Severe Proliferative Diabetic Retinopathy Research Articles

Classification Features of Severe Stages of Proliferative Diabetic Retinopathy (Clinical Cases)

Purpose: analysis of clinical cases illustrating the classification features of severe stages of proliferative diabetic retinopathy (PDR).Patient and methods. Three clinical cases of PDR are presented, in which ophthalmoscopic signs (according to the classification of the Early Treatment Diabetic Retinopathy Study, 1991) corresponded to severe PDR (high risk 1, high risk 2) and advanced PDR. The ophthalmological status was assessed using standard methods based on measuring the best corrected distance visual acuity, performing ultrasound (Opticon 2000, Italy), photographic recording of the condition of the fundus (Carl Zeiss Visucam 500, Germany) and optical coherence tomography of the macular region (on an RTVue-100 tomograph, OptoVue, USA).Results and conclusion. The presented clinical examples will provide the ophthalmologist with a more complete understanding of the clinical picture of pathological changes in the retina in diabetes mellitus, which will ultimately increase the level of diagnosis and tactics of surgical intervention both during the initial (preoperative) examination and after vitrectomy.

Sight threatening diabetic retinopathy in patients with macular telangiectasia type 2

PurposeAlthough diabetes is highly prevalent in patients with macular telangiectasia type 2 (MacTel), progression to severe non-proliferative (NPDR) and proliferative diabetic retinopathy (PDR) is rarely reported. We report multimodal imaging features of sight-threatening diabetic retinopathy (STDR) in eyes with MacTel.MethodsRetrospective case series of seven participants of the MacTel Study at the Moorfields Eye Hospital NHS Foundation Trust study site and one patient from the Institute of Retina and Vitreous of Londrina, Brazil. Sight threatening diabetic retinopathy was defined as severe NPDR, PDR or diabetic macular edema.ResultsWe report imaging features of 16 eyes of eight patients (7/8, 87.5% female) with diagnoses of MacTel and type 2 diabetes mellitus with STDR. Mean (SD) age was 56 (8.3) years. Patients were followed-up for a mean time of 9.1 (4.7) years. A total of 10/16 (62.5%) eyes showed PDR and 2/16 (12.5%) eyes presented a macular epiretinal neovascularization.ConclusionsPeople with diabetes mellitus and MacTel may not be protected from STDR as previously reported. Although the two diseases rarely co-exist, regular monitoring for diabetic retinopathy progression is recommended according to baseline retinopathy severity grades in line with established international guidelines. The presence of MacTel may not modify extended screening intervals, but there is no current evidence. The limited case series in the literature support treatment for complications and should follow the standard of care for either condition. Due to dual pathology, reactivation may be difficult to diagnose on standard imaging and multimodal imaging is recommended.

Comparison of Widefield OCT Angiography Features Between Severe Non-Proliferative and Proliferative Diabetic Retinopathy.

There is a high and ever-increasing global prevalence of diabetic retinopathy (DR) and invasive imaging techniques are often required to confirm the presence of proliferative disease. The aim of this study was to explore the images of a rapid and non-invasive technique, widefield optical coherence tomography angiography (OCT-A), to study differences between patients with severe non-proliferative and proliferative DR (PDR). We conducted an observational longitudinal study from November 2022 to March 2023. We recruited 75 patients who were classified into a proliferative group (28 patients) and severe non-proliferative group (47 patients). Classification was done by specialist clinicians who had full access to any multimodal imaging they required to be confident of their diagnosis, including fluorescein angiography. For all patients, we performed single-shot 4 × 4 and 10 × 10mm (widefield) OCT-A imaging and when possible, the multiple images required for mosaic 17.5 × 17.5mm (ultra widefield) OCT-A imaging. We assessed the frequency with which proliferative disease was identifiable solely from these OCT-A images and used custom-built MATLAB software to analyze the images and determine computerized metrics such as density and intensity of vessels, foveal avascular zone, and ischemic areas. On clinically assessing the OCT-A 10 × 10 fields, we were only able to detect new vessels in 25% of known proliferative images. Using ultra-widefield mosaic images, however, we were able to detect new vessels in 100% of PDR patients. The image analysis metrics of 4 × 4 and 10 × 10mm images did not show any significant differences between the two clinical groups. For mosaics, however, there were significant differences in the capillary density in patients with PDR compared to severe non-PDR (9.1% ± 1.9 in the PDR group versus 11.0% ± 1.9 for severe group). We also found with mosaics a significant difference in the metrics of ischemic areas; average area of ischemic zones (253,930.1 ± 108,636 for the proliferative group versus 149,104.2 ± 55,101.8 for the severe group. Our study showed a high sensitivity for detecting PDR using only ultra-widefield mosaic OCT-A imaging, compared to multimodal including fluorescein angiography imaging. It also suggests that image analysis of aspects such as ischemia levels may be useful in identifying higher risk groups as a warning sign for future conversion to neovascularization.

