Comparative study of the outcomes of newly developed polypropylene-based modified trabeculectomy and glaucoma shunt surgery in neovascular glaucoma

BACKGROUND

Neovascular glaucoma (NVG) is a secondary glaucoma with a poor visual prognosis. Trabeculectomy with antifibrotic agents, glaucoma drainage devices (GDDs), and cyclo-destructive procedures are recommended in patients who are refractory to medical management. However, due to the poor success rate of conventional trabeculectomy and the higher cost of GDDs, alternative procedures need to be looked at.

PURPOSE

To compare the surgical outcomes and economic aspects of a newly developed polypropylene suture bed-based modified trabeculectomy to Ahmed glaucoma valve (AGV) implantation for NVG.

METHODS

It was a prospective interventional study conducted at a tertiary care center between 2018 and 2020. Consecutive patients with NVG with a minimum follow-up of 18 months were included. Surgical outcomes are mainly based on intraocular pressure (IOP) control and the cost of surgery.

RESULTS

Sixty eyes were included out of which 40 (60.6%) underwent modified trabeculectomy and 20 (33.7%) underwent AGV. At the final follow-up, no significant difference (P < 0.05) was found between the surgical outcomes of both groups. The complete success rate (IOP < 21 mm Hg without antiglaucoma medications) was 60 and 65% while the qualified success rate (IOP < 21 mm Hg with antiglaucoma medications) was 30 and 25% in modified trabeculectomy and AGV groups, respectively, at final follow-up. The cost of surgery was significantly higher in the AGV group (P < 0.0001).

CONCLUSION

Modified trabeculectomy as described might be a better alternative for NVG eyes.

Long-Term Outcomes of Ahmed Glaucoma Valve Surgery in a Scottish Cohort of Patients With Refractory Glaucoma

Purpose The purpose of this study was to evaluate the long-term efficacy and safety profile of the Ahmed glaucoma valve (AGV) implantation in cases of refractory glaucoma. Methods We conducted a retrospective audit of patients that underwent AGV implantation between 2006 and 2017 by two glaucoma surgeons in a tertiary glaucoma centre (Glasgow, UK). Primary outcome measures included the post-operative intraocular pressure (IOP), number of glaucoma medications, best-corrected visual acuity, complications, re-operation rates, and failure (defined as IOP > 21 mmHg or not reduced by 20% from baseline, IOP ≤ 5 mmHg, reoperation for glaucoma, removal of implant, or loss of light perception) at pre-defined time points (years 1 to 8). Results A total of 111 eyes of 94 patients were identified with a mean follow-up of 48.5 months (SD: 31.5); 60.3% of eyes had undergone at least one previous glaucoma surgery. Mean presenting IOP was 31.7 mmHg (SD: 11.4), and it reduced to 13.9 mmHg (SD: 4.2) in year 5 and 16.3 mmHg in year 8 (p<0.05). The number of glaucoma medications reduced from 3.8 (SD: 1.4) to 2.4 (SD: 1.4) and 2.6 (SD: 1.4) in the above time points (p<0.05 except year 8). The five-year success rate was 65.2%, and the five-year reoperation rate was 37% excluding cataract surgery. The most common early complications were hyphaema (12.6%) and transient hypotony (8.1%), whereas the most common late complication was an encapsulated bleb (15.1%). Conclusions AGV implantation is an effective procedure for controlling IOP in the long term in cases of refractory glaucoma.

A New Technique Using a 4-0 Nylon Thread as a Guide for Easy and Precise Tube Insertion of Ahmed Glaucoma Valve Implant Into Ciliary Sulcus

