Association between Neurodegeneration and Macular Perfusion in the Progression of Diabetic Retinopathy: A 3-Year Longitudinal Study.

OBJECTIVE AND PURPOSE: The aim of this study was to explore the relation between retinal neurodegenerative changes and vessel closure (VC) in individuals with nonproliferative diabetic retinopathy (NPDR) in a follow-up period of 3 years. DESIGN: This is a 3-year prospective longitudinal study with four annual visits. PARTICIPANTS: This study involved 74 individuals with type 2 diabetes, NPDR, and Early Treatment Diabetic Retinopathy Study grades from 10 to 47, one eye/person. An age-matched healthy control population of 84 eyes was used as control group. METHODS: Participants were annually examined by color fundus photography, spectral domain-optical coherence tomography (SD-OCT) and OCT-angiography (OCTA). VC was assessed by OCTA vessel density maps. SD-OCT segmentations were performed to access central retinal thickness (CRT) and retinal neurodegeneration considered as thinning of the ganglion cell plus inner plexiform layer (GCL + IPL). RESULTS: Type 2 diabetic individuals presented significantly higher CRT (p = 0.001), GCL + IPL thinning (p = 0.042), and decreased vessel density at the superficial capillary plexus (p < 0.001) and full retina (FR) (p = 0.001). When looking at changes occurring over the 3-year period of follow-up (Table 2), there were statistically significant decreases in GCL + IPL thickness (-0.438 µm/year; p = 0.038), foveal avascular zone circularity (-0.009; p = 0.047), and vessel density in superficial capillary plexus (-0.172 mm-1/year; p < 0.001), deep capillary plexus (DCP) (-0.350 mm-1/year; p < 0.001), and FR (-0.182 mm-1/year; p < 0.001). A statistically significant association was identified between GCL + IPL thinning and decrease in DCP vessel density (ß = 0.196 [95% confidence interval: 0.037, 0.355], z = 2.410, p = 0.016), after controlling for age, gender, diabetes duration, hemoglobin A1c level, and CRT. CONCLUSIONS: Retinal neurodegenerative changes show a steady progression during a 3-year period of follow-up in eyes with NPDR and appear to be directly associated with progression in decreased vessel density including vascular closure through preferential involvement of the DCP. Our findings provide evidence that retinal neuropathy is linked with microvascular changes occurring in diabetic patients.

Characterization of two-year progression of different phenotypes of nonproliferative diabetic retinopathy.

INTRODUCTION: To characterize the two-year progression of risk phenotypes of nonproliferative diabetic retinopathy (NPDR) in type 2 diabetes (T2D) Phenotype C, or ischemic phenotype, identified by decreased skeletonized retinal vessel density (VD), ≥ 2 SD over normal values, and Phenotype B, or edema phenotype, identified by increased retinal thickness, i.e. subclinical macular edema, and no significant decrease in VD. METHODS: A prospective longitudinal cohort study (CORDIS, NCT03696810) was conducted with 4 visits (baseline, 6-months, one-year and two-year). Ophthalmological examinations included best corrected visual acuity, color fundus photography (CFP) and optical coherence tomography (OCT) and OCT Angiography. Early Treatment Diabetic Retinopathy Study grading was performed at the baseline and last visits based on 7-fields CFP. RESULTS: One hundred and twenty-two eyes from T2D individuals with NPDR fitted in the categories of phenotype B and C and completed the two-years follow-up. Sixty-five (53%) of the eyes were classified as phenotype B and 57 (47%) eyes as phenotype C. Neurodegeneration represented by thinning of the ganglion cell layer and inner plexiform layer was present in both phenotypes and showed significant progression over the two-year period (p<0.001). In phenotype C, significant progression in the two-year period was identified in decreased skeletonized VD (p=0.01), whereas in phenotype B microvascular changes involved preferentially decreases in perfusion density (PD, p=0.012). Phenotype B with changes in VD and PD (flow) and preferential involvement of the deep capillary plexus (p<0.001) is associated with development of center-involved macular edema. DISCUSSION: In the two-year period of follow-up both phenotypes B and C showed progression in retinal neurodegeneration, with changes at the microvascular level characterized by decreases in PD in phenotype B and decreases in VD in phenotype C.