The effect of hypothyroidism on the risk of diabetes and its microvascular complications: a Mendelian randomization study.

Several observational studies have found that hypothyroidism is associated with diabetes and its microvascular complications. However, the cause and effect have not been clarified. The aim of the study was to examine the causality of such associations by a Mendelian randomization study. Two-sample Mendelian randomization analysis was conducted to investigate the associations. Summary statistics for hypothyroidism were from the UK Biobank, and diabetes and its microvascular complications were from the largest available genome-wide association studies. MR-Egger, weighted median, inverse variance weighted, simple mode and weighted mode were used to examine the causal associations, and several sensitivity analyses were used to assess pleiotropy. Inverse variance weighted estimates suggested that hypothyroidism was associated with type 1 diabetes and type 1 diabetes with renal complications (β= 9.059926, se= 1.762903, P = 2.76E-07 and β= 10.18375, se= 2.021879, P = 4.73E-07, respectively) but not type 2 diabetes and type 2 diabetes with renal complications. In addition, hypothyroidism was positively associated with severe nonproliferative diabetic retinopathy and proliferative diabetic retinopathy (β= 8.427943, se= 2.142493, P = 8.36E-05 and β= 3.100939, se= 0.74956, P=3.52E-05, respectively). The study identified the causal roles of hypothyroidism in diabetes and its microvascular complications. Hypothyroidism can lead to type 1 diabetes, type 1 diabetes with renal complications, severe nonproliferative diabetic retinopathy and proliferative diabetic retinopathy.

A broad study of machine learning and deep learning techniques for diabetic retinopathy based on feature extraction, detection and classification

Diabetic Retinopathy (DR) is a micro vasculardisorder that affects the eyes and is a long term effectofDiabetesmellitus. The likelihood to develop diabetic retinopathy is directly proportional to the age and duration of the diabetes, as well as increase in the level of blood glucose level and fluctuation in blood pressure levels. A person who has diabetes has more probability to develop diabetic retinopathy. The ration of people with diabetes started to increase from 285 million in 2010 and will reach up to 439 million in the year of 2030.Out of the total number of people with Diabetic Retinopathy, approximately one-fourth of the people have vision-threatening disease. Earlier detection and classificationof Diabetic Retinopathy has to be taken much care in order to sustain a patient’s vision. The diabetic Retinopathy may be classified into various stages like Mild non-proliferative retinopathy, Moderate nonproliferative retinopathy, severe nonproliferative Retinopathy and Proliferative diabetic retinopathy. Theproblem associated with the manual detection of diabetic retinopathy is that the processing time is high, effortconsumingandrequiresanophthalmologist to examine the eye retinal fund us images. The manual analysis includes Visual Acuity testing, Tonometry and Pupil dilation. The vision lost due to Diabetic retinopathy is sometimes irreparable. Hence there is a need for earlier detection and treatment to reduce the risk of blindness.Hence there are various automated methods of diabetic retinopathy screening that have made good progress using image classification, pattern recognition, and machine learning. The input to the automated image classification model can be the color fundus photography or optical Coherence tomography images.

