VISUAL AND ANATOMICAL OUTCOMES AFTER DIABETIC TRACTION AND TRACTION-RHEGMATOGENOUS RETINAL DETACHMENT REPAIR

Advances in the development of lipid nanoparticles for ophthalmic therapeutics

Previously, researchers have employed Lipid nanoparticles (LNPs) to directly encapsulate medicines. In the realm of gene therapy, researchers have begun to employ lipid nanoparticles to encapsulate nucleic acids such as messenger RNA, small interfering RNA, and plasmid DNA, which are known as nucleic acid lipid nanoparticles. Recent breakthroughs in LNP-based medicine have provided significant prospects for the treatment of ocular disorders, such as corneal, choroidal, and retinal diseases. The use of LNP as a delivery mechanism for medicines and therapeutic genes can increase their effectiveness while avoiding undesired immune reactions. However, LNP-based medicines may pose ocular concerns. In this review, we discuss the general framework of LNP. Additionally, we review adjustable approaches and evaluate their possible risks. In addition, we examine newly described ocular illnesses in which LNP was utilized as a delivery mechanism. Finally, we provide perspectives for solving these potential issues.

SURGICAL OUTCOMES IN CONCURRENT SICKLE CELL AND DIABETIC RETINOPATHY

PURPOSE

To report the clinical features and outcomes in eyes that underwent vitreoretinal surgery for complications of concurrent sickle cell retinopathy and diabetic retinopathy.

METHODS

Retrospective, consecutive case series of all eyes that underwent vitreoretinal surgery for complications secondary to concurrent sickle cell retinopathy and diabetic retinopathy between January 01, 2014, and December 31, 2021.

RESULTS

The study included 20 eyes of 14 patients. Indications for surgery included tractional retinal detachment in 12 eyes (60%), combined tractional retinal detachment/rhegmatogenous retinal detachment in 6 eyes (30%), and vitreous hemorrhage in 2 eyes (10%). Pars plana vitrectomy was performed in all eyes. One eye received a scleral buckle at the same time as pars plana vitrectomy. There was no change in mean best-corrected visual acuity at the last follow-up examination (1.5 [20/678]) when compared with mean preoperative best-corrected visual acuity (1.6 [20/762], P = 0.83). Preoperative best-corrected visual acuity correlated with postoperative best-corrected visual acuity at the last follow-up examination in eyes with retinal detachment (r = 0.49, P = 0.04). Single operation anatomic success was achieved in 11 of 17 eyes (65%) with retinal detachment.

CONCLUSION

Functional and anatomic outcomes after surgery in eyes with concurrent sickle cell retinopathy and diabetic retinopathy are relatively poor.

Advances in development of exosomes for ophthalmic therapeutics

Exosomes contain multiple bioactive molecules and maintain the connection between cells. Recent advances in exosome-based therapeutics have witnessed unprecedented opportunities in treating ophthalmic diseases, including traumatic diseases, autoimmune diseases, chorioretinal diseases and others. Utilization of exosomes as delivery vectors to encapsulate both drugs and therapeutic genes could yield higher efficacy and avoid the unnecessary immune responses. However, exosome-based therapies also come with some potential ocular risks. In this review, we first present a general introduction to exosomes. Then we provide an overview of available applications and discuss their potential risks. Moreover, we review recently reported exosomes as delivery vectors for ophthalmic diseases. Finally, we put forward future perspectives to grapple with its translation and underlying issues.

Functional and structural outcomes and complications after pars plana vitrectomy for severe features of proliferative diabetic retinopathy in type 1 and type 2 diabetes mellitus

PURPOSE

To evaluate the functional and structural outcomes as well as postoperative complications after pars plana vitrectomy (PPV) for severe features of proliferative diabetic retinopathy (PDR) in type 1 and type 2 diabetes mellitus (DM) patients.

METHODS

Twenty two eyes of type 1 diabetics (DM1 group) and 27 eyes of type 2 diabetics (DM2 group) were included. Best corrected visual acuity (BCVA), intraocular pressure (IOP), postoperative structural changes in optical coherence tomography (OCT) and postoperative complications such as recurrent vitreous haemorrhage, diabetic macular oedema, secondary glaucoma and persistent tractional retinal detachment (TRD) were assessed and compared between the two groups.

RESULTS

Complete reattachment of retina was achieved in 88.9% from the DM1 group and in 95.5% from the DM2 group and remained attached in follow-up. BCVA in DM2 group was significantly lower preoperatively (p = 0.04). Mean postoperative BCVA significantly improved in both studied groups, but it was more evident in eyes of type 2 diabetics compared to type 1 diabetics. In eyes in the DM1 group there was perceptible stabilisation of BCVA. Poor visual acuity or lack of improvement in BCVA in the DM1 group was related to preoperative subretinal haemorrhage in macular region, and TRD involving macula, whereas in the DM2 group-to preoperative subretinal haemorrhage and neovascular glaucoma. The postoperative structural changes (disruption of EZ and ELM) were observed more often in DM2 group, but had the greatest impact on BCVA in eyes of type 1 DM. Complications after PPV for PDR were rare and hadn't a significant influence on the final functional outcomes in both groups.

