Risk Factors of Neovascular Glaucoma After 25-gauge Vitrectomy for Proliferative Diabetic Retinopathy with Vitreous Hemorrhage: A Retrospective Multicenter Study

Bilateral vitrectomy in patients with proliferative diabetic retinopathy-characteristics and surgical outcomes

PURPOSE

Comparing characteristics and outcomes of patients with bilateral proliferative diabetic retinopathy (PDR) undergoing concurrent and sequential vitrectomy.

METHODS

Patients having bilateral vitrectomy were classified into concurrent (requiring bilateral surgery simultaneously) and sequential (indicating vitrectomy in one eye later) groups. Clinical characteristics and outcomes were compared, and correlation between the first and second-operated eyes was analyzed.

RESULTS

One hundred eight and 126 eyes were in the concurrent and sequential groups, respectively. The sequential group was older (50 vs. 45 years, P = 0.017), had less retinal detachment (54 vs. 77%, P < 0.001), and better visual outcomes (0.79 vs. 1.30, P = 0.021), especially the second-operated eyes. The concurrent group had weaker correlations of disease severity (phi coefficient: 0.36 vs. 0.61) and post-operative visual acuity (r: 0.12 vs. 0.34) between the first- and second-operated eyes than the sequential group. Prior intravitreal injection of anti-vascular endothelial growth factor (odds ratio [OR] 0.37, 95% confidence interval [CI] 0.15-0.86, P = 0.025) predicted better outcomes, while post-operative neovascular glaucoma predicted worse outcomes (OR 6.5, 95% CI 1.7-27.9, P = 0.008).

CONCLUSIONS

PDR patients requiring surgery concurrently were younger and had more severe diseases and worse outcomes. However, poor outcomes in the first eye did not predict similar outcomes in the second eye.

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.

The role of artificial intelligence in analysis of biofluid markers for diagnosis and management of glaucoma: A systematic review

PURPOSE

This review focuses on utility of artificial intelligence (AI) in analysis of biofluid markers in glaucoma. We detail the accuracy and validity of AI in the exploration of biomarkers to provide insight into glaucoma pathogenesis.

METHODS

A comprehensive search was conducted across five electronic databases including Embase, Medline, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Web of Science. Studies pertaining to biofluid marker analysis using AI or bioinformatics in glaucoma were included. Identified studies were critically appraised and assessed for risk of bias using the Joanna Briggs Institute Critical Appraisal tools.

RESULTS

A total of 10,258 studies were screened and 39 studies met the inclusion criteria, including 23 cross-sectional studies (59%), nine prospective cohort studies (23%), six retrospective cohort studies (15%), and one case-control study (3%). Primary open angle glaucoma (POAG) was the most commonly studied subtype (55% of included studies). Twenty-four studies examined disease characteristics, 10 explored treatment decisions, and 5 provided diagnostic clarification. While studies examined at entire metabolomic or proteomic profiles to determine changes in POAG, there was heterogeneity in the data with over 175 unique, differentially expressed biomarkers reported. Discriminant analysis and artificial neural network predictive models displayed strong differentiating ability between glaucoma patients and controls, although these tools were untested in a clinical context.

CONCLUSION

The use of AI models could inform glaucoma diagnosis with high sensitivity and specificity. While insight into differentially expressed biomarkers is valuable in pathogenic exploration, no clear pathogenic mechanism in glaucoma has emerged.

Short-Term Postoperative Outcome of Baerveldt Glaucoma Implant with Two Tubes Inserted into the Vitreous Cavity

Here, we report a new surgical technique designed to increase filtration volume and reduce intraocular pressure (IOP) in glaucoma and its one-year outcome. Two tubes were created from a single Baerveldt glaucoma implant (BI) by folding the tube in a U-shape and incising only the outer edge of the stretched loop tip. The tubes were placed into the vitreous cavity via the pars plana through a long scleral tunnel, without a scleral valve or graft patch. Twenty eyes of 18 patients with neovascular glaucoma were included. This technique was performed in 10 eyes of 10 patients (double group), and outcomes were compared to 10 eyes of eight patients in which a single tube BI was inserted (single group). The primary outcome measures included IOP, supplemental medical therapy score (SMTS), and intraoperative and postoperative complications before and after surgery at 12 months. The mean IOP (SMTS) were 32.0 ± 11.33 mmHg (4.1) in the double group and 29.7 ± 6.31 mmHg (5.7) in the single group, preoperatively reduced to 11.8 ± 2.70 mmHg (0.2) (63% reduction, p < 0.004) and 14.2 ± 4.05 mmHg (1.1) (52% reduction, p < 0.002) after 12 months, respectively. SMTS showed 95% (p = 0.005) and 89% (p = 0.005) reductions, respectively. Although there was no significant difference in IOP between the two groups at 12 months (p = 0.16), there were significant differences in the SMTS between the two groups before, and 6 and 12 months after, surgery (p = 0.01, 0.04 and 0.04, respectively). A reduction in the SMTS suggests that increasing filtration volume by placing two tubes has the potential to further reduce IOP as compared with a single tube.