An effective and comprehensible method to detect and evaluate retinal damage due to diabetes complications.

The leading cause of vision loss globally is diabetic retinopathy. Researchers are making great efforts to automatically detect and diagnose correctly diabetic retinopathy. Diabetic retinopathy includes five stages: no diabetic retinopathy, mild diabetic retinopathy, moderate diabetic retinopathy, severe diabetic retinopathy and proliferative diabetic retinopathy. Recent studies have offered several multi-tasking deep learning models to detect and assess the level of diabetic retinopathy. However, the explanation for the assessment of disease severity of these models is limited, and only stops at showing lesions through images. These studies have not explained on what basis the appraisal of disease severity is based. In this article, we present a system for assessing and interpreting the five stages of diabetic retinopathy. The proposed system is built from internal models including a deep learning model that detects lesions and an explanatory model that assesses disease stage. The deep learning model that detects lesions uses the Mask R-CNN deep learning network to specify the location and shape of the lesion and classify the lesion types. This model is a combination of two networks: one used to detect hemorrhagic and exudative lesions, and one used to detect vascular lesions like aneurysm and proliferation. The explanatory model appraises disease severity based on the severity of each type of lesion and the association between types. The severity of the disease will be decided by the model based on the number of lesions, the density and the area of the lesions. The experimental results on real-world datasets show that our proposed method achieves high accuracy of assessing five stages of diabetic retinopathy comparable to existing state-of-the-art methods and is capable of explaining the causes of disease severity.

Is There a Nonperfusion Threshold on OCT Angiography Associated With New Vessels Detected on Ultra-Wide-Field Imaging in Diabetic Retinopathy?

To determine whether the nonperfusion index (NPI) measured on widefield (WF) optical coherence tomography angiography (OCTA) could be used as an alternative method for the diagnosis of proliferative diabetic retinopathy (PDR) and to study the relationship between the NPI and the location of new vessels (NV) in eyes with PDR. Fifty-one treatment-naïve eyes with either severe nonproliferative DR (NPDR) or PDR were imaged using ultra-wide-field imaging and wide-field OCTA. The NPI was significantly higher in eyes with PDR (18.94% vs. 7.51%; P < 0.01). Using the NPI on the whole image to assess PDR status, the area under the curve was 0.770, but the area under the curve increased when the NPI of the most peripheral circle was used (area under the curve of 0.792). Four eyes with PDR (17%) had NV outside the OCTA image field, and their mean NPI (6.15 %) did not differ from that measured in severe NPDR eyes (7.51%; P = 0.67) and was lower than in other eyes with PDR (21.49%; P = 0.023). The presence of NV in a sector was associated with a higher NPI in the same sector (29.2% vs. 6.0%; P < 10-15). Although the NPI was significantly higher in eyes with PDR compared with severe NPDR eyes, its measurement on the whole wide-field OCTA image was not sensitive enough to replace the detection of NV for the diagnosis of PDR. Because the presence of new vessels was related to the local nonperfusion index in the same sector, the assessment of nonperfusion outside the optical coherence tomography angiography field is important in diabetic retinopathy.

Combined Use of Anti-VEGF Drugs Before and During Pars Plana Vitrectomy for Severe Proliferative Diabetic Retinopathy.