Standardization of Optical Coherence Tomography Angiography Imaging Biomarkers in Diabetic Retinal Disease.

Optical coherence tomography Angiography (OCT-A) represents a revolution in the noninvasive evaluation of retinal and choroidal circulation especially in detecting early clinical signs of diabetic retinal disease (DRD). With appropriate use, OCT-A characteristics and measurements have the potential to become new imaging biomarkers in managing and treating DRD. Major challenges include (a) provision of standardized outputs from different OCT-A instruments providing standardized terminology to correctly interpret data; (b) the presence of artifacts; (c) the absence of standardized grading or interpretation method in the evaluation of DRD, similar to that already established in fundus photography; and (d) establishing how OCT-A might be able to provide surrogate markers to demonstrate blood retinal barrier breakdown and vascular leakage, commonly associated with DRD. In fact, OCT-A guidelines for DRD are still evolving. The outputs of quantitative OCT-A data offer a unique opportunity to develop tools based on artificial intelligence to assist the clinicians in diagnosing, monitoring, and managing patients with diabetes. In addition, OCT-A has the potential to become a useful tool for the evaluation of cardiovascular diseases and different neurological diseases including cognitive impairment. This article written by the members of Diabetic Retinopathy expert committee of the European Vision Clinical Research network will review the available evidence on the use of OCT-A as an imaging biomarker in DRD and discuss the limits and the current application as well as future developments for its use in both clinical practice and research trials of DRD.

Characterization of Initial Stages of Diabetic Macular Edema.

PURPOSE: This study is aimed at characterizing the type of retinal edema in the initial stages of retinopathy in type 2 diabetes. METHODS: In this retrospective cross-sectional study, spectral domain optical coherence tomography (OCT) layer by layer analysis of the retina in association with OCT-Leakage, an algorithm to detect sites of low optical reflectivity, were used to examine eyes with minimal, mild, and moderate diabetic retinopathy (DR). RESULTS: A total of 142 eyes from 142 patients (28% women) aged 52-88 years were imaged. Macular edema, either subclinical (SCME) or central-involved macular edema (CIME), was present in 43% of eyes in group 10-20, 41% of eyes in group 35, and 38% of eyes in group 43-47. The inner nuclear layer (INL) was the layer showing higher and most frequent increases in retinal thickness (79%). The edema was predominantly intracellular in group 10-20 (65%) and extracellular in groups 35 (77%) and 43-47 (69%). CONCLUSIONS: Eyes from diabetic patients in the initial stages of DR with different Early Treatment Diabetic Retinopathy Study gradings show similar prevalence of SCME and CIME, independent of the severity of the retinopathy. Retinal edema is located mainly in the INL and appears to be mostly extracellular except in the earliest stages of diabetic retinal disease where intracellular edema predominates.

Treatment of exudative age-related macular degeneration with intravitreal ranibizumab in clinical practice: a 3-year follow-up.

PURPOSE: To evaluate the 36-month efficacy of intravitreal ranibizumab injections for choroidal neovascularization secondary to age-related macular degeneration (AMD) in real world clinical practice. METHODS: Retrospective study involving 84 eyes of 77 patients; 52 eyes completed 3 years of follow-up. Subjects were observed initially on a monthly basis and with extended follow-up intervals if signs of quiescence were detected, according to an established protocol. A comprehensive ophthalmologic examination was performed, including best-corrected visual acuity (BCVA) determined with Early Treatment Diabetic Retinopathy Study charts, stereoscopic macular biomicroscopy and optical coherence tomography (OCT) with fluorescein angiography and indocyanine green angiography if considered necessary. Treatment was given if signs of active lesions were present. RESULTS: The mean baseline BCVA was 49.33 and 49.52 letters at the 36-month visit. The average of treatments was 8.6 at 3 years. At this time point, 77% of treated eyes stabilized or improved their vision (VA loss ≤ 5 letters). A predictive value for better VA was found for younger age, better baseline VA, good response on OCT and more frequent treatments. CONCLUSION: At 3 years, intravitreal ranibizumab is able to maintain baseline VA in exudative AMD patients, with a reduced number of injections, but not to show VA improvement, in clinical practice.