Ocular findings, surgery details and outcomes in proliferative diabetic retinopathy patients with chronic kidney disease

Purpose

We investigated the influence of impaired renal function on fundus characteristics, pars-plana vitrectomy (PPV) details, and outcomes in patients with proliferative diabetic retinopathy (PDR).

Design

A retrospective cohort study

Methods

We investigated a consecutive series of PDR patients who underwent PPV. The diabetic complications, previous photocoagulation, intravitreal injections before PPV, ocular findings during PPV, surgical details, short-term visual outcome and post-PPV complications were recorded and compared between patients with and without impaired renal function.

Results

149 patients had normal renal function (67.7%), and 71 (32.3%) patients had impaired renal function; 85.4% of patients were identified with chronic kidney disease (CKD) during the preoperative assessment. Impaired renal function was related to hypertension (3.40[1.58–7.29], p = 0.002), incomplete pan-retinal photocoagulation (PRP) (3.18[1.50–6.72], p = 0.002), severe fibrovascular membrane (8.19[3.43–19.54], p<0.001), and extensive retinal vascular closure (3.40[1.54–7.52], p = 0.002). There was a more frequent occurrence of severe intraoperative bleeding (56.3%, 32.2%, p = 0.001) and a higher percentage of intraocular subretinal fluid drainage (45.1%, 22.1%, p = 0.008) in patients with impaired renal function. The percentage of patients whose visual acuity (VA) increased was similar between the two groups (42.3%, 54.4%, p = 0.34).

Conclusions

In PDR patients, screening for CKD was required before PPV. PDR patients with impaired renal function tended to have more severe ischemic retinal conditions. Comparable PPV outcomes could be obtained in patients with and without impaired renal damage.

Inner limiting membrane peeling prevents secondary epiretinal membrane after vitrectomy for proliferative diabetic retinopathy

AIM

To evaluate the role of internal limiting membrane (ILM) peeling in preventing secondary epiretinal membrane (ERM) formation in pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR).

METHODS

This retrospective study analyzed the medical records of patients who underwent PPV for PDR and were followed up for minimum 3mo. ILM peeling was performed based on the intraoperative surgeons' judgments. ERM was assessed by optical coherence tomography photography. The relationship between ILM peeling and postoperative ERM was analyzed.

RESULTS

In total, 212 eyes from 197 patients were included in this study. The incidence of secondary ERM in the ILM non-peeling group was significantly higher than that in the ILM peeling group (37.0% vs 14.0%; P<0.001). Multivariate logistical regression revealed that ILM peeling was highly associated with the prevention of secondary ERM development [odds ratio 0.38; 95% confidence interval 0.17-0.86; P<0.05].

CONCLUSION

ILM peeling during PPV for PDRs can effectively reduce the incidence of secondary ERM development and is worth consideration by vitreoretinal surgeons.

A prediction model for worsening diabetic retinopathy after panretinal photocoagulation

BACKGROUND

As one of the severe complications of diabetes mellitus, diabetic retinopathy (DR) is the leading cause of blindness in the working age worldwide. Although panretinal photocoagulation (PRP) was standard treatment, PRP-treated DR still has a high risk of progression. Hence, this study aimed to assess the risk factors and establish a model for predicting worsening diabetic retinopathy (DR-worsening) within five years after PRP.

METHODS

Patients who were diagnosed with severe non-proliferative diabetic retinopathy or proliferative diabetic retinopathy and treated with PRP were included, and those patients were randomly assigned to either a training or validation cohort. The multivariate logistic regression analysis was used to screen potential risk factors for DR-worsening in the training cohort. Then the model was established after including significant independent risk factors and further validated using discrimination and calibration.