This study aimed to evaluate the combined administration of anti-vascular endothelial growth factor (anti-VEGF) drugs before and during pars plana vitrectomy (PPV) and to explore its efficacy and safety in the treatment of patients with severe proliferative diabetic retinopathy (PDR). This retrospective case series included consecutive patients who underwent PPV. Patients were categorized into two groups: the preoperative group was injected with anti-VEGF drugs before PPV, and the combination group was injected with anti-VEGF drugs before and during PPV. Preoperative, intraoperative, and postoperative clinical data were collected for analysis. The main outcome measures were changes in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) and occurrence of postoperative vitreous cavity haemorrhage (POVCH). In total, 63 eyes of 60 patients with severe PDR were analysed. The operative duration and occurrence of intraoperative haemorrhage, iatrogenic retinal breaks, and silicone oil tamponade were similar between the two groups. The benefits on BCVA, and CRT after 1week postoperatively, were more obvious in the combination group (P < 0.01). Combination therapy had the potential to reduce the incidence of POVCH. No ocular or systemic adverse events occurred in either group. The combined use of anti-VEGF drugs before and during PPV in patients with severe PDR not only includes the advantages of preoperative injection, but also has more significant prognostic benefits and favourable safety profiles.

Risk Factors and Outcomes of Delayed Presentation of Diabetic Retinopathy Patients to a County Hospital.

To identify risk factors and evaluate outcomes of patients with delayed presentation and advanced diabetic retinopathy in our safety-net county hospital population. A retrospective study was performed on 562 patients who presented with a new diagnosis of diabetic retinopathy (DR). Delayed presentation was defined as moderate or severe nonproliferative diabetic retinopathy (NPDR) or proliferative diabetic retinopathy (PDR) at the initial visit. Comparisons between patient groups were performed with chi-square or Fisher's exact test for categorical variables and multinomial logistic regression for multivariable analysis. Linear and logistic regression modeling with general estimating equations to account for patients having two eyes was used to compare eye-level outcomes. Lack of a primary care provider (PCP) was highest in patients who presented initially with PDR (28.8%), compared to 14.3% in moderate/severe NPDR, 12.4% in mild NPDR, and 7.6% in no DR groups (P < 0.001). Only 69.4% of patients with a PCP had an ophthalmology screening referral. Highest lack of referral (47.2%) was seen in the PDR group (P = 0.002). Patients with PDR were more likely to be uninsured (19.2%) compared to no and mild DR groups, with rates of 7.6% and 9.0%, respectively (P = 0.001). The PDR group had worse initial and final visual acuities (P < 0.001). Several risk factors were noted for delayed DR presentation, including lack of PCP, lack of screening referral, and uninsured/underinsured status. Patients with advanced DR at presentation had worse final visual outcomes despite aggressive treatment. Screening programs targeting populations with identified risk factors are essential for improving outcomes.

A Feasibility Study of Diabetic Retinopathy Detection in Type II Diabetic Patients Based on Explainable Artificial Intelligence.

Diabetic retinopathy (DR) is vision impairment and a life-threatening condition for diabetic patients. Especially type II diabetic people have higher chances of getting retinal problems. Hence, early prediction of DR is necessary for preventing the diabetic patients from vision impairment. The main aim of this feasibility study is to identify the most critical risk features that could lead to diabetic retinopathy. This study investigated type II diabetic patients' socio-analytical, diabetes, behavioral, and clinical risk factors. We conducted a self-individual questionnaire session for all participants. Our questionnaire asked about the reliability of results, feeling comfortable during the screening test, willingness to participate in future screenings, overall perspective, and satisfaction with the DR screening test. We proposed a random forest model for predicting the prevalence of DR risk among diabetics. Further explanations of the model were conducted using more robust SHAP eXplainable Artificial Intelligence (XAI) tools. The SHAP method makes it possible to understand how input variables interact with their representative output records, as well as how input variables are ranked. In addition, various descriptive and inferential statistical analyses were performed on the data and evaluated the significant relationship between the factors discussed above via hypothesis testing. This feasibility study involved 172 type II diabetic patients (73 males and 99 females). Therefore, we found that 81 (47.09%) out of 172 participants had referable DR. The average age of the patients was determined as 55.08, with a standard deviation of ± 9.770 (ranging from 40 to 79). Type II patients were affected by mild, moderate, severe, and advanced proliferative diabetic retinopathy (PDR) stages with 23.83%, 13.95%, 5.81%, and 3.48%, respectively, of the total samples. The developed RF model obtained high accuracy of 94.9% using clinical dataset. Our results showed that the formation of tiny microminiature lesions was noticeable in type II diabetic patients with aged people, abnormal blood glucose levels, and prolonged diabetes duration.