Characterisation of progression of macular oedema in the initial stages of diabetic retinopathy: a 3-year longitudinal study.

BACKGROUND/OBJECTIVES: To characterise the prevalence and three-year progression of centre-involving diabetic macular oedema (CI-DMO) in minimal to moderate non-proliferative diabetic retinopathy, using optical coherence tomography (OCT) and measurements of retinal fluid using tissue optical reflectivity ratios (OCT-Leakage). METHODS/METHODS: Seventy-four eyes from 74 patients were followed in a 3-year prospective longitudinal observational cohort of type 2 diabetes (T2D) patients using spectral-domain optical coherence tomography (SD-OCT), OCT-Angiography (OCT-A) and OCT-Leakage (OCT-L). Eyes were examined four times with 1-year intervals. Sixteen eyes (17.8%) were excluded from the analysis due to quality control standards. Retinal oedema was measured by central retinal thickness and retinal fluid by using optical reflectivity ratios obtained with the OCT-L algorithm. Vessel density was measured by OCT-A. Thinning of the ganglion cell and inner plexiform layers (GCL + IPL) was examined to identify retinal neurodegenerative changes. Diabetic retinopathy ETDRS classification was performed using the seven-field ETDRS protocol. RESULTS: CI-DMO was identified in the first visit in 9% of eyes in ETDRS groups 10-20, 10% of eyes in ETDRS group 35 and 15% of eyes in ETDRS groups 43-47. The eyes with CI-DMO and subclinical CI-DMO showed a progressive increase in retinal extracellular fluid during the 3-year period of follow-up. The eyes with CI-DMO and increased retinal extracellular fluid accumulation were associated with vision loss. CONCLUSIONS: The prevalence of subclinical CI-DMO and CI-DMO in the initial stages of NPDR occurs independently of severity grading of the retinopathy, showing progressive increase in retinal extracellular fluid and this increase is associated with vision loss (82% 9 out of 11 cases).

Different Risk Profiles for Progression of Nonproliferative Diabetic Retinopathy: A 2-Year Study.

INTRODUCTION: Characterization of 2-year progression of different risk phenotypes in eyes with mild and moderate nonproliferative diabetic retinopathy (NPDR) in type 2 diabetes (T2D). METHODS: A 2-year prospective longitudinal cohort study (CORDIS, NCT03696810) was conducted. Ophthalmological examinations were performed including best corrected visual acuity, color fundus photography and optical coherence tomography (OCT and OCTA). OCT metrics, central retinal thickness and ganglion cell layer + inner plexiform layer (GCL + IPL) thickness were analyzed. OCTA metrics, vessel density (VD), perfusion density (PD) and area of intercapillary spaces (AIS) were obtained from superficial and deep capillary plexus (SCP, DCP). Only phenotype C identified by decreased VD ≥ 2 SD of healthy controls and phenotype B identified by subclinical macular edema with decreased VD < 2 SD of healthy controls were included. RESULTS: One hundred twenty-two eyes from T2D individuals were included in study; 65 eyes (53%) were classified as phenotype B and 57 eyes (47%) as phenotype C. For phenotype B, progression was associated with thinning of the GCL + IPL (ETDRS 35, 1 year p = 0.013, 2 year p < 0.001; ETDRS 43-47, 2 year p = 0.003) and vessel closure involving mainly the DCP for both ETDRS grades (ETDRS 35, 1 year p = 0.025, 2 year p = 0.034; ETDRS 43-47, 1 year p = 0.011). For phenotype C there was also progressive thinning of the GCL + IPL (ETDRS 35, in both years p ≤ 0.001; ETDRS 43-47, 1 year p = 0.002, 2 year p = 0.001), with vessel closure involving mainly SCP (ETDRS 35, 1 year p = 0.012, 2 year p = 0.023 in full-retina), which appeared to stabilize at maximal values in ETDRS grade 43-47 at the end of 2 years. ETDRS severity changes at the end of the 2-year period showed that worsening was associated with phenotype C with changes involving predominantly the SCP (VD, p = 0.005; PD, p = 0.008; AIS, p = 0.005). CONCLUSIONS: Association between ETDRS classification of NPDR severity and identification of different risk phenotypes offers new perspective to predict disease progression in T2D individuals with NPDR.

