Frequency and Risk Factors for Neovascular Glaucoma After Vitrectomy in Eyes with Diabetic Retinopathy: An Observational Study

Updates on medical and surgical managements of diabetic retinopathy and maculopathy

Diabetic retinopathy (DR) and diabetic macular edema (DME) are leading causes of vision loss globally. This is a comprehensive review focused on both medical and surgical management strategies for DR and DME. This review highlights the epidemiology of DR and DME, with a particular emphasis on the Asia-Pacific region, urban-rural disparities, ethnic variations, and grading methodologies. We examine various risk factors for DR, including glycemic control, hypertension, hyperlipidemia, obesity, chronic kidney disease, sex, myopia, pregnancy, and cataract surgery. Furthermore, we explore potential biomarkers in serum, proteomics, metabolomics, vitreous, microRNA, and genetics that may aid in the detection and management of DR. In addition to medical management, we review the evidence supporting systemic and ocular treatments for DR/DME, including anti-vascular endothelial growth factor (anti-VEGF) agents, anti-inflammatory agents, biosimilars, and integrin inhibitors. Despite advancements in treatment options such as pan-retinal photocoagulation and anti-VEGF agents, a subset of cases still progresses, necessitating vitrectomy. Challenging diabetic vitrectomies pose difficulties due to complex fibrovascular proliferations, incomplete posterior vitreous detachment, and fragile, ischemic retinas, making membrane dissection risky and potentially damaging to the retina. In this review, we address the question of challenging diabetic vitrectomies, providing insights and strategies to minimize complications. Additionally, we briefly explore newer modalities such as 3-dimensional vitrectomy and intra-operative optical coherence tomography as potential tools in diabetic vitrectomy. In conclusion, this review provides a comprehensive overview of both medical and surgical management options for DR and DME. It underscores the importance of a multidisciplinary approach, tailored to the needs of each patient, to optimize visual outcomes and improve the quality of life for those affected by these sight-threatening conditions.

Early postoperative bevacizumab for preventing neovascular glaucoma in phacovitrectomy for proliferative diabetic retinopathy

To evaluate the effectiveness of postoperative intravitreal bevacizumab (IVB) in preventing neovascular glaucoma (NVG) and identify associated risk factors in patients with proliferative diabetic retinopathy (PDR) undergoing phacovitrectomy. Patients with PDR who underwent phacovitrectomy were enrolled and categorized into two subgroups based on their postoperative treatment regimen: one group received IVB within 2 months following phacovitrectomy (Group 1); the other did not receive IVB during this period (Group 2). A comparative analysis evaluated the distinguishing characteristics of the two groups after 1:1 propensity score matching. Kaplan-Meier survival analysis was utilized to determine the incidence of NVG after phacovitrectomy. Multivariate analysis with the Cox proportional hazards model identified risk factors associated with NVG postphacovitrectomy. A total of 206 eyes of 206 patients were investigated in this study. NVG developed in 15 eyes (7.28%). The probabilities of NVG occurrence at 6, and 12 months following phacovitrectomy were 4.85%, and 7.28%, respectively. When comparing Groups 1 (n = 57) and 2 (n = 57), a significant difference was observed in the occurrence of NVG (P < 0.001). In Group 1, only one case of NVG (1.75%) were noted, whereas all other NVG cases occurred in Group 2 (9.39%). Male sex and high preoperative intraocular pressure (IOP) were associated with NVG occurrence following phacovitrectomy, and the administration of IVB within 2 months postphacovitrectomy demonstrated efficacy in preventing the development of NVG. Male sex and high preoperative IOP were associated with a higher incidence of NVG, and postoperative IVB had a protective effect against NVG occurrence.

The effect of leizumab on serum vascular endothelial growth factor, IL-6, MCP-1 inflammatory factors in neovascular glaucoma

This study aimed to assess Leizumab's effect on serum endothelial growth factor, interleukin-6 (IL-6), monocyte chemotactic protein-1 (MCP-1), and inflammatory factors in neovascular glaucoma patients. 80 eligible patients treated between January 2021 and April 2023 were enrolled, randomly divided into control and study groups. The control group underwent vitrectomy while the study group received preoperative intravitreal rituximab injection. Measurements included serum and aqueous humor VEGF/PEDF, IL-6/MCP-1 levels, postoperative rebleeding/retinal detachment, and visual acuity changes over 6 weeks. After surgery, patients showed reduced serum VEGF/PEDF levels (P < 0.05), with decreased VEGF and increased PEDF in aqueous humor (P < 0.05). The study group had lower VEGF and higher PEDF levels than the control (P < 0.05). Serum IL-6/MCP-1 levels reduced post-surgery, with the study group lower than control (P < 0.05). Intraocular rebleeding was lower in the study group (P < 0.05), while retinal detachment rates were similar (P > 0.05). Visual acuity differed significantly from week 1 to 6 post-surgery (P < 0.05), with higher acuity in the study group during weeks 1-4 (P < 0.05). Weeks 5-6 follow-up showed no significant difference (P > 0.05). Pre-vitrectomy ranibizumab injection effectively reduced bleeding, VEGF/PEDF levels, inflammatory factors, and improved visual recovery.