CONCLUSIONS

Functional improvement after PPV for severe features of proliferative diabetic retinopathy were more noticeable in patients with type 2 DM. Postoperative structural changes had more negative impact on BCVA in type 1 diabetics.

Clinical Outcomes of 27-Gauge Pars Plana Vitrectomy for Diabetic Tractional Retinal Detachment Repair

Purpose: To analyze the clinical outcomes of 27-gauge pars plana vitrectomy (PPV) repair of diabetic tractional retinal detachment (TRD) of various severities. Methods: This retrospective case series examined the outcomes of 27-gauge PPV to repair diabetic TRD from 2016 to 2020. The effect of medical and ophthalmologic history parameters and baseline detachment characteristics on visual acuity (VA) and retinal reattachment was analyzed. A grading system was established to stage the severity of the baseline vitreoretinal traction or detachment and compare the visual and anatomic outcomes between stages. Results: The study comprised 79 eyes (79 patients). The overall redetachment rate was 10.1% (8/79). The proportion of eyes with severe visual impairment (worse than 20/200) decreased from 81.0% (64/79) preoperatively to 56.9% (37/65) 6 months postoperatively (P < .001). Worse preoperative logMAR VA was associated with greater odds of redetachment (P = .017) and worse postoperative VA (P < .001). Insulin dependence was associated with better VA at 6 months (P = .017). A shorter known duration of diabetes (P = .026) and evidence of neovascularization of the iris (NVI) or angle (P = .004) were associated with worse visual outcomes. Eyes with detachment involving the posterior pole extending beyond the equator had worse VA at 6 months (P = .048). Conclusions: The primary reattachment rate after 27-gauge PPV was 89.9%. There was significant VA improvement, with a roughly 40% reduction in the number of eyes with severe visual impairment by the final follow-up. Insulin dependence, duration of diabetes, presence of NVI before surgery, and baseline posterior pole detachment extending beyond the equator were predictors of visual outcomes.

Comparison of the adjuvant effect of conbercept intravitreal injection at different times before vitrectomy for proliferative diabetic retinopathy

Purpose

To assess the optimal time of intravitreal conbercept (IVC) treatment prior to pars plana vitrectomy (PPV) in patients with severe proliferative diabetic retinopathy (PDR).

Method

This study was exploratory in nature. Forty-eight consecutive patients (48 eyes) with PDR were divided into four groups according to different IVC times (0.5 mg/0.05 mL) before PPV: group A (3 days), group B (7 days), group C (14 days), and group D (non-IVC). Intraoperative and postoperative effectiveness were assessed, and vitreous VEGF concentrations were detected.

Result

For intraoperative effectiveness, groups A and D had a higher incidence of intraoperative bleeding than groups B and C (P = 0.041). Furthermore, groups A-C required less surgical time than group D (P < 0.05). For postoperative effectiveness, group B had a significantly higher proportion of visual acuity that improved or remained unchanged than group D (P = 0.014), and groups A-C had lower proportions of postoperative bleeding than group D. The vitreous VEGF concentration of group B (67.04 ± 47.24 pg/mL) was significantly lower than that of group D (178.29 ± 110.50 pg/mL) (P = 0.005).

Conclusion

IVC treatment that was administered 7 days preoperatively was associated with better effectiveness and a lower vitreous VEGF concentration than its administration at other time points.

Pre-operative intravitreal bevacizumab for tractional retinal detachment secondary to proliferative diabetic retinopathy: the Alvaro Rodriguez lecture 2023

The treatment of proliferative diabetic retinopathy (PDR) has evolved significantly since the initial use of panretinal photocoagulation as a treatment in the 1950s. Vascular endothelial growth factor inhibitors have provided an effective alternative without the risk of peripheral vision loss. Despite this, the risk of complications requiring surgical intervention in PDR remains high. Intravitreal bevacizumab has shown promise as a preoperative adjuvant to vitrectomy for PDR complications, albeit with a purported risk for tractional retinal detachment (TRD) progression in eyes with significant fibrous proliferation. Here we will discuss anti-VEGF agent use in PDR and its role in surgical intervention for PDR complications including TRD.

