Table 3.
Summary of studies on combined or consecutive Ahmed glaucoma valve placement within the vitreous cavity and vitrectomy
| Author (Year of Publication) | Study design | Methodology | Results | Conclusions |
|---|---|---|---|---|
| Bernal-Morales et al. (2021) [ 16 ] | Retrospective case series | Maximum 2-year follow-up was performed for 51 eyes from 50 patients with severe NVG who were treated with PPV, AGV, and PRP and/or cryotherapy in a single surgical setting. Surgical success defined as IOP between 6 and 21 mmHg with or without topical medication. | Success rate for IOP control at 1, 6, 12, and 24 months postoperatively were 76.0%, 88.3%, 74.4%, and 71.4%, respectively. | Combined AGV implantation into the vitreous cavity and PPV in a single setting may be reasonable for severe forms of NVG for effective IOP control and complete PRP. |
| de Frutos-Lezaun et al. (2018) [ 17 ] | Retrospective case series | Maximum 1-year follow-up was performed for 10 eyes from 9 patients with secondary glaucoma, refractory to other treatments, who underwent 23-gauge PPV and AGV implantation in the vitreous base. | Absolute success, IOP < 21 mmHg without medication, was 60%. Qualified success, IOP < 21 mmHg with medication, was 100%. A significant decrease in postoperative IOP in all cases was recorded. No significant changes in postoperative BCVA compared to preoperative values were seen. Early complications were hyphema, athalamia, and retinal detachment, and late complications were cystic bleb and PP clip extrusion. | PP AGV implantation is a safe and useful treatment modality to manage secondary refractory glaucoma if the patient is a candidate for PPV or has undergone vitrectomy. |
| El-Saied et al. (2017) [ 19 ] | Case series | Maximum 6-month follow-up was performed for five patients with traumatic secondary glaucoma and vitrectomized, aphakic, and aniridic eyes who underwent AGV implantation into the vitreous cavity and complete filling of the vitreous cavity with non-expansile C3F8 for approximately 2 months after vitrectomy to treat VH. | Although multiple risk factors, such as aphakia, vitrectomized eyes, and aniridia, were presented, no postoperative hypotony or SCH was recorded. The C3F8 was absorbed over 2 months and mean postoperative IOP was 14.8 mmHg at 6 months. The final postoperative BCVA was 0.66 ± 0.13. | Complete filling of the vitreous cavity with non-expansile C3F8 gas prevented SCH following AGV implantation in the vitreous cavity in management of secondary glaucoma in vitrectomized, aphakic, and aniridic eyes. |
| García-Delpech et al. (2013) [ 20 ] | Case series | Maximum 28-month follow-up was performed for 17 eyes from 17 patients with refractory glaucoma who underwent AGV scleral suture-less implantation via PP using cyanoacrylate suturing of the plate. Refractory glaucoma defined as IOP ≥ 21 mm Hg with anti-glaucoma agents, good adherence to treatment, and no history of glaucoma surgery. | IOP control, defined as IOP ≤ 21 mmHg with or without anti-glaucoma agents, was achieved in 82.2% of patients. Of all patients, 58.8% did not require IOP-lowering medications. Postoperative complications were transient IOP rise, transient hyphema, early hypotony, and tube block by the vitreous, and both resolved with the second intervention. No case of AGV tube or plate extrusion, plate migration, choroidal or retinal detachment, or VH was reported. | AGV implantation into the vitreous cavity with cyanoacrylate was a safe and effective treatment for refractory glaucoma. |
| Wallsh et al. (2013) [ 18 ] | Case series | Maximum 28-month follow-up was performed for 31 eyes with glaucoma associated with posterior-segment disease who underwent combined PPV and AGV implantation. | In 24 eyes with NVG, IOP decreased from 37.6 to 13.8 mmHg, and BCVA improved from 2.13 to 1.40 logMAR. In 15 eyes with steroid-induced glaucoma, IOP deceased from 27.9 to 14.1 mmHg, and BCVA improved from 1.38 to 1.13 logMAR. Complications included four cases of cystic bleb formation and one case of choroidal detachment and explantation for hypotony. | Combined AGV implantation via the PP and vitrectomy is an effective treatment in complex cases of glaucoma without using the PP clip. |
| Jeong et al. (2012) [ 21 ] | Retrospective case series | Maximum 25-month follow-up was performed for 11 patients with PDR and refractory NVG who underwent combined 23-gauge sutureless PPV with PP AGV implantation. | The mean preoperative IOP reduced from 35.9 ± 6.3 to 13.3 ± 3.2 mmHg at the last postoperative follow-up. IOP control was achieved in all patients, 91% of whom required anti-glaucoma agents with a mean number of medications of 1.2 ± 0.6. The postoperative visual acuity improved from 1.67 ± 0.61 to 0.96 ± 0.67 logMAR. No unmanageable complications were reported. | Combined 23-gauge PPV and AGV implantation was safe and effective in patients with PDR and refractory NVG. |