Association of Diabetic Lesions and Retinal Nonperfusion Using Widefield Multimodal Imaging

To evaluate the association of microvascular lesions on ultrawidefield (UWF) color fundus (CF) images with retinal nonperfusion (RNP) up to the midperiphery on single-capture widefield (WF) OCT angiography (OCTA) in patients with diabetic retinopathy (DR). Cross-sectional study. Seventy-five eyes of 50 patients with mild to severe nonproliferative DR (NPDR) and proliferative DR (PDR) were included in this analysis. ETDRS level and presence of predominantly peripheral lesions (PPLs) were assessed on UWF-CF images acquired with a Zeiss Clarus 700. Single-capture 65°-WF-OCTA was performed using a PlexElite prototype (Carl Zeiss Meditec, Inc.). A custom grid consisting of a central ETDRS grid extended by 2 rings reaching up to the midperiphery was overlaid to subdivide retinal areas visible on WF-OCTA en face images. Retinal nonperfusion was measured in each area and in total. Nonperfusion index (NPI) was calculated from total RNP. On UWF-CF images, the number of microaneurysms, hemorrhages, neovascularizations, and areas with intraretinal microvascular abnormalities (IRMAs) were evaluated using the same grid. Association of diabetic lesions with RNP was calculated using Spearman correlations (rs). Median RNP on WF-OCTA was 0 mm2 (0-0.9), 4.9 mm2 (1.9-5.4), 23.4 mm2 (17.8-37), and 68.4 mm2 (40.8-91.7) in mild, moderate, and severe NPDR and PDR, respectively. We found a statistically significant correlation (P < 0.01) of overall RNP (rs= 0.96,) and NPI (rs= 0.97) on WF-OCTA with ETDRS level. Number of grid-fields affected by IRMAs on CF images was highly associated with NPI (rs= 0.86, P < 0.01). Intraretinal microvascular abnormalities and RNPs had similar topographic distributions with high correlations in affected areas. Eyes with PPLs (n= 43 eyes, 57%) on CF images had a significantly higher NPI (P= 0.014) than eyes without PPLs. The combination of UWF-CF imaging and single-capture WF-OCTA allows precise and noninvasive analysis of the retinal vasculature up to the midperiphery in patients with DR. The presence and extent of IRMAs on CF images may serve as an indicator for underlying RNP, which is more pronounced in eyes with PPLs. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Inter-Rater Reliability of Proliferative Diabetic Retinopathy Assessment on Wide-Field OCT-Angiography and Fluorescein Angiography.

To assess inter-rater reliability in the detection of proliferative diabetic retinopathy (PDR) changes using wide-field optical coherence tomography angiography (WF-OCTA) versus fluorescein angiography (FA). This retrospective, cross-sectional study included patients with severe nonproliferative and PDR. Images were acquired with 12 × 12 mm WF-OCTA and FA with a 55° lens. Images were cropped to represent the exact same field of view. Qualitative (detection of neovascularization at the disc [NVD] and elsewhere [NVE], enlarged foveal avascular zone [FAZ], vitreous hemorrhage [VH]) and quantitative analyses (FAZ area, horizontal, vertical, and maximum FAZ diameter) were performed by 2 masked graders using ImageJ. Inter-rater reliability was calculated using unweighted Cohen's kappa coefficient (κ) for qualitative analyses and intraclass correlation coefficients (ICC) for quantitative analyses. Twenty-three eyes of 17 patients were included. Inter-rater reliability was higher for FA than for WF-OCTA in qualitative analyses: κ values were 0.65 and 0.78 for detection of extended FAZ, 0.83 and 1.0 for NVD, 0.78 and 1.0 for NVE, and 0.19 and 1 for VH for WF-OCTA and FA, respectively. In contrast, inter-rater reliability was higher for WF-OCTA than for FA in the quantitative analyses: ICC values were 0.94 and 0.76 for FAZ size, 0.92 and 0.79 for horizontal FAZ diameter, 0.82 and 0.72 for vertical FAZ diameter, and 0.88 and 0.82 for maximum FAZ diameter on WF-OCTA and FA, respectively. Inter-rater reliability of FA is superior to WF-OCTA for qualitative analyses whereas inter-rater reliability of WF-OCTA is superior to FA for quantitative analyses. The study highlights the specific merits of both imaging modalities in terms of reliability. FA should be preferred for qualitative parameters, whereas WF-OCTA should be preferred for quantitative parameters.