RESULTS

A total of 271 patients were included, and 56.46% of patients had an outcome of DR-worsening. In the training cohort (n = 135), age (odds ratio [OR] = 0.94, 95% confidence interval [CI] 0.90-0.98), baseline best corrected visual acuity (logMAR) (OR = 10.74, 95% CI 1.84-62.52), diabetic nephropathy (OR = 9.32, 95% CI 1.49-58.46), and hyperlipidemia (OR = 3.34, 95% CI 1.05-10.66) were screened out as the independent risk factors, which were incorporated into the predictive model. The area under the receiver operating characteristic curve and calibration slope in the training and validation cohort were 0.79, 0.96 (95% CI 0.60-1.31), and 0.79, 1.00 (95% CI 0.66-1.34), respectively. Two risk groups were developed depending on the best cut-off value of the predicted probability, and the actual probability was 34.90% and 82.79% in the low-risk and high-risk groups, respectively (P < 0.001).

CONCLUSIONS

This study developed and internally validated a new model to predict the probability of DR-worsening after PRP treatment within five years. The model can be used as a rapid risk assessment system for clinical prediction of DR-worsening and identify individuals at a high risk of DR-worsening at an early stage and prescribe additional treatment.

Prognostic Evaluation of Vitrectomy Assisted by Lucentis in Diabetic Retinopathy and Neovascular Glaucoma

For verifying the prognosis of Lucentis-assisted vitrectomy (PPV) in diabetic retinopathy (DR) and neovascular glaucoma (NVG), a retrospective analysis of DR and NVG patients who were admitted to our hospital from July 2019 to December 2020 was conducted. According to the treatment protocol, subjects who had PPV intervention were in the control group (CG; n = 38) and those receiving Lucentis adjunctive PPV were included in the intervention group (RG; n = 40). The indicators between groups were listed: treatment success rate, postoperative complication rate, surgical outcome indicators, BCVA, intraocular pressure (IOP) change, foveal thickness, and VEGF level in aqueous humor. Indicators in RG were obviously higher than in CG, such as treatment success rate and surgical outcome indicators. Conversely, lower postoperative complication rate, postoperative BCVA, IOP, retinal fovea thickness, and VEGF level in aqueous humor were found in RG than in CG. Therefore, the study reached the following conclusions about vitrectomy assisted by Lucentis: (1) it effectively increases the success rate of treatment, decreases postoperative complications as well as surgical risks, and improves patients' vision; (2) it promotes the recovery of IOP, reduces macular edema and VEGF levels in aqueous humor, and inhibits the neonatal formation of blood vessels. It is finally confirmed that Lucentis adjuvant PPV in the treatment of DR complicated with NVG is safe and feasible.

Clinical Manifestations of Supra-Large Range Nonperfusion Area in Diabetic Retinopathy

OBJECTIVE

We describe the clinical manifestations of supra-large range nonperfusion area (SLRNPA) in diabetic retinopathy (DR).

METHODS

This was a retrospective case-control study. A total of 260 eyes of 236 patients with DR who underwent pars plana vitrectomy in the Department of Ophthalmology of Qingdao Municipal Hospital from February 2016 to June 2019 were enrolled. Fundus fluorescein angiography was performed after surgery to determine whether SLRNPA or non-SLRNPA in DR was present. All demographic and clinical data were carefully collected.

RESULTS

Forty-one eyes of 22 patients were diagnosed with SLRNPA in DR (15.77% of all eyes). Compared to non-SLRNPA, SLRNPA patients were more likely to be male and younger with earlier DR onset, a smoking history, other comorbidities, and a higher HbA1c level. SLRNPA in DR eyes exhibited more neovascular glaucoma (NVG) and diabetic keratopathy (DK) than did other eyes. Such eyes were more likely to require anti-VEGF therapy before surgery or a silicone oil or a gas tamponade during surgery and to suffer from persistent corneal epithelial erosion and NVG recurrence after surgery.

CONCLUSIONS

SLRNPA in DR is a severe status of DR. Treatment for DR patients with SLRNPA is difficult, and the prognosis is poor, so clinicians must thus pay more attention to SLRNPA in DR.

Is Chronic Kidney Disease Affecting the Postoperative Complications of Vitrectomy for Proliferative Diabetic Retinopathy?