Characterization of One-Year Progression of Risk Phenotypes of Diabetic Retinopathy.

INTRODUCTION: We characterized the progression of different diabetic retinopathy (DR) phenotypes in type 2 diabetes (T2D). METHODS: A prospective longitudinal cohort study (CORDIS, NCT03696810) was conducted with three visits (baseline, 6 months, and 1 year). Demographic and systemic data included age, sex, diabetes duration, lipid profile, and hemoglobin A1c (HbA1c). Ophthalmological examinations included best-corrected visual acuity (BCVA), color fundus photography (CFP), and optical coherence tomography (OCT and OCTA). Phenotype classification was performed at the 6-month visit based on microaneurysm turnover (MAT, on CFP) and central retinal thickness (CRT, on OCT). Only risk phenotypes B (MAT < 6 and increased CRT) and C (MAT ≥ 6 with or without increased CRT) were included. ETDRS grading was performed at the baseline visit based on seven-field CFP. RESULTS: A total of 133 T2D individuals were included in the study; 81 (60%) eyes were classified as phenotype B and 52 (40%) eyes as phenotype C. Of these, 128 completed the 1-year follow-up. At baseline, eyes with phenotype C showed greater capillary closure (superior capillary plexus, deep capillary plexus, and full retina, p < 0.001) and increased foveal avascular zone (FAZ) area (p < 0.001), indicating more advanced microvascular disease. Neurodegeneration represented by thinning of the ganglion cell layer + inner plexiform layer (GCL + IPL) was present in both phenotypes. When analyzing the 1-year progression of each phenotype, only phenotype C revealed a significant decrease in BCVA (p = 0.02) and enlargement of the FAZ (p = 0.03). A significant progressive decrease in the vessel density of the deep capillary layer and in MAT occurred in both phenotypes, but these changes were particularly relevant in phenotype C and ETDRS grades 43-47. During the 1-year period, both phenotypes B and C showed progression in GCL + IPL thinning (p < 0.001). CONCLUSIONS: In the 1-year period of follow-up, both phenotypes B and C showed progression in retinal neurodegeneration, whereas phenotype C showed more marked disease progression at the microvascular level.

Comparison of Different Metrics for the Identification of Vascular Changes in Diabetic Retinopathy Using OCTA.

Retinal vessel metrics identifying microvascular changes such as vessel closure (VC) have shown potential clinical value by identifying eyes with diabetic retinopathy (DR) at different severity levels and at increased risk for disease progression to more severe stages. We compare the performance of 11 different metrics, which include 2 metrics supplied by the manufacturer, based on OCTA for identification of VC in different Early Treatment for Diabetic Retinopathy Study (ETDRS) severity groups. OCTA en-face slabs from 84 healthy eyes (70 ± 4.8 years) and 78 eyes of diabetic individuals (67 ± 7.5 years) were processed using different methods that include abnormal intercapillary spaces (AIS), vessel density (VD), and nine metrics extracted from the en-face slab. The best separation between the eyes with DR and the control group was obtained in the superficial capillary plexus (SCP), with the full retina (FR) also performing well. In the SCP, the metrics that show better performance were the AIS and the VD with a value of area under curve (AUC) equal to 0.89 [95% CI 0.84-0.94] and 0.85 [95% CI 0.79-0.91], respectively, indicating that the VD metric supported by the manufacturer is satisfactory. The values of these metrics on the different ETDRS groups show a progressive increase in VC, which is correlated with disease severity.