TREM2 deficiency in microglia accelerates photoreceptor cell death and immune cell infiltration following retinal detachment

Retinal detachment (RD) occurs in several major retinal conditions and often causes irreversible vision loss due to photoreceptor cell death. Retinal residential microglial cells are activated following RD and participate in photoreceptor cell death via direct phagocytosis and the regulation of inflammatory responses. Triggering receptor expressed on myeloid cells 2 (TREM2) is an innate immune receptor exclusively expressed on microglial cells in the retina, and has been reported to affect microglial cell homeostasis, phagocytosis and inflammatory responses in the brain. In this study, increased expression of multiple cytokines and chemokines in the neural retina was observed starting at 3 h following RD. Trem2 knockout (Trem2^-/-) mice exhibited significantly more photoreceptor cell death than wild-type controls at 3 days after RD, and the number of TUNEL positive photoreceptor cells progressively decreased from day 3 to day 7 post-RD. A significant thinning of the outer nuclear layer (ONL), with multiple folds was observed in the Trem2^-/- mice at 3 days post-RD. Trem2 deficiency reduced microglial cell infiltration and phagocytosis of stressed photoreceptors. There were more neutrophils in Trem2^-/- retina following RD than in controls. Using purified microglial cells, we found Trem2 knockout is associated with increased CXCL12 expression. The aggravated photoreceptor cell death was largely reversed by blocking the CXCL12-CXCR4 mediated chemotaxis in Trem2^-/- mice after RD. Our findings suggested that retinal microglia are protective in preventing further photoreceptor cell death following RD by phagocytosing presumably stressed photoreceptor cells and by regulating inflammatory responses. TREM2 is largely responsible for such protective effect and CXCL12 plays an important role in regulating neutrophil infiltration after RD. Collectively, our study pinpointed TREM2 as a potential target of microglial cells to ameliorate RD-induced photoreceptor cell death.

Outcomes and Complications of Pars Plana Vitrectomy for Tractional Retinal Detachment in People With Diabetes: A Systematic Review and Meta-analysis

Importance

Tractional retinal detachment (TRD) occurs in approximately 5% of people with proliferative diabetic retinopathy and poses a threat to vision. Pars plana vitrectomy (PPV) is the treatment of choice for TRD.

Objective

To determine anatomic and functional outcomes of PPV for the treatment of TRD in people with diabetes (dTRD).

Data Sources

MEDLINE and Embase were searched systematically from January 1, 2000, to February 20, 2022. In addition, a reference list of eligible studies were screened.

Study Selection

Eligible studies were those published in English, those reporting outcomes of PPV for dTRD, and those that included more than 25 eyes and with a minimum follow-up of 3 months.

Data Extraction and Synthesis

Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines for data extraction/synthesis were followed, and the National Institute for Health quality assessment tool was used to assess risk of bias. Study eligibility was determined independently by 2 reviewers; data extraction was conducted by 1 reviewer and entries checked for accuracy by another. Data were pooled using a random-effects model.

Main Outcomes and Measures

Main outcomes included rate of failure of retinal reattachment following 1 surgery and final visual acuity (VA). The association of baseline patient characteristics and surgical maneuvers with postoperative surgical outcomes was investigated.

Results

Of the 406 studies identified, 38 (3839 eyes) were eligible and included for analysis. Patients had a median (IQR) age of 52.2 (49.6-55.7) years. In the studies reporting patient sex (31 of 38 studies), 1441 were female individuals (50.1%). The overall failure rate of retinal reattachment after 1 surgery was 5.9% (95% CI, 1.4%-8.3%), and the mean final VA was 0.94 (95% CI, 0.82-1.05) logMAR (approximate Snellen equivalent, 6/53; 95% CI, 6/39-6/71). People with higher preoperative VA achieved higher postoperative vision (0.66 logMAR worse final vision; 95% CI, 0.39-0.84 per 1.0 logMAR worse at baseline; P <.001). On multivariable analysis, no other patient characteristics or surgical variables had a statistically significant association with outcomes.

Conclusions and Relevance

Results of this systematic review and meta-analysis suggest that PPV was an effective strategy to achieve retinal reattachment in people with dTRD. Given that higher preoperative VA was the only factor associated with higher postoperative vision, early intervention should be considered and discussed in detail with patients. Overall, final postoperative VA remains low, and patients should be counseled on the guarded prognosis of dTRD.

The Learning Curve of Surgery of Diabetic Tractional Retinal Detachment-A Retrospective, Comparative Study

Background and Objectives: There are few data in the literature concerning the learning curve of tractional retinal detachment (TRD) surgery. We have analyzed the experience gained by a vitreoretinal surgeon over 10 years. Materials and Methods: A retrospective, comparative study of 34 TRD cases operated using 20G instruments between 2008 and 2011 (group A) and 94 cases operated using 23G instruments between 2015 and 2019 (group B). The preoperative characteristics, the type of endotamponade, and the anatomical and functional success were reviewed. Results: The group A patients had a significantly higher rate of concomitant vitreous hemorrhage (VH) at presentation (64.7% vs. 37.2%) and of non-macular retinal detachments (52.9% vs. 39.3%). The rate of silicone oil endotamponade was high in both groups (76.4% vs. 68.1%), but in group B 25.5% were left without a tamponade (vs. none in group A). A postoperative anatomical success was obtained in 76.5% of eyes in group A and 84.04% of eyes in group B (where it was improved to 89.3% by reinterventions). The presenting visual acuity (VA) was very low in both groups (0.01 and 0.05, respectively). The proportion of eyes with improved or stabilized VA was 85.3% in group A and 79.8% in group B (statistically non-significant difference). Conclusions: The anatomical success rate improves quite slowly with increasing surgeon experience and can be further improved by reinterventions. Visual improvement does not match the rate of anatomical improvement. With increasing experience and self-confidence, the surgeon will approach more difficult cases, a fact that may slow down the increase in surgical success rates.