Chronic kidney disease (CKD) is a well-known risk factor for postoperative complications in several surgical fields. However, although prevalent among diabetic candidates for vitrectomy, the effect of CKD on vitrectomy outcomes remains unclear. This study aimed at clarifying the relationship between CKD and the occurrence of vitrectomy-related complications in patients with proliferative diabetic retinopathy (PDR). The 6-month incidences of vitreous hemorrhage (VH) and neovascular glaucoma (NVG) following vitrectomy for PDR were compared among the following groups: stages 1–2 CKD (60 patients), stages 3–5 CKD (70 patients not on hemodialysis), and hemodialysis (HD; 30 patients). We also determined whether the deterioration of the estimated glomerular filtration rate (eGFR) was associated with post-vitrectomy events. The incidence of VH was significantly higher in the stages 3–5 CKD group (43%) than in the stages 1–2 CKD (10%) and HD (10%) groups. NVG was more common in the stages 3–5 CKD group (17%) than in the stages 1–2 CKD (2%) and HD (0%) groups. The reduced estimated glomerular filtration rate (eGFR) was the only significant variable associated with post-vitrectomy VH and NVG. Patients with PDR and CKD, particularly those with lower eGFR, might be at risk for post-vitrectomy VH and NVG.

Potential bias of preoperative intravitreal anti-VEGF injection for complications of proliferative diabetic retinopathy

PURPOSE

Intravitreal anti-VEGF injection (IVI) is administered before vitrectomy to assist management of proliferative diabetic retinopathy (PDR)-related complications. In the clinical setting, retinal surgeons determine the use of preoperative IVI based on individual criteria. In this study, we investigated factors related to the potential bias of retinal surgeons in using IVI prior to vitrectomy for PDR-related complications, and evaluated the real-world outcomes of surgeon-determined preoperative IVI.

METHODS

Medical records of 409 eyes of 409 patients who underwent 25-gauge vitrectomy for PDR complications at seven Japanese centers (22 surgeons) were retrospectively reviewed. Ocular factors, demographic and general clinical factors, surgical procedures, and postoperative complications were compared between IVI group (patients who received preoperative IVI; 87 eyes, 21.3%) and non-IVI group (patients who did not receive preoperative IVI; 322 eyes, 78.7%). In addition, baseline HbA1c in IVI group and non-IVI group was compared between eyes with and without postoperative complications.

RESULTS

At baseline, IVI group was younger (P<0.001), had shorter duration of diabetes treatment (P = 0.045), and higher frequencies of neovascular glaucoma [NVG] (P<0.001) and tractional retinal detachment [TRD] (P<0.001) compared to non-IVI group. Although IVI group had higher frequencies of intraoperative retinal break and tamponade procedure, there were no significant differences in postoperative complications and additional treatments between two groups. Baseline HbA1c levels were also not correlated with postoperative complications of VH, NVG, and RD both in IVI group and non-IVI group. Logistic regression analysis identified age (P<0.001, odds ratio [OR] 0.95), presence of NVG (P<0.001, OR 20.2), and presence of TRD (P = 0.0014, OR 2.44) as preoperative factors in favor of IVI.

CONCLUSIONS

In this multicenter real-world clinical study, younger age and presence of NVG and TRD were identified as potential biases in using IVI before vitrectomy for PDR complications. Eyes that received preoperative IVI had more intraoperative retinal breaks requiring tamponade than eyes not receiving IVI, but postoperative outcome was not different between the two groups.

Neovascular Glaucoma after Diabetic Vitrectomy: Incidence and Risk Factors

Purpose: The prevalence and risk factors of neovascular glaucoma (NVG) after diabetic vitrectomy were evaluated. Methods: This retrospective study included 171 eyes of 141 patients who underwent diabetic vitrectomy in-hospital between March 2013 and July 2019 and were followed for >12 months postoperatively. Regardless of the presence or absence of neovascularization in the anterior segment, all patients received injections of intravitreal bevacizumab during vitrectomy. Patients with preoperative neovascularization in iris (NVI) or angle (NVA) received both intracameral and intravitreal bevacizumab injections. Data were collected regarding baseline demographics, preoperative best-corrected visual acuity, intraocular pressure, hypertension, NVG in the fellow eye, panretinal photocoagulation history, iris and angle neovascularization, and postoperative findings (e.g., rebleeding and residual retinal detachment). Results: In total, 141 patients and 171 eyes were included in the study, and the incidence of postoperative NVG was 5.85% (10 patients). Five patients (27.78%) with preoperative NVI or NVA developed postoperative NVG. Significant risk factors for postoperative NVG were preoperative NVA or NVI (odds ratio [OR] = 16.428, p = 0.003), shorter diabetic duration (OR = 0.853, p = 0.033), and the absence of preoperative panretinal photocoagulation (OR = 0.006, p = 0.035). Conclusions: There is a high possibility of postoperative NVG in patients with preoperative NVI or NVA, a short duration of diabetes, and no preoperative panretinal photocoagulation. In such patients, close monitoring is required after diabetic vitrectomy.

