to GDD alone. However, there were no significant differences in final IOP, number of antiglaucoma medications, and surgical success rate.

Intraocular Pressure Control after Implantation of an Ahmed Glaucoma Valve in Eyes with a Failed Trabeculectomy

AIM

To evaluate the results of Ahmed glaucoma valve (AGV) in eyes with a failed trabeculectomy.

MATERIALS AND METHODS

This retrospective study evaluated 61 eyes with a failed trabeculectomy that underwent implantation of an AGV due to uncontrolled intraocular pressure (IOP) on maximal medical therapy. Success was defined as IOP ≤ 21 mm Hg (criterion 1) or 20% reduction in IOP (criterion 2) with or without antiglaucoma medications. Persistent hypotony, loss of light perception, and reoperation for IOP control were defined as failure.

RESULTS

Mean preoperative IOP and mean lOPs at 6, 12, and 24 months were 21.93 ± 6.32 mm Hg (n = 61), 14.15 ± 4.33 mm Hg (n = 59), 13.21 ± 4.44 mm Hg (n = 56), and 13.60 ± 3.27 mm Hg (n = 25) respectively. Mean number of antiglaucoma medications preoperatively and at 6, 12, and 24 months was 3.95 ± 0.85, 2.19 ± 1.38, 2.48 ± 1.44, and 2.40 ± 1.32 respectively. The reductions in the number of medications and IOP measurements were statistically significant at all time intervals (p < 0.001, Wilcoxon signed rank test). According to criterion 1, the Kaplan-Meier survival curve disclosed success rates of 75% at 12 and 24 months. According to criterion 2, the success rates were 57% at 12 months and 55% at 24 months. The most frequent complications were hypertensive phase (18%) and shallow anterior chamber (16.4%).

CONCLUSION

The AGV may effectively reduce IOP in eyes that had a failed trabeculectomy.

CLINICAL SIGNIFICANCE

The AGV is an alternative in eyes with a failed trabeculectomy.

HOW TO CITE THIS ARTICLE

Schimiti RB, Abe RY, Tavares CM, Vasconcellos JPC, Costa VP. Intraocular Pressure Control after Implantation of an Ahmed Glaucoma Valve in Eyes with a Failed Trabeculectomy. J Curr Glaucoma Pract 2016;10(3):97-103.

A novel surgical technique for prevention of Ahmed glaucoma valve tube exposure: long scleral flap augmented with Tenon advancement and duplication

Background

To describe a new technique and present its long-term outcome for prevention of Ahmed glaucoma valve (AGV) tube exposure in patients with refractory glaucoma.

Methods

Twenty-seven eyes of 24 patients (mean age, 50 years; age range, 16–78 years; 8 females, 16 males) with refractory glaucoma who had the AGV implant were retrospectively reviewed. For AGV implantation, a long scleral flap combined with Tenon advancement and duplication was used. In this technique, a long scleral flap is created to completely cover the extraocular part of valve’s tube, and the flap surface is covered with duplicated Tenon’s tissue. The average follow-up after AGV implantation was 21.7 months (range, 12–36 months).

Results

The mean intraocular pressure before the operation, which was 44.1 mmHg (range, 26–62 mmHg), decreased to 14.2 mmHg (range, 8–20 mmHg) at the last follow-up visit, showing 67% reduction with AGV implantation. The mean number of antiglaucomatous medications was 4.1 before the AGV implantation and decreased to 0.9 after the operation, showing 88% reduction. In 14 eyes (51.9%), there was no change in the best corrected visual acuity (BCVA), and in 11 eyes (40.7%), the BCVA increased by 2 lines on the Snellen chart postoperatively. No patient developed postoperative hypotony, flat anterior chamber, diplopia, strabismus, erosion or exposure of the tube, or tube/plate migration.

Conclusions

The long scleral flap augmented with Tenon advancement and duplication is an effective and safe surgical technique for the implantation of AGV and preventing tube exposure in cases of refractory glaucoma.

Surgical outcomes associated with a sutureless drainage valve implantation procedure in patients with refractory glaucoma

Purpose

To evaluate the safety and efficacy profile of a sutureless procedure for drainage valve implantation with combined cataract removal and/or endoscopic cyclophotocoagulation (ECP).

Materials and methods

A retrospective case series study of consecutive surgeries for Ahmed glaucoma valve (AGV; New World Medical) implantation in a 1-year period was analyzed. The surgery was performed using a Tisseel fibrin sealant (Baxter Healthcare Corporation) in place of sutures. Some subsets within the case series also included a cataract extraction with intraocular lens (CEIOL) insertion and/or ECP (Endo Optiks) within the same procedure. Primary outcomes for this study including efficacy (IOP change, reduction in medications) and safety (complications and reoperations) were measured out to 3 years. Comparisons between subsets were made using ANOVA with post hoc Tukey’s pairwise tests.

Results

One hundred twenty-two eyes of 99 patients underwent sutureless AGV implantation surgery. Of the 122, 18 had an AGV implantation only, 46 had an AGV + CEIOL, 35 had an AGV + ECP, and 23 had an AGV + CEIOL + ECP. In total, there was a significant decrease in IOP (P<0.0001) and number of glaucoma medications (P≤0.0054) at each postoperative visit. In a one-way ANOVA, there were no significant differences in mean IOP between the different subsets of surgeries (P>0.05); 10.7% and 14.8% of eyes required a reoperation either for a complication or for uncontrolled glaucoma, respectively.

Conclusion

Sutureless valve implantation is associated with a significant reduction in IOP percentage and medication use after the procedure with a safety profile comparable with other glaucoma surgeries.

Combined Ahmed valve and phacoemulsification with intraocular lens implantation under infliximab in refractory uveitic glaucoma

PURPOSE

To evaluate the outcome of combined Ahmed glaucoma valve (AGV) and phacoemulsification with posterior chamber intraocular lens implantation under infliximab in refractory uveitic glaucoma (UG).

METHODS

In this prospective interventional case series, 26 eyes of 26 patients with refractory UG underwent surgery under intravenous infliximab. The success rate was defined as intraocular pressure (IOP) 5 to 21 mm Hg with or without antiglaucoma medications (AGM), without additional glaucoma surgical intervention.

RESULTS

The mean IOP (37.8 ± 11.86 to 12.2 ± 2.8 mm Hg; p<0.0001) and mean number of AGM (3.4 ± 1.2 to 0.4 ± 0.1; p<0.001) were significantly reduced after surgery at 2 years. Kaplan-Meier survival analysis showed a cumulative probability of success for IOP control of 92% at 2 years of follow-up.

CONCLUSIONS

Combined AGV and phacoemulsification is an effective treatment for controlling refractory UG with complicated cataract under infliximab.