PARS PLANA VITRECTOMY WITH and WITHOUT ILM-PEELING for DIABETIC PATIENTS with MACULA INVOLVED TRACTIONAL RETINAL DETACHMENT

PURPOSE

To evaluate the effect of internal limiting membrane (ILM) peeling on anatomical and functional results in pars plana vitrectomy (PPV) performed eyes with tractional retinal detachment affecting the macula due to diabetes mellitus (DM).

METHODS

Patients without ILM peeling were considered as Group 1, and with ILM peeling were considered as Group 2. The main outcomes were the best-corrected visual acuity (BCVA) at 6 months, and the rate of epiretinal membrane (ERM) formation within 6 months. The rate and the indications for resurgery were determined. Parameters affecting final BCVA were determined by regression analysis.

RESULTS

Final BCVA was significantly better in eyes with ILM-peeled off than in eyes with no peel-off (p=0.012). Less secondary ERM was formed in Group 1 (p=0.009). There was no difference between groups in terms of resurgery rates. (p=0.143). The need for resurgery due to ERM was higher in Group 1 rather than Group 2 (p=0.001). The only factor affecting final BCVA was ILM peeling.

CONCLUSION

In patients with tractional retinal detachment affecting the macula due to diabetes, ILM peeling in addition to PPV and membrane excision does not affect the need for resurgery but contributes positively to anatomical and functional outcomes.

Vitrectomy for Diabetic Complications: A Pooled Analysis of Randomized Controlled Trials Utilizing Modern Techniques and Equipment

PURPOSE

To report updated clinical outcomes in subjects undergoing pars plana vitrectomy (PPV) using modern techniques and equipment for the treatment of proliferative diabetic retinopathy (PDR)-related complications.

DESIGN

Pooled analysis of 5 randomized clinical trials conducted at the same institution and included both study and control subjects from the trials.

METHODS

There were 943 subjects who prospectively underwent small-gauge PPV with anti-vascular endothelial growth factor (VEGF) pretreatment for PDR-related complications and completed 6-months follow up.

RESULTS

The visual acuity of the study population improved from median 2.00 (IQR 1.3, 2.3) at baseline to median 1.00 (IQR 0.5, 1.3) at 6 months. One hundred eighty-four patients (19.5%) achieved 20/50 or better acuity, and 652 patients (69.1%) achieved 20/200 or better acuity at 6 months. The vision improved or remained stable in 901 patients (95.5%), and 11 patients (1.2%) developed no light perception at 6 months. Intraoperative complications occurred in 343 cases (36.4%) of cases, and 199 cases (21.1 %) experienced a postoperative complication. The most common postoperative complication was vitreous hemorrhage in 124 cases (62.3% of all complications). Unplanned secondary PPV was necessary in 86 cases (9.1 %).

CONCLUSIONS

This study reports updated clinical outcomes in patients undergoing PPV for PDR-related complications which compares favorably to the age prior to small-gauge PPV and anti-VEGF pretreatment.

Clinical features and surgical outcomes of complications of proliferative diabetic retinopathy in young adults with type 1 diabetes mellitus versus type 2 diabetes mellitus - A comparative observational study

Purpose:

To evaluate the clinical profile, visual outcomes, and complications among young adult patients with type 1 diabetes mellitus (insulin-dependent DM-T1DM) in comparison with patients with type 2 diabetes mellitus (T2DM) undergoing vitrectomy for complications of proliferative diabetic retinopathy (PDR).

Methods:

A retrospective review of patients between 18 and 45 years with T1DM undergoing vitrectomy for complications of PDR between June 2017 and June 2019, with a minimum follow-up of 12 months. Consecutive patients between 30 and 45 years with type 2 diabetes (non-insulin-dependent DM-T2DM) who underwent vitrectomy for the same indications were retrospectively enrolled as the control group.

Results:

There were 42 eyes (28 patients) in the T1DM group and 58 eyes (47 patients) in the T2DM group. The average age at operation was 35.9 ± 6.88 years and 39.8 ± 3.03 years, respectively (P < 0.001). At the end of follow-up, the mean logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA) improved from 1.53 ± 0.55 to 1.30 ± 0.93 (P value 0.07) in the T1DM group and from 1.59 ± 0.46 to 1.00 ± 0.78 in the T2DM group (P = 0.0001). The rate of the primary and final reattachment was 76.2% and 88.1% in the T1DM group and 84.5% and 96.6% in the T2DM group. Preoperative macular tractional retinal detachment (MTRD) and neovascular glaucoma (NVG) in both the groups, chronic kidney disease (CKD) and lack of preoperative Pan retinal photocoagulation (PRP) in the T1DM group, hypertension (HTN) and, resurgery in the T2DM group, were risk factors for poor vision at the final follow-up.