We present a new technique for inserting the tube of the Ahmed glaucoma valve (AGV) (model FP7; Rancho Cucamonga, CA: New World Medical) implant into the ciliary sulcus, easily and precisely, using a 4-0 nylon thread as a guide. An 88-year-old woman received AGV implantation for secondary angle recession glaucoma with underlying pseudoexfoliation syndrome in her left eye. She had a history of trauma with mild intraocular lens (IOL) oscillation and poor mydriasis, with maximum pupil diameter of 3.5 mm. Ciliary sulcus tube insertion in such patients sometimes becomes difficult, however, using a 4-0 nylon thread as a guide, precise insertion was achieved easily in the following way. A 4-0 nylon thread was placed into the anterior chamber through a 1 mm incision opposite the site of the AGV implant. Subsequently, a 23G needle was inserted into the sclera 2 mm from the corneal limbus in the same quadrant as AGV implants. The tip of the 23G needle proceeded horizontally to the iris, through the sclera and ciliary body, and into the ciliary sulcus. At the center of the pupil, the 4-0 nylon thread was introduced into the lumen of the 23G needle. Subsequently, the 23G needle, together with the 4-0 nylon thread in the lumen was withdrawn out of the eye. The 4-0 nylon was then inserted into the tube lumen of the AGV implant. Finally, by using 4-0 nylon as a guide, the Ahmed tube was inserted into the ciliary sulcus precisely without much difficulty.

'Progressive peripheral anterior synechiae in iridocorneoendothelial syndrome- a crawling disaster'

PURPOSE

Iridocorneal endothelial (ICE) syndrome is well known to cause refractory glaucoma in young adults. Commonly acclaimed mechanism for trabeculectomy failure in these cases include accelerated subconjunctival fibrosis, abnormal endothelial proliferation, and closure of ostium. In the following article, we present a case of Iridocorneal endothelial syndrome that presented with refractory glaucoma after trabeculectomy due to rapidly progressive peripheral anterior synechiae causing angle closure and corneal decompensation that mandated a tailored surgical approach of management. Methods: This is a descriptive case report based on electronic medical records, patient observation, surgical intervention, and follow-ups. Case description: A thirty-eight-year-old-male presented to us with signs suggestive of iridocorneal endothelial syndrome with gonioscopy revealing peripheral anterior synechiae (PAS) over four clock-hours temporally. Uncontrolled intraocular pressure (IOP) despite maximal medical therapy mandated augmented trabeculectomy with anti-fibrotics. The bleb failed within 3 weeks of trabeculectomy, with evidence of progressive crawling PAS causing endothelial decompensation and raised IOP. He underwent Ahmed glaucoma valve (AGV) implant surgery with viscosynechiolysis and sectoral iridectomy under antiviral cover. This helped control IOP and retain corneal clarity, with no recurrence of PAS in the affected area. Conclusion: Progressive peripheral synechiae in ICE syndrome can cause early bleb failure and refractory glaucoma. Careful viscosynechiolysis and sectoral iridectomy alongside a second implant surgery can help salvage visual functions and preserve corneal clarity while preventing further progression of PAS in these eyes.

Effect of anti-vascular endothelial growth factor on the surgical outcome of neovascular glaucoma: An overview and meta-analysis

BACKGROUND

Bevacizumab is known to be very effective in inhibiting ocular neovascularization in neovascular glaucoma (NVG). The purpose of this study is to evaluate the effect of anti-vascular endothelial growth factor on the surgical outcome of Ahmed glaucoma valve implantation (AGVI) in NVG.

METHODS

An extensive search of PubMed, EMBASE, and the Cochrane Library was carried out in January 2021 to select relevant studies. The weighted mean difference of the intraocular pressure reduction percentage from baseline to endpoint was used for the primary efficacy estimate. Mantel-Haenszel odds ratios and 95% confidence intervals (CIs) for success rate were employed as secondary efficacy estimates. The number of postoperative interventions and the tolerability estimate for adverse events were also measured using odds ratios. We conducted meta-analyses of fixed effects models using comprehensive meta-analysis software to pool the results of the included studies. Heterogeneity was assessed using Q-value and I2 measures.

RESULTS

Nine studies were included in the analysis, encompassing a total of 410 eyes. There was no significant difference in intraocular pressure reduction percentage between the AGVI-only group and the AGVI with adjuvant bevacizumab group (estimate 0.324; 95% CI, -0.278-0.926; P = .244). However, the success rate favored the AGVI with adjuvant bevacizumab group (estimate 0.561; 95% CI, 0.097-1.025, P = .018).