Retinal Neurodegeneration in Different Risk Phenotypes of Diabetic Retinal Disease.

Diabetic retinopathy (DR) has been considered a microvascular disease, but it has become evident that neurodegeneration also plays a key role in this complex pathology. Indeed, this complexity is reflected in its progression which occurs at different rates in different type 2 diabetic (T2D) individuals. Based on this concept, our group has identified three DR progression phenotypes that might reflect the interindividual differences: phenotype A, characterized by low microaneurysm turnover (MAT <6), phenotype B, low MAT (<6) and increased central retinal thickness (CRT); and phenotype C, with high MAT (≥6). In this study, we evaluated the progression of DR neurodegeneration, considering ganglion cell+inner plexiform layers (GCL+IPL) thinning, in 170 T2D individuals followed for a period of 5 years, to explore associations with disease progression or risk phenotypes. Ophthalmological examinations were performed at baseline, first 6 months, and annually. GCL+IPL average thickness was evaluated by optical coherence tomography (OCT). Microaneurysm turnover (MAT) was evaluated using the RetMarkerDR. ETDRS level and severity progression were assessed in seven-field color fundus photography. In the overall population there was a significant loss in GCL+IPL (-0.147 µm/year), independently of glycated hemoglobin, age, sex, and duration of diabetes. Interestingly, this progressive thinning in GCL + IPL reached higher values in phenotypes B and C (-0.249 and -0.238 µm/year, respectively), whereas phenotype A remained relatively stable. The presence of neurodegeneration in all phenotypes suggests that it is the retinal vascular response to the early neurodegenerative changes that determines the course of the retinopathy in each individual. Therefore, classification of different DR phenotypes appears to offer relevant clarification of DR disease progression and an opportunity for improved management of each T2D individual with DR, thus playing a valuable role for the implementation of personalized medicine in DR.

Microaneurysm Turnover in Mild Non-Proliferative Diabetic Retinopathy is Associated with Progression and Development of Vision-Threatening Complications: A 5-Year Longitudinal Study.

BACKGROUND: Analysis of retinal microaneurysm turnover (MAT) has been previously shown to contribute to the identification of eyes at risk of developing clinically significant complications associated with diabetic retinopathy (DR). We propose to further characterize MAT as a predictive biomarker of DR progression and development of vision-threatening complications. METHODS: 212 individuals with type 2 diabetes (T2D; ETDRS grades 20 and 35) were evaluated annually in a 5-year prospective, longitudinal study, by color fundus photography and optical coherence tomography. Endpoints were diabetic macular edema (DME) or proliferative retinopathy (PDR). MAT analysis included determination of MA formation and disappearance rates, automatically assessed using the RetMarkerDR®. Retinopathy severity progression was evaluated using step increases in ETDRS severity levels. RESULTS: Of the 212 individuals, 172 completed the 5-year follow-up study or developed an endpoint (n = 27). MAT calculated at 1 year showed a significant difference between groups of endpoint developments (p = 0.018), particularly MA disappearance rate (p = 0.007). MAT also showed a significant difference between eyes with different ETDRS severity progression in the 5-year period (p = 0.035). CONCLUSIONS: MAT is an indicator of the development of DME and/or PDR as well as of DR severity progression in T2D individuals with mild retinopathy.

Different retinopathy phenotypes in type 2 diabetes predict retinopathy progression.