Incidence and risk factor analysis of neovascular glaucoma following vitrectomy in patients with proliferative diabetic retinopathy

To investigate the incidence and risk factors for neovascular glaucoma (NVG) after vitrectomy in patients with proliferative diabetic retinopathy (PDR). Patients were categorized into two subgroups based on their treatment regimen: one group received vitrectomy only (Group 1), while the other received combined phacovitrectomy (Group 2). A comparative analysis was conducted to evaluate the distinguishing characteristics of the two groups. Kaplan-Meier survival analysis was used to determine the incidence of NVG following surgery. Furthermore, multivariate analysis using the Cox proportional hazards model was conducted to identify the risk factors associated with the development of NVG after surgery. A total of 484 eyes of 484 patients were included in the study. When comparing Group 1 with Group 2, a significant difference was observed in the occurrence of NVG. In Group 1, there were 10 cases of NVG (3.9%), whereas 29 cases of NVG occurred in Group 2 (12.71%). Male sex, high preoperative intraocular pressure (IOP), and combined phacovitrectomy were found to be associated with the occurrence of NVG following phacovitrectomy. Higher creatinine levels had a protective effect in preventing the development of NVG. Male sex, high preoperative IOP, and combined phacovitrectomy were associated with a high incidence of NVG. Explore strategies to prevent NVG is important when performing combined phacovitrectomy in patients with PDR.

Increased late-onset glaucoma risk following vitrectomy for macular pucker or hole

OBJECTIVES

The long-term risk of developing glaucoma after vitrectomy remains uncertain. This retrospective population-based cohort study aimed to explore this risk following vitrectomy for macular pucker or hole.

METHODS

Utilizing Taiwan's National Health Insurance Research Database (NHIRD), we included patients who were older than 18 years and had undergone vitrectomy surgery between 2011 and 2019. Exclusions were made for patients with prior diagnoses of glaucoma, congenital or secondary glaucoma, as well as those who had received previous vitreoretinal treatments or had undergone multiple vitrectomies.

RESULTS

After an average follow-up period of 51 and 53 months respectively for the vitrectomized and non-vitrectomized group, our results showed a relative risk of 1.71 for glaucoma development in the vitrectomized group. Higher adjusted hazard ratios were also observed for open-angle glaucoma and normal tension glaucoma. Increased risks were associated with male sex, obstructive sleep apnoea, and migraine. In the subgroup analysis, phakic eyes at baseline and those who had undergone cataract surgery post-vitrectomy were associated with a lower risk of glaucoma development during follow-up. Among all glaucoma events, pseudophakic status at baseline had the shortest interval to glaucoma development following vitrectomy.

CONCLUSIONS

These findings underscore the potential relationship between vitrectomy and glaucoma onset, emphasizing the need for vigilant monitoring and early detection of glaucoma in post-vitrectomy patients.

Clinical Efficacy of Preoperative and Intraoperative Intravitreal Ranibizumab as Adjuvant Therapy of Ahmed Glaucoma Valve Implantation Combined with Vitrectomy in the Management of Neovascular Glaucoma with Diabetic Vitreous Hemorrhage

Neovascular glaucoma (NVG) secondary to proliferative diabetic retinopathy (PDR) is a devastating ocular disease with poor prognosis. Intravitreal ranibizumab injection (IVR) has been used as adjuvant therapy of surgical interventions preoperatively or intraoperatively. This study aimed to determine the efficacy and safety of combined IVR as adjuvant therapy in treating NVG with vitreous hemorrhage (VH) in PDR. A total of 39 NVG patients with VH (39 eyes) received IVR 3 to 5 days before surgery, and then they were assigned to either pars plana vitrectomy (PPV) + Ahmed glaucoma valve (AGV) implantation (Group 1, n = 22) or PPV + AGV implantation + intraoperative IVR (Group 2, n = 17). Patients were followed up for at least 9 months. Intraocular pressure (IOP), anti-glaucoma medications, best corrected visual acuity (BCVA), surgical success rates and postoperative complications were compared. Results showed that IOP decreased promptly after surgery and was notably maintained at a mid-term follow-up in both groups, and no significant differences were observed (all p > 0.05). Additional intraoperative IVR significantly reduced postoperative recurrent VH and iris neovascularization (p = 0.047, p = 0.025, respectively). There was no remarkable difference in postoperative anti-glaucoma medications, BCVA and complications between two groups (all p > 0.05). In conclusion, preoperative and intraoperative IVR as adjuvant therapy of AGV implantation combined with PPV could be a safe and effective treatment for NVG with VH in PDR. An additional intraoperative anti-VEGF injection could significantly reduce postoperative VH and iris neovascularization.