Proliferative Diabetic Retinopathy Requiring Vitrectomy Over Clinic Management During COVID-19: Impact of Delayed Care.

This study aimed to investigate the impact of delayed retinal clinical care during the COVID-19 pandemic on the severity of proliferative diabetic retinopathy (PDR) and drivers of follow-up delay. We compared disease severity and follow-up rates of PDR patients requiring vitrectomy to those managed nonsurgically, and identified factors associated with need for vitrectomy. The study included 739 patients diagnosed with PDR between January 1, 2018, and March 4, 2021, categorized into two groups based on outcome: vitrectomy nonvitrectomy. Statistical methods such as t-tests and chi-square tests were used to analyze differences in disease severity and follow-up rates before and after COVID-19 shutdown. A multivariate regression evaluated factors leading to vitrectomy by comparing initial ETDRS (Early Treatment of Diabetic Retinopathy Study) DR staging, disease stability, DR progression, proliferative complications, appointment intervals, follow-up variance, rescheduling rate, and no-show rate. Of the 739 patients, 202 required vitrectomy, 537 were managed nonsurgically. The vitrectomy group had more severe or unstable disease before shutdown. The interval between patient visits preshutdown was 29.76 ± 45.11 days in the vitrectomy group and 40.23 ± 56.73 days in the nonvitrectomy group (p &lt; 0.001). Both groups experienced a significant increase in appointment intervals after shutdown, with the vitrectomy group having a greater increase. Both groups had significantly increased rescheduling rate and minimally increased no-show rate. Patient-directed rescheduling was the main driver of appointment delays. Disease factors, such as tractional retinal detachment and higher ETDRS DR staging, increased the odds of vitrectomy, while appointment burden and follow-up variability had a minimal impact. Patients with more severe PDR and greater delay in appointments due to the pandemic were more likely to require vitrectomy for proliferative complications. Patient-directed rescheduling was identified as the main driver of care delays, as opposed to clinic-directed rescheduling. This study highlights the importance of maintaining regular follow-up appointments for PDR patients during pandemics.

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

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

Quantification of macular perfusion following panretinal photocoagulation for diabetic retinopathy: An optical coherence tomography angiography study.

To assess the effects of panretinal photocoagulation (PRP) on the microvascular structure of the macula and central thickness of the macula and choroid via optical coherence tomography angiography (OCTA). In this prospective clinical study, 43 eyes of 31 patients with severe non-proliferative diabetic retinopathy or early proliferative diabetic retinopathy were included. Before and at the third and sixth months after PRP, the foveal avascular zone (FAZ) area, acircularity index (AI), foveal density (FD), and vascular density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were evaluated using OCTA. The central macular thickness (CMT) and subfoveal choroidal thickness (SCT) were also measured after PRP. There was no difference between the FAZ area, AI, FD, and vessel density of the SCP and DCP before and at the third and sixth months after PRP (all p>0.05). The CMT value was higher at the third and sixth months than at baseline (p=0.002 and p=0.001, respectively). The SCT value was lower at the third and sixth months than at baseline (p=0.002 and p=0.001, respectively). PRP is a beneficial and reliable method that supports the integrity of the macular microvascular structure. After PRP, the CMT increases, and the SCT decreases.