| Milla et al. (2012) [ 22 ] | Case report | A 41-year-old woman had bilateral lens subluxation, medically uncontrolled glaucoma, and Marfan syndrome confirmed by complete systemic examination and genetic analysis of the fibrillin 1 gene. | To control severe glaucoma in the right eye, the patient underwent PPV with lensectomy and AGV implantation in the vitreous cavity. | Aggressive secondary glaucoma after Marfan syndrome with lens subluxation requires surgical management with lensectomy, PPV, and AGV implantation to avoid progressive glaucomatous optic atrophy. |
| Diaz-Llopis et al. (2010) [ 23 ] | Prospective case series | The PP clip in the AGV tube was inserted via the PP combined with PPV in 10 patients with secondary refractory glaucoma. | IOP control was achieved in 90% of patients, and no anti-glaucoma medication was required in 70% of patients. The complications were transient hypotony in three cases, choroidal detachment in two cases, and intraocular hemorrhage in one case. No tube extrusion or tube kink was found. | Combined implantation of the AGV tube modified with the PP clip via the PP with PPV was safe and effective in management of secondary refractory glaucoma. |
| Dada et al. (2010) [ 30 ] | Case series | Maximum 12-month follow-up was performed for 11 eyes with uncontrolled IOP on maximum tolerable anti-glaucoma medication who underwent AGV implantation with triamcinolone-assisted PPV. | The mean preoperative IOP of 33.64 ± 5.99 reduced to 17.09 ± 2.26 and 17.45 ± 1.81 mmHg at the 6- and 12- month postoperative follow-ups. The mean number of anti-glaucoma agents reduced from 3.27 ± 0.05 to 0.64 ± 0.67 and 0.55 ± 0.6 at the 6- and 12-month postoperative follow-ups. | Combined PP AGV implantation and triamcinolone-assisted vitrectomy was a suitable treatment modality to manage refractory glaucoma with aphakia, particularly in eyes with endothelial cell decompensation. |
| Adachi et al. (2008) [ 31 ] | Case series | Maximum 12-month follow-up was performed for five eyes with refractory glaucoma that underwent PPV and posterior-chamber AGV implantation. | The mean IOP reduced from 46.8 ± 15.7 mmHg preoperatively to 16.0 ± 2.0 mmHg postoperatively. The visual acuity improved in three eyes or 60% of patients and reduced in two eyes: one due to retinal detachment and another due to transient high IOP and VH. IOP control was achieved in 80% of patients. | AGV implantation in the posterior chamber for refractory glaucoma was effective. |
| Faghihi et al. (2007) [ 24 ] | Case series | Maximum 28-month follow-up was performed for 18 eyes from 17 patients with NVG who underwent PPV with PP AGV implantation. | The mean preoperative IOP with an oral and two or three topical anti-glaucoma agents reduced from 53.3 ± 10 to 16.3 ±7.1 mmHg without oral anti-glaucoma agents at the final visit. The success rate, defined as IOP of 5–21 mmHg with or without anti-glaucoma agents, was 72.2%. Seven (38.8%) patients experienced a postoperative hypertensive phase, and all but one patient was managed with medication. Visual acuity improvement or stabilization was recorded in 77.7% of eyes. Postoperative complications ranged from mild VH to corneal ulceration. Two eyes developed phthisis bulbi. | Combined PPV and AGV implantation was a suitable and safe treatment modality to manage NVG with preexisting posterior-segment pathology. |
| Schlote et al. (2006) [ 25 ] | Case series | Maximum 18-month follow-up was performed for 11 eyes of 9 patients with aphakic, neovascular, traumatic, inflammatory and pseudoexfoliation glaucoma who had PPV before AGV implantation. | IOP ≤ 21 mmHg was achieved in 91% of eyes. Of all patients, 64% required no anti-glaucoma agents. The mean preoperative IOP decreased significantly from 32.2 ± 8.3 to 15.7 ± 7.7 mmHg postoperatively. The mean number of topical anti-glaucoma agents decreased significantly from 2.9 ± 1.2 to 0.545 ± 0.78. Complications included transient hypotony, transient choroidal effusion, and an intermediate increase in IOP. One eye had tube exchange, and two eyes required needling/bleb excision. | PP-modified AGV implantation was effective and safe in vitrectomized eyes with advanced glaucoma. Close follow-up and IOP monitoring were required for 1 year. |
Abbreviations: NVG, neovascular glaucoma; PPV, pars plana vitrectomy; AGV, Ahmed glaucoma valve; PRP, pan-retinal photocoagulation; IOP, intraocular pressure; mmHg, millimeter of mercury; BCVA, best-corrected visual acuity; PP, pars plana; C3F8, perfluoropropane; VH, vitreous hemorrhage; SCH, Suprachoroidal hemorrhage; logMAR, the logarithm of the minimum angle of resolution.