Conclusion:

The visual and anatomic outcomes were poorer in the T1DM patients which could be due to the longer duration of diabetes with worse glycemic control, associated comorbidities like CKD, and a higher incidence of MTRD.

Intraocular perfluorodecalin and silicone oil tamponade (double filling) in the management of complicated retinal detachment: functional and anatomical outcomes using small-gauge surgery

Purpose

To describe the functional and anatomical results of complicated retinal detachment (RD) treated with small-gauge pars plana vitrectomy (PPV) and combined perfluorodecalin and polydimethylsiloxane tamponade (double filling, DF).

Methods

Retrospective analysis of consecutive patients with complex RD (severe proliferative vitreoretinopathy, inferior/posterior/giant retinal tears, and traumatic detachments) treated with small-gauge PPV, membrane peeling, and DF at the Department of Ophthalmology at San Gerardo Hospital, Monza, Italy. Main outcome measures included best-corrected visual acuity (BCVA), rates of retinal reattachment, and complications.

Results

This study included 15 patients with a median follow-up (FU) of 6 months (range 1–22). Three patients with early retinal redetachment under tamponade and FU shorter than 3 months were excluded from the final functional analysis, but they were considered anatomical failure. At the last examination, BCVA improved in 50% of patients and remained stable in 25% of patients and anatomical success was achieved in 73% of eyes, 64% of them without any endotamponade. Three eyes had retinal redetachment after perfluorodecalin/silicone oil exchange because of diffuse proliferative vitreoretinopathy (PVR) and required reoperation to achieve retinal attachment. In eyes with anatomical success, macular pucker was the most frequent long-term complication (27%).

Conclusion

In the management of complex RD, small-gauge pars plana vitrectomy, and double filling endotamponade using wide-angle viewing systems was a well-tolerated and effective technique to preserve visual acuity and achieve anatomical success.

Management of Complications and Vision Loss from Proliferative Diabetic Retinopathy

PURPOSE OF REVIEW

Diabetes can be associated with profound visual loss due to several mechanisms. As the duration of diabetes and blood glucose levels increase, these changes become more severe. The proliferation of new blood vessels, vitreous hemorrhage, and tractional retinal detachments may ultimately result and can be devastating to visual function. New advances, including anti-vascular endothelial growth factor (VEGF) medications and innovative microsurgical instruments, have provided additional methods for the management of diabetic retinopathy in the clinic and in the operating room, leading to improved outcomes.

RECENT FINDINGS

Advances in earlier treatment of proliferative diabetic retinopathy, especially with anti-VEGF injections, allow for a reduction in severity, improved vision, and more controlled and successful surgery. Modern surgical techniques and instrumentation have also allowed for improved patient outcomes. Future research into sustained delivery and release of anti-VEGF, reducing the need for frequent in-office injections, may prove to be additionally beneficial. Over the last decade, anti-VEGF has become an increasingly common treatment modality for the management of proliferative diabetic retinopathy, vitreous hemorrhages, and tractional retinal detachments. Further research is needed to determine the ideal method of delivery and timing of the treatment.

WIDE-FIELD SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF DIABETIC TRACTIONAL RETINAL DETACHMENTS BEFORE AND AFTER SURGICAL REPAIR

PURPOSE

Wide-field (WF) swept-source (SS) optical coherence tomography angiography (SS-OCTA) was used to image diabetic tractional retinal detachments (TRDs) before and after pars plana vitrectomy. The clinical utility of SS-OCTA was assessed.

METHODS

Patients with diabetic TRDs were imaged prospectively with SS-OCTA. Ultrawide-field imaging was obtained when possible. Postoperative WF SS-OCTA imaging was performed.

RESULTS

From January 2018 through December 2019, 31 eyes of 21 patients with diabetic TRDs were imaged. Wide-field SS-OCTA en-face images captured all areas of TRD and fibrovascular proliferation within the posterior pole that were visualized on ultrawide-field imaging. Optical coherence tomography angiography B-scans revealed the vascularity of preretinal membranes and identified areas of vitreoretinal traction and posterior vitreous detachment. Ten eyes underwent pars plana vitrectomy. Postoperative SS-OCTA imaging demonstrated removal of fibrovascular membranes, relief of traction, and resolution of TRDs. Retinal ischemia before and after surgical repair appeared similar.

CONCLUSION

All clinically relevant features of diabetic TRDs were identified at baseline and assessed longitudinally after pars plana vitrectomy using WF SS-OCTA, which showed resolution of vitreoretinal traction and no apparent change in the status of retinal perfusion after surgery. If the media are clear and fixation is adequate, WF SS-OCTA is likely the only imaging modality needed for the diagnosis and longitudinal evaluation of diabetic TRDs.