INTERNAL LIMITING MEMBRANE PEELING DURING VITRECTOMY FOR DIABETIC VITREOUS HEMORRHAGE: A Randomized Clinical Trial

PURPOSE

To evaluate the benefits of internal limiting membrane peeling in proliferative diabetic retinopathy subjects undergoing pars plana vitrectomy for the treatment of vitreous hemorrhage.

METHODS

Two hundred and fifty-eight proliferative diabetic retinopathy subjects undergoing pars plana vitrectomy for vitreous hemorrhage were enrolled into the trial. Patients were randomized into one of two cohorts: Group A patients underwent internal limiting membrane peeling, whereas Group B patients did not undergo internal limiting membrane peeling. The main outcome was best-corrected visual acuity at 6 months. Secondary outcomes were optical coherence tomography central macular thickness at 6 months, incidence of diabetic macular edema treatment during the postoperative trial period, and incidence of epiretinal membrane at 6 months.

RESULTS

Two hundred and seven patients were randomized and completed 6 months follow-up. Group A had better best-corrected visual acuity at 6 months than Group B (P < 0.01). Group A had a lower incidence of diabetic macular edema treatment during the postoperative trial period and a lower incidence of epiretinal membrane at 6 months than Group B (P = 0.02 and P < 0.001, respectively). There was a trend toward lower central macular thickness on optical coherence tomography in Group A than Group B (P = 0.09). There were no significant differences in baseline details or complications intraoperatively or postoperatively between cohorts.

CONCLUSION

This trial demonstrated better vision, fewer postoperative diabetic macular edema treatments, and a lower incidence of epiretinal membrane at 6 months when internal limiting membrane peeling was performed. Internal limiting membrane peeling may be considered a vital maneuver to perform in proliferative diabetic retinopathy subjects undergoing pars plana vitrectomy for vitreous hemorrhage.

The incidence and risk factors of neovascular glaucoma secondary to proliferative diabetic retinopathy after vitrectomy

OBJECTIVE

The incidence and risk factors of neovascular glaucoma (NVG) secondary proliferative diabetic retinopathy (PDR) after pars plana vitrectomy (PPV) are unclear and reports in the published literature are inconsistent. Therefore, a systematic review and meta-analysis were conducted to clarify the risk factors associated with neovascular glaucoma.

METHODS

PubMed, Embase, and The Cochrane Library were systematically searched without language limitations for studies related to NVG after PPV in PDR patients. We used R software to fit the correlation between incidence and the date of publication for studies and performed a Spearman analysis. For binary and continuous variables, the odds ratios (ORs) with 95% confidence intervals (CIs) were pooled, respectively, using Review Manager 5.3 (The Cochrane Collaboration).

RESULTS

Twenty-six studies with 5161 patients were included in our meta-analysis. The overall pooled incidence of NVG after PPV in PDR patients was 6% (95% CI, 0.05-0.07, p-value < 0.00001). Pooled estimates indicated a positive correlation for NVG after PPV in PDR patients with higher baseline IOP (OR, 1.26; 95%CI,0.56-1.95, p-value = 0.0004), preoperative iris neovascularization (INV) (OR, 5.66; 95% CI, 2.10-15.23, p-value = 0.0006), preoperative or intraoperative combined cataract surgery (OR, 2.00; 95% CI, 1.15-3.46, p-value = 0.01), postoperative vitreous hemorrhage (VH) (OR, 3.53; 95% CI, 1.63-7.66, p-value = 0.001), and a negative correlation with age (OR, -2.90; 95%CI, -5.00 to -0.81, p-value < 0.007).

CONCLUSION

Our systematic review and meta-analysis indicated that the main risk factors for NVG after PPV in PDR patients included higher baseline IOP, preoperative INV, preoperative or intraoperative combined cataract surgery, postoperative VH, and was negatively correlated with age.