Evaluating the Effect of Hypoglycemic Agents on Diabetic Retinopathy Progression

Newer hypoglycemics such as dipeptidyl peptidase 4 (DPP-4) inhibitors, sodium-glucose cotransporter-2 (SGLT-2) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists have been increasingly used in diabetes. This study aimed to assess the relationship between usage of these hypoglycemic agents and effect on diabetic retinopathy (DR). Using the Vestrum Health Retina Database, patients with DR with 1 year follow-up after use of a hypoglycemic agent were included and stratified by agent, including no pharmacotherapy. Of 60,649 eyes, in 1 year after hypoglycemic agent usage, progression rates from severe nonproliferative diabetic retinopathy (NPDR) to proliferative diabetic retinopathy (PDR) were the following: DPP-4 (17%), SGLT-2 (12%), GLP-1 (21%), metformin (18%), and none (20%). Progression rates from moderate NPDR to severe NPDR or PDR were the following: DPP-4 (11%), SGLT-2 (10%), GLP-1 (11%), metformin (10%), none (13%). Progression rates from mild NPDR to moderate/severe NPDR or PDR were the following: DPP-4 (6%), SGLT-2 (9%), GLP-1 (9%), metformin (7%), and none (10%). Within a large real-world database, patients prescribed GLP-1 agonists were found to have DR progression rates comparable to those of patients receiving no hypoglycemic agents. [Ophthalmic Surg Lasers Imaging Retina 2023; 54(3):158-165.].

Effect of Adjunctive Intravitreal Conbercept Injection at the End of 25G Vitrectomy on Severe Proliferative Diabetic Retinopathy: 6-Month Outcomes of a Randomised Controlled Trial.

This study aimed to evaluate the effect of pre-operative versus pre-operative plus post-operative intravitreal conbercept (IVC) injection on severe proliferative diabetic retinopathy (PDR). This was a prospective, comparative and randomised study. A total of 84 patients who underwent vitrectomy for severe PDR were included in this study. Patients were randomly divided into control (41 eyes) and experiment (43 eyes) groups. Patients in the experiment group received adjunctive pre-operative and post-operative IVC injection, whereas patients in the control group only received pre-operative IVC injection. The incidence of post-operative vitreous haemorrhage (POVH), best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were determined. The incidence of early POVH was significantly different between the two groups, but no significant difference was observed between groups at 3 and 6months. In the experiment group, the BCVA was significantly improved 1month after surgery when compared with the control group (p 0.019). There was no marked difference in the mean post-operative BCVA at 3 and 6months between groups (p 0.063 and 0.082). CRT was significantly lower in the experiment group than in the control group at 1 and 3months after surgery (p 0.037 and 0.041), but there was no significant difference at 6months (p 0.894). Additional IVC injected at the end of surgery improves the POVH and BCVA at the early stage after surgery in severe PDR, but this benefit is absent at 6months. Further studies are needed to investigate the effect of IVC at the end of vitrectomy. chictr.org.cn identifier: ChiCTR2200060735. Retrospectively registered, register date: 9 June 2022.

Comparison of Chorioretinal Parameters in Diabetic Retinopathy with or without Pan-Retinal Photocoagulation Using Ultrawide-Field Swept-Source Optical Coherence Tomography Angiography