Early pars plana vitrectomy for proliferative diabetic retinopathy: update and review of current literature

PURPOSE OF REVIEW

Diabetic retinopathy (DR) is one of the leading causes of preventable vision loss in the world and its prevalence continues to increase worldwide. One of the ultimate and visually impairing complications of DR is proliferative diabetic retinopathy (PDR) and subsequent tractional retinal detachment. Treatment modalities, surgical techniques, and a better understanding of the pathophysiology of DR and PDR continue to change the way we approach the disease. The goal of this review is to provide an update on recent treatment modalities and outcomes of proliferative diabetic retinopathy and its complications including tractional retinal detachment.

RECENT FINDINGS

Panretinal photocoagulation (PRP), anti-vascular endothelial growth factor (anti-VEGF), and pars plana vitrectomy are the mainstay of PDR treatment. However, PRP and anti-VEGF are associated with significant treatment burden and multiple subsequent treatments. Early vitrectomy is associated with vision preservation, less treatment burden, and less subsequent treatments than therapy with PRP and anti-VEGF.

SUMMARY

Concerning costs, high rates of noncompliance in the diabetic population and significant rates of subsequent treatments with initial PRP and anti-VEGF, early vitrectomy for diabetic retinopathy in patients at risk of PDR is a cost-effective long-term stabilizing treatment for diabetics with advanced disease.

DETECTION OF MORPHOLOGIC PATTERNS OF DIABETIC MACULAR EDEMA USING A DEEP LEARNING APPROACH BASED ON OPTICAL COHERENCE TOMOGRAPHY IMAGES

PURPOSE

To develop a deep learning (DL) model to detect morphologic patterns of diabetic macular edema (DME) based on optical coherence tomography (OCT) images.

METHODS

In the training set, 12,365 OCT images were extracted from a public data set and an ophthalmic center. A total of 656 OCT images were extracted from another ophthalmic center for external validation. The presence or absence of three OCT patterns of DME, including diffused retinal thickening, cystoid macular edema, and serous retinal detachment, was labeled with 1 or 0, respectively. A DL model was trained to detect three OCT patterns of DME. The occlusion test was applied for the visualization of the DL model.

RESULTS

Applying 5-fold cross-validation method in internal validation, the area under the receiver operating characteristic curve for the detection of three OCT patterns (i.e., diffused retinal thickening, cystoid macular edema, and serous retinal detachment) was 0.971, 0.974, and 0.994, respectively, with an accuracy of 93.0%, 95.1%, and 98.8%, respectively, a sensitivity of 93.5%, 94.5%, and 96.7%, respectively, and a specificity of 92.3%, 95.6%, and 99.3%, respectively. In external validation, the area under the receiver operating characteristic curve was 0.970, 0.997, and 0.997, respectively, with an accuracy of 90.2%, 95.4%, and 95.9%, respectively, a sensitivity of 80.1%, 93.4%, and 94.9%, respectively, and a specificity of 97.6%, 97.2%, and 96.5%, respectively. The occlusion test showed that the DL model could successfully identify the pathologic regions most critical for detection.

CONCLUSION

Our DL model demonstrated high accuracy and transparency in the detection of OCT patterns of DME. These results emphasized the potential of artificial intelligence in assisting clinical decision-making processes in patients with DME.

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.

Attaining functional levels of visual acuity after vitrectomy for retinal detachment secondary to proliferative diabetic retinopathy

Most patients needing diabetic tractional retinal detachment (TRD) surgery are working-age adults that drive and participate in other vision-dependent activities of daily living. We sought to determine the proportion of patients that achieve functional visual acuity (VA) based on the World Health Organization (WHO) definition of 'low vision' (≤ 20/80) and US driving standards (≥ 20/40) after vitrectomy for diabetic TRD. In this 10-year retrospective review, consecutive patients who underwent primary vitrectomy for TRD from proliferative diabetic retinopathy were studied. 240 eyes in 203 patients met criteria for analysis (38 eyes were lost to follow up at 3 months; 68 at 12 months; 146 at 60 months). While most patients (nearly 80%) having TRD surgery had low vision pre-op, almost half attained VA that was > 20/80 five years post-op. Those most likely to achieve significant visual improvement (p < 0.0001) had concomitant vitreous hemorrhage pre-op. Only 6% of eyes met the US minimum driving standard before surgery based on VA compared to 28% after vitrectomy however this study did not examine visual fields which could warrant additional assessment depending on local requirements. In summary, significant gains in visual acuity are seen after vitrectomy for diabetic TRD that can result in functional improvement in activities of daily living.

Treated PDR Reveals Age-Appropriate Vision Deterioration But Distorted Retinal Organization

Purpose

We determined the progression of visual function, macular structure, and quality of life in patients with regressed proliferative diabetic retinopathy (PDR) after panretinal photocoagulation (PRP).