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.

Two-year outcomes of patients presenting to Sydney Eye Hospital with neovascular glaucoma

BACKGROUND

Neovascular glaucoma (NVG) is a sight-threatening condition that is often refractory to treatment. Current management principles are yet to be standardized due to lack of evidence. We studied the interventions used to treat NVG at Sydney Eye Hospital (SEH) and the two-year surgical outcomes.

METHODS

We performed a retrospective audit of 67 eyes of 58 patients with NVG from January 1, 2013, to December 31, 2018. Intraocular pressure (IOP), best-corrected visual acuity (BCVA), number of medications, repeat surgery, recurrent neovascularization, loss of light perception and pain were studied.

RESULTS

The average age of the cohort was 59.67 years (SD 14.22). The most common etiologies were proliferative diabetic retinopathy (35 eyes; 52.2%), central retinal vein occlusion (18 eyes; 26.9%) and ocular ischemic syndrome (7 eyes; 10.4%). 70.1% of eyes (47) received vascular endothelial growth factor injections (VEGFI), 41.8% (28 eyes) received pan-retinal photocoagulation (PRP) and 37.3% (25 eyes) received both prior to or within the first week of presentation to SEH. The most common initial surgical interventions were trans-scleral cyclophotocoagulation (TSCPC) (36 eyes; 53.7%) and Baerveldt tube insertion (18 eyes; 26.9%). 62.7% of eyes (42 eyes) failed (IOP > 21 or < 6 mmHg for two consecutive reviews, further IOP-lowering surgery or loss of light perception) during follow-up. Initial TSCPC failed in 75.0% (27/36 eyes) compared with 44.4% (8/18 eyes) after Baerveldt tube insertion.

CONCLUSION

Our study reinforces the refractory nature of NVG, often despite intensive treatment and surgery. Improvements in patient outcomes may be achieved with earlier consideration of VEGFI and PRP. This study identifies the limitations of surgical interventions for NVG and highlights the need for a standardized management approach.

Review: The Development of Risk Factors and Cytokines in Retinal Vein Occlusion

Retinal vein occlusion (RVO) is the second most prevalent retinal disease. Despite this, the pathogenic mechanisms and risk factors are not entirely clear. In this article, we review recent publications on the classification, pathogenesis, risk factors, ischemic changes, cytokines, and vital complications of RVO. Risk factors and cytokines are important for exploring the mechanisms and new treatment targets. Furthermore, risk factors are interrelated, making RVO mechanisms more complex. Cytokines act as powerful mediators of pathological conditions, such as inflammation, neovascularization, and macular edema. This review aims to summarize the updated knowledge on risk factors, cytokines of RVO and signaling in order to provide valuable insight on managing the disease.

Neovascular glaucoma following Nd:YAG laser capsulotomy: a rare complication in a postvitrectomised patient with diabetes

To describe a case of acute-onset neovascular glaucoma (NVG) after a neodymium:yttrium-aluminium-garnet (Nd:YAG) capsulotomy in a diabetic vitrectomized eye of a patient with severe systemic and ocular comorbidities. A man in his 50s underwent a Nd:YAG capsulotomy for visually significant posterior capsular opacification with a previous history of vitrectomy with silicone oil in situ for diabetic retinopathy. He had systemic and ocular comorbidities implicating an advanced ischaemic status, both systemically and locally. Five days post Nd:YAG capsulotomy, extensive neovascularisation of the iris and angles was noted. Despite maximum antiglaucoma medication, an evisceration ensued due to intractable NVG. This case report highlights the importance of irreversible complications after a seemingly simple capsulotomy in eyes with advanced ocular conditions and systemic comorbidities necessitating extreme caution.

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.

[Effectiveness of multistage surgical treatment of advanced proliferative diabetic retinopathy complicated with primary cataract]

Vitreoretinal surgery (VRS) is the «gold standard» for surgical treatment of patients with proliferative diabetic retinopathy (PDR). However, the timing for the removal of primary cataract in this category of patients remains uncertain.

PURPOSE

To evaluate the effectiveness of multistage surgical treatment of patients with advanced PDR complicated with primary cataract.

