Trabeculectomy for neovascular glaucoma in proliferative diabetic retinopathy, central retinal vein occlusion, and ocular ischemic syndrome: Surgical outcomes and prognostic factors for failure

Demographic, Socioeconomic, and Clinical Factors Associated with Severe Vision Loss in Patients with Neovascular Glaucoma

Purpose

To investigate the association between demographic, socioeconomic, and clinical factors and severe vision loss in patients with neovascular glaucoma (NVG).

Patients and Methods

A retrospective chart review of patients referred to the University of Virginia (UVA), diagnosed with NVG, and treated for NVG between January 2010 and December 2020 was performed. Patients were grouped according to vision outcomes after 1 year of treatment: mild - moderate vision loss (best corrected visual acuity [BCVA] > light perception [LP]) and severe vision loss (BCVA ≤ LP). The associations between patient characteristics and BCVA were also examined.

Results

Of the 89 patients (99 eyes), those with progression to severe vision loss presented with higher intraocular pressure (IOP) (p < 0.001) and lower visual acuity (p = 0.003) on average. However, there was no difference in IOP between the vision loss groups after one year of treatment. Univariate analysis showed a moderate association between a history of type 2 diabetes mellitus (T2DM) and severe vision loss (p = 0.033). Increasing age was associated with an increased likelihood of progression to severe vision loss (odds ratio [OR] 1.074, p = 0.008). Females were more likely to exhibit severe vision loss (OR 3.281, p = 0.036). Patients with Medicare (OR 0.098, p = 0.005) or private insurance (OR 0.110, p = 0.006) were less likely to progress to severe vision loss than those without insurance.

Conclusion

Progression of vision loss in patients with NVG may be influenced by the stage of disease at diagnosis, age, sex, T2DM, and insurance status.

Long-term results of Ahmed glaucoma valve implantation with/without intravitreal anti-VEGF injection in neovascular glaucoma patients

PURPOSE

This study aimed to evaluate the efficacy of Ahmed glaucoma valve (AGV) implantation with or without anti-VEGF injections in neovascular glaucoma patients.

MATERIALS AND METHODS

This single-center retrospective study assessed NVG patients who underwent AGV implantation with or without anti-VEGF injections. Demographic and clinical data, including ocular findings, intraocular pressure (IOP), visual acuity, and glaucoma medication count, were recorded preoperatively and postoperatively at one day, one month, and one year. The study included 35 patients. Group 1 consisted of 23 patients who received anti-VEGF injections before AGV surgery. Group 2, with 12 patients, had no anti-VEGF injections prior to surgery. Successful surgery was defined as IOP values between 6 and 21mmHg. The primary outcome was a 30% or more reduction in IOP.

RESULTS

The groups displayed no significant difference in their demographic or clinical profiles (P>0.05). The visual acuity before and one year after surgery did not differ significantly between the groups. However, IOP values significantly decreased by the end of the one-year follow-up for both groups. No significant differences were found between the groups regarding visual acuity, IOP, or the number of medications during the one-year follow-up (P>0.05). Success rates were 95.7% for Group 1 and 91.7% for Group 2. No significant difference in complications between the groups was observed (P>0.05).

CONCLUSION

Anti-VEGF injections prior to AGV implantation did not significantly impact visual acuity, IOP values, or medication count during the one-year follow-up.

Factors Affecting the Results of Ahmed Glaucoma Valve Implantation in Diabetic Neovascular Glaucoma With or Without Previous Pars Plana Vitrectomy

Objectives

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.

Methods

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.

Results

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).

Conclusion

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.

[Current views on pathogenesis and treatment of neovascular glaucoma]

Neovascular glaucoma is a type of secondary glaucoma characterized by the most severe course, and ranking second among the causes of irreversible blindness. This review summarizes the results of numerous studies devoted to the search for prevention measures and the most effective treatment strategy. The main ways of preventing the development of neovascular glaucoma are timely diagnosis and elimination of ischemic processes in the retina, combined with adequate control of intraocular pressure and treatment of the underlying disease.

The mechanism and therapeutic strategies for neovascular glaucoma secondary to diabetic retinopathy

Neovascular glaucoma (NVG) is a devastating secondary glaucoma characterized by the appearance of neovascular over the iris and the proliferation of fibrovascular tissue in the anterior chamber angle. Proliferative diabetic retinopathy (PDR) is one of the leading causes of NVG. Currently increasing diabetes population drive the prevalence rate of NVG into a fast-rising lane. The pathogenesis underlying NVG makes it refractory to routine management for other types of glaucoma in clinical practice. The combination of panretinal photocoagulation (PRP), anti-vascular endothelial growth factor (VEGF) injections, anti-glaucoma drugs, surgical intervention as well as blood glucose control is needed. Early diagnosis and aggressive treatment in time are crucial in halting the neovascularization process and preserving vision. This review provides an overview of NVG secondary to diabetic retinopathy (DR), including the epidemiology, pathogenesis and management, so as to provide a better understanding as well as potential therapeutic strategies for future treatment.

Downregulation of angiogenic factors in aqueous humor associated with less intraoperative bleeding in PDR patients with NVG receiving conbercept: a randomized controlled trial

BACKGROUND

To analyze the level changes of 28 cytokines in aqueous humor of patients with proliferative diabetic retinopathy (PDR) coexisting neovascular glaucoma (NVG) after intravitreal injection of conbercept (IVC), and to investigate whether these cytokines are associated with intraoperative bleeding (IOB).

METHODS

Totally 34 eyes with NVG secondary to PDR were enrolled. Patients were randomized into two groups, and all of them underwent 25-gauge pars plana vitrectomy (PPV) combined with trabeculectomy. Group I, 18 eyes received IVC 3 days before PPV, and 100 µL aqueous humor was collected at the time of IVC pretreatment and 3 days later at the beginning of PPV respectively. Group II, 16 eyes received IVC after PPV, and 100 µL aqueous humor was collected only at the beginning of PPV. Aqueous humor from 19 eyes with age-matched cataract patients served as controls. Luminex bead-based multiplex array was used to measure the levels of 28 cytokines in aqueous humor. The baseline cytokine levels were compared among the three groups. All NVG patients were divided into IOB and non-bleeding (INB) groups. The cytokine levels of aqueous humor at the beginning of PPV were compared between group I and II, also between IOB and INB groups. IOB in NVG patients was graded according to vitreous bleeding amount. The correlation between cytokine levels and the grades of IOB were analyzed.

RESULTS

Compared with controls, the baseline levels of 18 cytokines associated with inflammation and angiogenesis showed significantly increased in group I and group II (all, P < 0.0167). The IOB rate as well as the levels of IL-4, IL-22, Ang-2, PLGF and VEGF-A in group I were significantly lower than in group II (all, P < 0.05). The levels of IL-4, IL-22, Ang-2, PLGF and VEGF-A were significantly lower in INB group than in IOB group (all, P < 0.05). The levels of IL-4, Ang-2, PLGF and VEGF-A were positively correlated with the grades of IOB in NVG patients (all, r_s > 0.4, P < 0.05).

CONCLUSIONS

IVC 3 days before PPV combined with trabeculectomy reduces IOB in NVG patients, in which the downregulation of IL-4, Ang-2, PLGF and VEGF-A after IVC may be an underlying mechanism.

TRIAL REGISTRATION

ChiCTR2100048118 , retrospectively registered on 2 July 2021.