PURPOSE: To characterize the progression in retinopathy severity of different phenotypes of mild nonproliferative diabetic retinopathy (NPDR) in patients with type 2 diabetes. DESIGN AND METHODS: Patients with type 2 diabetes and mild NPDR (ETDRS 20 or 35) were followed in a 5-year longitudinal study. Examinations, including color fundus photography (CFP) and optical coherence tomography (OCT and OCTA), were performed at baseline, 6 months and then annually. Phenotype classification was performed based on microaneurysm turnover (MAT, on CFP) and central retinal thickness (CRT, on OCT). Phenotype A is characterized by low MAT (< 6) and normal CRT; Phenotype B by low MAT (< 6) and increased CRT; and Phenotype C by higher MAT (≥ 6) with or without increased CRT. ETDRS grading of seven fields CFP was performed at the initial and last visits. RESULTS: Analysis of ETDRS grade step changes showed significant differences in diabetic retinopathy (DR) progression between the different phenotypes (p < 0.001). Of the 66 participants with phenotype A only 2 eyes (3%) presented 2-or-more-step worsening. None of the 50 participants characterized as phenotype B developed 2-step worsening, whereas 13 eyes (23.2%) characterized as phenotype C had 2-or-more-steps worsening. Phenotype C presents the higher risk for 2-or-more step worsening (OR: 15.94 95% CI: 3.45-73.71; p < 0.001) and higher sensitivity, correctly identifying 86.7% of cases at risk (AUC: 0.84 95% CI: 0.72-0.96; p < 0.001). Diabetic retinopathy severity progression was associated with HbA1c (p = 0.019), LDL levels (p = 0.043), and ocular factors as MAT (p = 0.010), MA formation rate (p = 0.014) and MA disappearance rate (p = 0.005). Capillary closure at 5-year follow-up, identified by lower vessel density (VD) on OCTA, was also associated with diabetic DR severity progression (p = 0.035). CONCLUSIONS: Different DR phenotypes in type 2 diabetes show different risks of retinopathy progression. Phenotype C is associated with increased HbA1c values and presents a higher risk of a 2-or-more-step worsening of the ETDRS severity score.

Optical Coherence Tomography Angiography Metrics Monitor Severity Progression of Diabetic Retinopathy-3-Year Longitudinal Study.

To examine retinal vessel closure metrics and neurodegenerative changes occurring in the initial stages of nonproliferative diabetic retinopathy (NPDR) and severity progression in a three-year period. Methods: Three-year prospective longitudinal observational cohort of individuals with type 2 diabetes (T2D), one eye per person, using spectral domain-optical coherence tomography (SD-OCT) and OCT-Angiography (OCTA). Eyes were examined four times with one-year intervals. OCTA vessel density maps of the retina were used to quantify vessel closure. Thickness of the ganglion cell + inner plexiform layer (GCL + IPL) was examined to identify retinal neurodegenerative changes. Diabetic retinopathy ETDRS classification was performed using the seven-field ETDRS protocol. Results: A total of 78 eyes/patients, aged 52 to 80 years, with T2D and ETDRS grades from 10 to 47 were followed for 3 years with annual examinations. A progressive increase in retinal vessel closure was observed. Vessel density (VD) showed higher decreases with retinopathy worsening demonstrated by step-changes in ETDRS severity scale (p < 0.001). No clear correlation was observed between neurodegenerative changes and retinopathy progression. Conclusions: Retinal vessel closure in NPDR correlates with DR severity progression. Our findings provide supporting evidence that OCTA metrics of vessel closure may be used as a surrogate for DR severity progression.

Characterization of Disease Progression in the Initial Stages of Retinopathy in Type 2 Diabetes: A 2-Year Longitudinal Study.