Introduction: To compare structural and vascular parameters in the central and peripheral retina and choroid of eyes diagnosed with severe nonproliferative diabetic retinopathy (NPDR) or proliferative diabetic retinopathy (PDR) with or without pan-retinal photocoagulation (PRP) using ultrawide-field swept-source optical coherence tomography angiography (SS-OCTA). Methods: All participants underwent SS-OCTA imaging centered on the fovea. Retinal and choroidal thickness, vessel density of the superficial capillary plexus (SCP), deep capillary plexus (DCP), choroidal capillary plexus (CCP), and choroidal Sattler’s and Haller’s layer (CSHL) were analyzed in nine grids using built-in angiography analysis software. Results: A total of 82 eyes from 82 participants were enrolled in this study, including 40 eyes diagnosed with severe NPDR or PDR without PRP and 42 eyes with PRP. Retinal thickness in part grids was higher in eyes with PRP than in eyes without PRP. Vessel density of the SCP in nasal-superior (p = 0.003) grid was lower in eyes with PRP than in eyes without PRP. No significant difference was found in the vessel density of the DCP between the two groups (all p > 0.05). The choroidal thickness and vessel density of the CSHL of all grids were significantly lower in eyes with PRP than in eyes without PRP (all p p = 0.043), nasal-superior grid (p = 0.003), macular grid (p p = 0.001) of eyes with PRP, compared to eyes without PRP. A significant decrease in the vessel density of CSHL was observed in all grids of PDR eyes with PRP compared to PDR eyes without PRP (all p p = 0.090) and optic disc grid (p = 0.057). Conclusion: Structural and vascular parameters in the central and peripheral retinal and choroidal layers in eyes diagnosed with severe NPDR or PDR with or without PRP could be quantified using a ultrawide-field SS-OCTA. Eyes with PRP showed a significant decrease in choroidal thickness and vessel density of CCP and CSHL, compared with eyes without PRP. This trend was more obvious in eyes with PDR.

OCT Angiography Features in Diabetes Mellitus Type 1 and 2.

Purpose: To study the foveal avascular zone (FAZ) and the vessel densities (VD) in diabetic patients using optical coherence tomography angiography (OCT-A) and inner retinal layer changes to compare patients affected by type 1 diabetes (DM1) and type 2 diabetes (DM2). Methods: Cross-sectional observational study involving 150 eyes of 150 patients with DM1, and 155 eyes of 155 patients with DM2 with diabetic retinopathy (DR). Retinal nerve fiber layer (RNFL) and Ganglion cell layer (GCL) were evaluated. OCT-A studied both FAZ and VD at the level of the superficial capillary plexus (SCP) and the deep capillary plexus (DCP). Results: A statistically significant difference in FAZ area and foveal VD measured at the SCP (p &lt; 0.001) was noted between DM1 and DM2 groups when comparing patients with mild and moderate non-proliferative diabetic retinopathy (NPDR), while no differences were found in the severe NPDR and proliferative diabetic retinopathy (PDR) subgroups. Duration of diabetes and stage of DR were directly correlated with enlargement of FAZ area and inversely correlated with foveal VD measured at SCP. RNFL and GCL were not different between DM1 and DM2 groups. Conclusion: Changes in OCT-A parameters detected in FAZ area and VD of diabetic patients with different stages of DR may help to predict the risk for progression of the disease.

MORPHOLOGICAL ASSESSMENT OF DIABETIC RETINOPATHY

A morphological study of the thickness of the choroid in patients with diabetes using spectral- domain optical coherence tomography was carried out in order to analyze the morphological changes of choroidal vessels and their role in the mechanism of diabetic retinopathy, which was carried out on the eyes of 203 participants with diabetes and on the eyes of 48 we are healthy people. The thickness of the choroid in the area of the foveal lesion was measured using optical coherence tomography with enhanced imaging. Participants were grouped according to the degree of diabetic retinopathy: no diabetic changes, mild or moderate, or severe nonproliferative or proliferative diabetic retinopathy. Study parameters included history, age, axial length, intraocular pressure, central retinal thickness, fasting glucose, and blood pressure. As a result, subfoveal choroidal thickness was smaller in eyes with nonproliferative or proliferative diabetic retinopathy than in normal eyes (p &lt;0.01). However, there was no diff erence between eyes with nonproliferative and proliferative diabetic retinopathy or between eyes without diabetic changes and controls. Eyes with macular edema did not show a signifi cant diff erence in choroidal thickness compared to eyes with normal macular contours. Consequently, the central choroid thins when eyes exhibit diabetic retinal changes. However, the presence of diabetic macular edema or proliferative changes was not associated with more pronounced choroidal thinning.