CONCLUSIONS

AGVI with adjuvant bevacizumab had no significant effect on lowering IOP in patients with neovascular glaucoma compared with AGVI alone. However, the final success rate was higher for AGVI with adjuvant bevacizumab treatment than with AGVI alone.

Clinical efficacy analysis of Ahmed glaucoma valve implantation in neovascular glaucoma and influencing factors: A STROBE-compliant article

This study aimed to evaluate the efficacy of Ahmed glaucoma valve (AGV) implantation in treating neovascular glaucoma (NVG) and to analyze the factors influencing the surgical success rate.This is a retrospective review of 40 eyes of 40 NVG patients who underwent AGV implantation at Xiangya Hospital of Central South University, China, between January 2014 and December 2016. Pre- and postoperative intraocular pressure (IOP), visual acuity, surgical success rate, medications, and complications were observed. Surgical success criteria were defined as IOP ≤21 and >6 mm Hg with or without additional medications. Kaplan-Meier survival curves and Multivariate cox regression analysis were used to examine success rates and risk factors for surgical outcomes.The mean follow-up period was 8.88 ± 3.12 months (range: 3-17). IOP declined at each visit postoperatively and it was statistically significant (P < .001). An average of 3.55 ± 0.86 drugs was applied preoperatively, while an average of 0.64 ± 0.90 drugs was used postoperatively, with the difference being of statistical significance (P < .05). The complete surgical success rate of 3, 6, and 12 months after the operation was 85%, 75%, and 65%, respectively. Meanwhile, the qualified success rate of 3, 6, and 12 months after the operation was 85%, 80%, and 77.5%, respectively. The multivariate cox regression analysis showed that age (hazard ratio: 3.717, 7.246; 95% confidence interval: 1.149-12.048, 1.349-38.461; P = .028, .021) was influencing factors for complete success rate and qualified success rate among all NVG patients. Gender, previous operation history, primary disease, and preoperative IOP were found to be not significant.AGV implantation is an effective and safe surgical method to treat NVG. Age is an important factor influencing the surgical success rate.

Efficacy of intravitreal ranibizumab combined with Ahmed glaucoma valve implantation for the treatment of neovascular glaucoma

BACKGROUND

Neovascular glaucoma is a refractive glaucoma. Recently, anti-VEGF factors have been used alone or in combination for the treatment of neovascular glaucoma. However, the medium- and long-term efficacy of such drugs remains to be evaluated. This study was to determine the efficacy of intravitreal ranibizumab combined with Ahmed glaucoma valve implantation for the treatment of neovascular glaucoma.

METHODS

In this prospective non-randomized study, 43 neovascular glaucoma patients (43 eyes) were assigned to receive either 0.5 mg intravitreal ranibizumab for three to 14 days before Ahmed glaucoma valve implantation (injection group, n = 21) or Ahmed glaucoma valve implantation alone (control group, n = 22). The patients were followed up for six to 12 months. Differences in surgical success rate, intraocular pressure, best corrected visual acuity, anti-glaucoma medications and postoperative complications were compared between the two groups. Surgical success was defined as IOP > = 6 mm Hg and < = 21 mm Hg, with or without the use of anti-glaucoma medications, and without severe complications or reoperation.

RESULTS

Of the 43 patients, 40 completed the 6-month follow-up and 37 completed the 1-year follow-up. Success rate was 73.7% vs. 71.4% at six months and 72.2% vs. 68.4% at 12 months in the injection group and the control group respectively. No significant difference was noted between the two groups (six months: P = 0.87, 12 months: P = 1.00). There were no significant differences in the two groups with respect to intraocular pressure, best corrected visual acuity, anti-glaucoma medications or postoperative complications at six months or 12 months.

CONCLUSIONS

Single intravitreal ranibizumab (0.5 mg) before surgery has no significant effect on the medium- or long-term outcomes of neovascular glaucoma treated with Ahmed glaucoma valve implantation.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ( ChiCTR-OOC-14005709, Trial registration date: 2014-12-01).