Methods

In this prospective study, 22 patients who underwent PRP for PDR and 11 age-matched control participants underwent examinations at baseline and after 5 years. Visual acuity, contrast sensitivity, reading acuity, frequency doubling perimetry, Humphrey field analyzer, and dark adaptation were measured. The Low Luminance Questionnaire and National Eye Institute Vision Function Questionnaire-25 were administered. Macular spectral-domain optical coherence tomography was taken.

Results

After 5 years, patients who had previously undergone PRP for PDR (18.4 ± 7.9 years previously) showed significant deterioration in contrast sensitivity, reading acuity, frequency doubling perimetry 24-2 pattern standard deviation, and Humphrey field analyzer 10-2 foveal sensitivity, which were equivalent to age-related decreases in control participants. They revealed no further impairment in vision-related activities on questionnaires. In contrast with controls, their maculas showed pathologic disorganization of the retinal layers, especially the nerve fiber layer, which were thicker and constituted a greater proportion of the overall retinal thickness than the norm and associated with impaired vision.

Conclusions

Patients with treated PDR had age-related decreases in vision, but stable quality of life. Prior injuries from the diabetes and, possibly, laser treatment led to substantial disruption in the retinal structure, which may explain the loss of vision.

Translational Relevance

Despite PRP treatment, patients with regressed PDR had pathologic progression of the nerve fiber layer; further investigation may identify a new therapeutic target to reverse the visual deficits.

Evaluation of Retinal Detachment After Diabetic Vitrectomy: Causes and Ways of Management

Purpose

To assess the causes and the ways of management of rhegmatogenous retinal detachment (RRD) after pars plana vitrectomy (PPV) performed in diabetic patients with advanced diabetic eye disease.

Methods

Retrospective review of the records of the patients who had undergone PPV for complicated proliferative diabetic retinopathy (PDR) was done. Cases with RRD after the PPV were analyzed in the study (n = 32). Preoperative, operative, and postoperative data of the patients were recorded. All patients were recruited for a final follow-up visit.

Results

This retrospective case-control study included 400 eyes of 345 patients. Prolonged surgical duration increased the risk of developing RRD (odds ratio = 1.6342, p = 0.0321). The presence of intraoperative retinal breaks increased the risk of developing postoperative RRD (odds ratio = 2.2308, p = 0.0380). Also, complex diabetic detachment that needed for bimanual dissection of the membranes during surgery were associated with a higher risk of developing postoperative RRD (odds ratio = 2.7311, p = 0.0401).

Conclusion

Rhegmatogenous retinal detachment following diabetic vitrectomy needs a further vitrectomy for the management and usually has poor visual outcome. Prolonged surgical duration, the presence of intraoperative retinal breaks, and the need for bimanual dissection of the membranes (major complex cases) during surgery were associated with higher risk of developing RRD postoperatively.

Internal Limiting Membrane Peeling for Persistent Submacular Fluid after Successful Repair of Diabetic Tractional Retinal Detachment

This study is for reporting the outcomes of internal limiting membrane (ILM) peeling on persistent submacular fluid (PSF) after otherwise successful pars plana vitrectomy (PPV) for diabetic tractional retinal detachment (TRD). In this retrospective case series, five consecutive patients (5 eyes) who exhibited PSF following successful repair of diabetic TRD were included. The second operation was performed to remove ILM. The area of ILM peeling was expanded up to the major vascular arcade. Only air tamponade was used. The median interval between the first PPV and the second PPV with ILM peeling was 4.8 months (range: 4–6 months). PSF resolved completely within one (2 eyes) or 2 months after ILM peeling. The median logMAR best-corrected visual acuity (BCVA) was improved from 1.00 (Snellen equivalent 20/200) to 0.70 (Snellen equivalent 20/100). In conclusion, wide ILM peeling is an effective treatment option for PSF subsequent to successful repair of diabetic TRD. ILM peeling might increase the elasticity of retina, thereby allowing the retina to flatten. This procedure can induce faster retinal reattachment in diabetic TRD involving the macula.

TRActional DIabetic reTInal detachment surgery with co-adjuvant intravitreal dexamethasONe implant: the TRADITION STUDY

AIM

Main failure of diabetic tractional retinal detachment (TRD) surgery is the development of proliferative vitreoretinopathy (PVR), causing higher re-detachment rates. We investigated whether the use of dexamethasone (DEX) implant at the end of pars plana vitrectomy (PPV) with silicone oil tamponade might have an impact on these outcomes.

DESIGN

Comparative, nonrandomized, retrospective study.

PARTICIPANTS

A total of 148 eyes from 148 patients that underwent PPV with silicone oil tamponade for diabetic TRD (with DEX implant, n = 52; without DEX implant, n = 96).

METHODS

Consecutive patients' records were reviewed for time between TRD diagnosis and surgery; lens status before surgery and after 6, 12, and 24 months; retina attachment rate after primary PPV; change in postoperative PVR severity; rate of re-detachment at 6, 12, and 24 months; use of IOP lowering treatment after 6, 12, and 24 months; surgery details; intra- and postoperative complications. Correlations between outcome measures, postoperative PVR severity, and re-detachment rates were analyzed.