MATERIAL AND METHODS

The study involved 94 cases of surgical treatment of patients with PDR and complicated primary cataract. These patients were divided into two groups depending on the treatment tactics. In the first group, patients were subjected to a two-step surgical procedure: VRS with silicone oil tamponade performed as the first step in their treatment followed by phacoemulsification, silicone oil removal, and IOL implantation, respectively, as the second step. In subgroup 1a - VRS was performed with standard pharmacological support. In subgroup 1b - intravitreal injection of angiogenesis inhibitors preceded VRS. In the second group, the first step was phacoemulsification performed simultaneously with vitreoretinal surgery with silicone oil tamponade; the second step consisted of removing silicone oil from the vitreous cavity. Subgroup 2a - surgical treatment was performed with standard pharmacological support (similar to subgroup 1a). Subgroup 2b - intravitreal injection of anti-VEGF drugs preceded VRS.

RESULTS

Visual functions improved in 88.8% and 83.4% of cases in subgroups 1a and 1b, and in 51.3% and 66.7% in subgroups 2a and 2b, respectively.

CONCLUSIONS

The study confirms the effectiveness of staged (multi-step) surgical treatment of patients with advanced proliferative diabetic retinopathy and complicated primary cataract. Conducting phacoemulsification sometime later along with silicone oil removal in PDR patients with preoperative intravitreal injection of angiogenesis inhibitors is a gentler approach for the anatomic structures of the eye during the first stage (VRS) and contributes to the reduction in the number of intraoperative and postoperative complications.

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.

Tube Length Adjustment and Tube Trimming Technique in Refractory Glaucoma

Secondary glaucoma may develop after vitreoretinal surgery as it is a known risk factor for its development. When the risk factors are more than one, for instance along with neovascular glaucoma (NVG), the secondary glaucoma may become recalcitrant and very difficult to manage. Surgical intervention is often warranted to control intraocular pressure (IOP) and prevent progressive glaucomatous damage in patients with refractory glaucoma, and glaucoma drainage implant may be preferred as the primary choice. We describe a patient who develop secondary glaucoma after vitrectomy and silicone oil (SO) injection due to unresolved vitreous hemorrhage in proliferative diabetic retinopathy (PDR) and subsequent NVG. Baerveldt glaucoma implant (BGI) was carried out and placed in the superotemporal quadrant with longer anterior chamber tube placement to prevent escape of SO through the tube. Qualified success was achieved with additional one fixed-drug combination (FDC). However, 3 years later, the tube was blocked by the iris tissue at the inferior edge of the pupil. Tube trimming was performed efficiently using a simple technique. The distal end of the tube was pulled out of the anterior chamber through a paracentesis just next to the tube entrance and trimmed to the appropriate length. More than a year after the surgery, IOP was still well controlled with the same FDC. Unfortunately, the visual acuity could not be recovered due to advanced PDR.

Decreased Ratio of VEGF165b/VEGF in Aqueous Humor Predicts Progression of Diabetic Retinopathy

BACKGROUND

Different splicing of vascular endothelial growth factor (VEGF) gene results in 2 families of VEGF, the proangiogenic isoforms (VEGFxxxa) and the antiangiogenic isoforms (VEGFxxxb). VEGF165b is the major antiangiogenic isoform of VEGF and the most studied member of the VEGFxxxb family so far.

OBJECTIVES

To determine the concentration of VEGF165b and VEGF in the aqueous humor (AH) in diabetic eyes with or without diabetic retinopathy (DR) and to address the predictive value of VEGF165b/VEGF ratio for progression of DR.

METHODS

AH samples from 20 eyes in healthy controls (CON group), 40 eyes in diabetic patients without DR (nDR group), and 30 eyes in diabetic patients with mild nonproliferative DR (DR group) were collected. All of the patients were followed up for at least 5 years. VEGF165b and VEGF levels of AH samples were measured by enzyme-linked immunosorbent assay (ELISA). The predictive value of the initial VEGF165b/VEGF ratio for progression of DR was studied.

RESULTS

The mean concentration of VEGF165b significantly decreased in diabetic eyes vs. controls. The mean concentration of VEGF significantly increased in the DR group vs. the CON group. The VEGF165b/VEGF ratio was significantly lower in diabetic patients compared to the CON group. The VEGF165b/VEGF ratio was significantly lower in diabetic patients compared to the control group. The mean follow-up was 66.1months (range 60-71 months). The risk of DR progression was greater with a lower VEGF165b/VEGF ratio.

CONCLUSION

The VEGF165b/VEGF ratio is lower in the AH of DR patients and the decreased ratio of VEGF165b/VEGF predicts DR progression.