Purpose: To characterize 2-year changes occurring in neurodegeneration, edema, and capillary dropout in nonproliferative diabetic retinopathy. Methods: Two-year prospective longitudinal observational cohort of eyes/patients with type 2 diabetes using spectral domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA). Eyes were examined three times with intervals of 1 year. Thickness of the full retina and layer-by-layer measurements were used to identify edema or neurodegeneration. OCTA vessel density maps of the retina were used to identify capillary dropout. Early Treatment Diabetic Retinopathy Study (ETDRS) classification was performed using the seven-field ETDRS protocol. Results: A total of 62 eyes from 62 patients with diabetes were followed for 2 years. After verification for image quality, a total of 44 eyes from 44 patients (30% women) aged 52 to 80 years were retained for data analysis. There were 18 eyes with ETDRS grades 10 to 20, 17 eyes with ETDRS grade 35, and 9 eyes with ETDRS grades 43 to 47. During the 2-year follow-up period, there was a progressive increase in capillary dropout, whereas edema and neurodegeneration remained stable. In multivariate analysis, considering a model adjusted for age, sex, hemoglobin A1C, visual acuity, and diabetes duration, vessel density remained significantly different between Diabetic Retinopathy Severity Scale groups (Wilks' λ = 0.707; P = 0.015) showing association with disease progression. Conclusions: Capillary dropout increased in a period of 2 years in eyes with minimal, mild, and moderate diabetic retinopathy, whereas the presence of edema and neurodegeneration remained stable.

Retinopathy Phenotypes in Type 2 Diabetes with Different Risks for Macular Edema and Proliferative Retinopathy.

Our group reported that three diabetic retinopathy (DR) phenotypes: A, characterized by low microaneurysm turnover (MAT < 6) and normal central retinal thickness (CRT); B, low MAT (<6) and increased CRT, and C, high MAT (≥6), present different risks for development of macular edema (DME) and proliferative retinopathy (PDR). To test these findings, 212 persons with type 2 diabetes (T2D) and mild nonproliferative retinopathy (NPDR), one eye per person, were followed for five years with annual visits. Of these, 172 completed the follow-up or developed an outcome: PDR or DME (considering both clinically significant macular edema (CSME) and center-involved macular edema (CIME)). Twenty-seven eyes (16%) developed either CSME (14), CIME (10), or PDR (4), with one eye developing both CSME and PDR. Phenotype A showed no association with development of vision-threatening complications. Seven eyes with phenotype B and three with phenotype C developed CIME. Phenotype C showed higher risk for CSME development, with 17.41 odds ratio (p = 0.010), compared with phenotypes A + B. All eyes that developed PDR were classified as phenotype C. Levels of HbA1c and triglycerides were increased in phenotype C (p < 0.001 and p = 0.018, respectively). In conclusion, phenotype C identifies eyes at higher risk for development of CSME and PDR, whereas phenotype A identifies eyes at very low risk for vision-threatening complications.

Multimodal Imaging of the Initial Stages of Diabetic Retinopathy: Different Disease Pathways in Different Patients.

The objective of this study was to evaluate the prevalence of different disease pathways (ischemia, neurodegeneration, and edema) in the initial stages of diabetic retinopathy. In this retrospective cross-sectional study, eyes were grouped by diabetic retinopathy severity using the 7-field Early Treatment Diabetic Retinopathy Study (ETDRS) protocol (levels 10-20, 35, and 43-47). Neurodegeneration was identified by thinning of the retinal nerve fiber layer and/or ganglion cell layer. Edema was identified by thickening of the inner nuclear layer, outer plexiform layer, or full retina. Ischemia was identified by metrics of retinal vessel density. Imaging was performed in 142 eyes from 142 patients (28% women) aged 52-88 years. Vessel density (ischemia) was significantly different between the ETDRS groups (P < 0.020). On multivariate regression analysis, it remained significantly different between stages of the disease and showed associations with age (P < 0.001), sex (P = 0.028), and metabolic control (P = 0.034). No significant differences between ETDRS groups were found in retinal thinning (neurodegeneration) or retinal thickness (edema). Eyes with the same ETDRS retinopathy grading from different patients with diabetes showed that the prevalence of different disease pathways varies between patients, even within the same severity group. Ischemia (capillary dropout) is the only disease pathway that shows correlation with retinopathy severity and metabolic control.