MAIN OUTCOME MEASURES

Change in postoperative PVR severity and retinal re-detachment rates with and without the adjuvant use of DEX implant.

RESULTS

Retinal re-detachment rates were significantly higher in the group of patients that did not receive DEX implant [11/96 (11.5%) vs. 0/52 (0%), p = 0.049; 11/84 (12.9%) vs. 4/52 (7.7%), p = 0.007; 14/71 (19.7%) vs. 5/52 (10%) p < 0.001 at 6, 12, and 24 months, respectively]. PVR severity correlated with retinal status at 12 and 24 months (p = 0.018 and p = 0.027, respectively). The difference in PVR severity between the two groups was statistically significant at 6, 12, and 24 months (p < 0.001).

CONCLUSIONS

DEX implant at the end of PPV in patients with diabetic TRD improves PVR severity and decreases re-detachment rates. This should be considered as an option in the customized treatment of TRD.

Outcomes of vitrectomy for diabetic tractional retinal detachment in Chicago's county health system

PURPOSE

To examine outcomes of 23-gauge (23G) pars plana vitrectomy (PPV) for complex diabetic tractional retinal detachment (TRD) in Chicago's Cook County Health and Hospitals System (CCHHS).

MATERIALS AND METHODS

This is a retrospective noncomparative study of diabetic TRD cases that underwent PPV at CCHHS. Primary retinal reattachment rate, visual function, and postoperative complications were analyzed.

RESULTS

Sixty nine consecutive cases were included. Primary reattachment and final attachment were achieved in 68/69 eyes (98.6%). Secondary retinal detachment was noted in 1 eye (1.4%). Vitreous hemorrhage requiring repeat PPV developed in 5 eyes (7.2%) and reoperation due to other complications was required in 4/69 eyes (5.8%). Perfluoropropane (C3F8) gas tamponade was used in 91.3% of eyes and silicone oil in 8.7% of eyes. Mean LogMAR visual acuity significantly improved from 1.84 ± 0.61 to 0.93 ± 0.66, (P<0.0001). Vision was stabilized or improved in 66 eyes (95.7%). Visual acuity of 20/200 or better was achieved in 49/69 eyes (71.0%) and 20/50 or better in 16/69 eyes (23.2%).

CONCLUSIONS

Even in patients with severe and advanced diabetic TRD pathology and unique demographics as seen in CCHHS, modern vitrectomy techniques can provide excellent anatomical and visual outcomes.

Surgical management of diabetic tractional retinal detachments

Tractional retinal detachment is an end-stage form of diabetic retinopathy that occurs when contractile forces in the vitreous and neovascular tissue lead to the detachment of the neurosensory retina. We review the literature related to the management of this disease. Preoperative planning includes appropriate patient selection, diagnostic and prognostic imaging, and medical optimization with reduction of systemic risk factors. Use of antivascular endothelial growth factor for preoperative treatment has had significant benefits for tractional retinal detachment repair in improving surgical efficiency and outcomes. Advances in microsurgical instrumentation are discussed, with attention to small-gauge vitrectomy with improved flow dynamics, viewing strategies, and lighting allowing bimanual surgery. Special emphasis is placed on bimanual surgical technique, choice of tamponade, and the avoidance of iatrogenic damage. Complications and special considerations are further explored. Based on our compilation of relevant literature, we propose a surgical algorithm for the management of these complex patients.

Current management of diabetic tractional retinal detachments

Twenty-five percent of diabetes-related vision loss stems from complications of proliferative diabetic retinopathy (PDR). Panretinal photocoagulation has been the preferred treatment of high-risk PDR for decades and more recently intravitreal injections of drugs that inhibit the actions of vascular endothelial growth factor have become popular. But despite these treatments PDR may progress uncontrollably to advanced pathologies such as traction retinal detachments (TRDs), combined traction/rhegmatogenous retinal detachments (TRD/RRDs), vitreous hemorrhages, rubeosis iridis, and traction maculopathies, which produce mild-to-severe loss of vision. TDR have long been the most common indication for PDR-related vitreoretinal surgery. Vitrectomy surgery is indicated for recent (<6 months duration) TRD involving the macula, progressive TRD that threatens the macula, and recent data suggest that chronic macula-involving TRDs (>6 months duration) may also benefit. Combined TRD/RRD represents a particularly challenging surgical condition but advances in surgical instrumentation, dissection techniques, and post-operative tamponade have produced excellent success rates. The recent development of small-gauge vitrectomy systems has persuaded most surgeons to switch platforms since these appear to produce shorter surgical times and quicker post-operative recoveries. Pre-operative injections of bevacizumab are frequently administered for persistent neovascularization to facilitate surgical dissection of pre-retinal fibrosis and reduce the incidence of post-operative hemorrhages. Recent trends toward earlier surgical intervention and expanded indications are likely to continue as surgical instrumentation and techniques are further developed.