Real-World Outcomes of Anti-VEGF Treatment for Retinal Vein Occlusion in Portugal.

PURPOSE: Retinal vein occlusion (RVO) is an important cause of visual disability in the modern world. We aim to evaluate the real-world outcomes of patients with RVO treated with anti-vascular endothelial growth factor (VEGF) in Portugal. METHODS: We performed a retrospective, observational, multicenter study including 8 centers across Portugal and 200 patients treated with either ranibizumab or bevacizumab. Data were collected at 3 time points: time of diagnosis (0 time point) and 6 and 12 months after initiating treatment. Demographic and clinical data were collected. RESULTS: Median visual acuity (VA) and central macular thickness (CMT) improved in the branch RVO (BRVO), central RVO (CRVO), bevacizumab, and ranibizumab groups at 6 and 12 months compared to baseline, with CMT improving further only in the CRVO and ranibizumab groups between 6 and 12 months (p = 0.002 and p = 0.001, respectively). The CMT was lower in the ranibizumab group compared to the bevacizumab group both at 6 and 12 months (p<0.02). Median CMT improved in both the good and poor baseline VA groups at 6 and 12 months compared to baseline (p<0.001). Median VA only improved for the group with poor baseline VA at 6 and 12 months of follow-up (p<0.001). Regression analysis identified several baseline variables as predictors of visual outcomes at 6 and 12 months, with different results depending on the analyzed group. CONCLUSIONS: Both treatments were effective, although less effective than results reported in clinical trials. The morphologic response was better with ranibizumab compared to bevacizumab, although functionally there were no differences.

OCT-Leakage Mapping: A New Automated Method of OCT Data Analysis to Identify and Locate Abnormal Fluid in Retinal Edema.

PURPOSE: To test OCT-Leakage, a new method of analyzing and mapping sites of lower optical reflectivity found on OCT, by examining eyes with various types of retinal edema to identify abnormal increases in retinal extracellular fluid. DESIGN: Prospective analysis of a cohort of cases. PARTICIPANTS: Healthy eyes and eyes with retinal edema in the setting of different retinal diseases. METHODS: Prospective OCT-Leakage analysis of 12 eyes with various types of retinal edema, such as diabetic macular edema, branch retinal vein occlusion, idiopathic perifoveal telangiectasia, and Irvine-Gass syndrome, representing intraretinal edema and eyes with idiopathic central serous chorioretinopathy and neovascular age-related macular degeneration representing subretinal fluid accumulation, in order to compare with OCT-Leakage analysis of a series of 41 eyes of 24 healthy controls. Raw scan data from the OCT images were exported and used to calculate lower than normal optical reflectivity maps (low optical reflectivity [LOR] ratios). Optical reflectivity LOR maps (OCT-Leakage maps) were collected for the full retina A-scan and layer by layer after segmentation. Low optical reflectivity ratios from patients with the different conditions of retinal edema and controls were compared. Fluorescein angiography (FA) and OCT angiography (OCTA) were performed in all eyes. MAIN OUTCOME MEASURES: Identification of areas of abnormal retinal fluid accumulation. RESULTS: The OCT-Leakage maps based on sites of LOR (LOR ratios) delineated the location of intraretinal and subretinal fluid, always integrating the location of the sites on FA and the vascular abnormalities observed on OCTA. The areas of fluid outline in the OCT-Leakage maps were coincident and generally larger than those seen on FA. In all cases, the OCT-Leakage maps were able to identify the location of the fluid in the different segmented retinal layers. CONCLUSIONS: Mapping of lower reflectivity sites within the retina demonstrates the amount and location of retinal and subretinal fluid in different retinal diseases, showing potential to contribute to their management. Furthermore, the possibility of complementarity between OCT-Leakage and OCTA is highly promising.