Retinal vascular bed area on ultra-wide field fluorescein angiography indicates the severity of diabetic retinopathy

Association of Predominantly Peripheral Lesions on Ultra-Widefield Imaging and the Risk of Diabetic Retinopathy Worsening Over Time

Importance

Ultra-widefield (UWF) imaging improves the ability to identify peripheral diabetic retinopathy (DR) lesions compared with standard imaging. Whether detection of predominantly peripheral lesions (PPLs) better predicts rates of disease worsening over time is unknown.

Objective

To determine whether PPLs identified on UWF imaging are associated with increased disease worsening beyond the risk associated with baseline Early Treatment Diabetic Retinopathy Study (ETDRS) Diabetic Retinopathy Severity Scale (DRSS) score.

Design, Setting, and Participants

This cohort study was a prospective, multicenter, longitudinal observational study conducted at 37 US and Canadian sites with 388 participants enrolled between February and December 2015. At baseline and annually through 4 years, 200° UWF-color images were obtained and graded for DRSS at a reading center. Baseline UWF-color and UWF-fluorescein angiography (FA) images were evaluated for the presence of PPL. Data were analyzed from May 2020 to June 2022.

Interventions

Treatment of DR or diabetic macular edema was at investigator discretion.

Main Outcomes and Measures

Predominantly peripheral lesions were defined as DR lesions with a greater extent outside vs inside the 7 standard ETDRS fields. Primary outcome was disease worsening defined as worsening 2 steps or more on the DRSS or receipt of DR treatment. Analyses were adjusted for baseline DRSS score and correlation between 2 study eyes of the same participant.

Results

Data for 544 study eyes with nonproliferative DR (NPDR) were analyzed (182 [50%] female participants; median age, 62 years; 68% White). The 4-year disease worsening rates were 45% for eyes with baseline mild NPDR, 40% for moderate NPDR, 26% for moderately severe NPDR, and 43% for severe NPDR. Disease worsening was not associated with color PPL at baseline (present vs absent: 38% vs 43%; HR, 0.78; 95% CI, 0.57-1.08; P = .13) but was associated with FA PPL at baseline (present vs absent: 50% vs 31%; HR, 1.72; 95% CI, 1.25-2.36; P < .001).

Conclusions and Relevance

Although no association was identified with color PPL, presence of FA PPL was associated with greater risk of disease worsening over 4 years, independent of baseline DRSS score. These results suggest that use of UWF-FA to evaluate retinas peripheral to standard ETDRS fields may improve the ability to predict disease worsening in NPDR eyes. These findings support use of UWF-FA for future DR staging systems and clinical care to more accurately determine prognosis in NPDR eyes.

Association of Ultra-Widefield Fluorescein Angiography-Identified Retinal Nonperfusion and the Risk of Diabetic Retinopathy Worsening Over Time

Importance

Presence of predominantly peripheral diabetic retinopathy (DR) lesions on ultra-widefield fluorescein angiography (UWF-FA) was associated with greater risk of DR worsening or treatment over 4 years. Whether baseline retinal nonperfusion assessment is additionally predictive of DR disease worsening is unclear.

Objective

To assess whether the extent and location of retinal nonperfusion identified on UWF-FA are associated with worsening in Diabetic Retinopathy Severity Scale (DRSS) score or DR treatment over time.

Design, Setting, and Participants

This cohort study was a prospective, multicenter, longitudinal observational study with data for 508 eyes with nonproliferative DR and gradable nonperfusion on UWF-FA at baseline. All images were graded at a centralized reading center; 200° ultra-widefield (UWF) color images were graded for DR at baseline and annually for 4 years. Baseline 200° UWF-FA images were graded for nonperfused area, nonperfusion index (NPI), and presence of predominantly peripheral lesions on UWF-FA (FA PPL).

Interventions

Treatment of DR or diabetic macular edema was at investigator discretion.

Main Outcomes and Measures

Association of baseline UWF-FA nonperfusion extent with disease worsening, defined as either 2 or more steps of DRSS worsening within Early Treatment Diabetic Retinopathy Study fields on UWF-color images or receipt of DR treatment.

Results

After adjusting for baseline DRSS, the risk of disease worsening over 4 years was higher in eyes with greater overall NPI (hazard ratio [HR] for 0.1-unit increase, 1.11; 95% CI, 1.02-1.21; P = .02) and NPI within the posterior pole (HR for 0.1-unit increase, 1.35; 95% CI, 1.17-1.56; P < .001) and midperiphery (HR for 0.1-unit increase, 1.08; 95% CI, 1.00-1.16; P = .04). In a multivariable analysis adjusting for baseline DRSS score and baseline systemic risk factors, greater NPI (HR, 1.11; 95% CI, 1.02-1.22; P = .02) and presence of FA PPL (HR, 1.89; 95% CI, 1.35-2.65; P < .001) remained associated with disease worsening.

Conclusions and Relevance

This 4-year longitudinal study has demonstrated that both greater baseline retinal nonperfusion and FA PPL on UWF-FA are associated with higher risk of disease worsening, even after adjusting for baseline DRSS score and known systemic risk. These associations between disease worsening and retinal nonperfusion and FA PPL support the increased use of UWF-FA to complement color fundus photography in future efforts for DR prognosis, clinical care, and research.

A NEW BIOMARKER QUANTIFYING THE EFFECT OF ANTI-VEGF THERAPY IN EYES WITH PROLIFERATIVE DIABETIC RETINOPATHY ON ULTRA-WIDE FIELD FLUORESCEIN ANGIOGRAPHY: RECOVERY STUDY

PURPOSE

To quantify changes of the retinal vascular bed area (RVBA) in mm2 on stereographically projected ultra-wide field (UWF) fluorescein angiography (FA) images by in eyes with proliferative diabetic retinopathy (PDR) following anti-vascular endothelial growth factor (VEGF) injection.

METHODS

Prospective, observational study. The early-phase UWF FA images (Optos 200Tx) of 40 eyes with PDR and significant non-perfusion obtained at baseline and after 6 months (NCT02863354) were stereographically projected by correcting peripheral distortion. The global retinal vasculature on UWF FA was extracted for calculating RVBA by summing the real size (mm2) of all the pixels automatically.

RESULTS

For the entire cohort, global RVBA for the entire retina decreased from 67.1 ± 15.5 mm2 to 43.6 ± 18.8 mm2 after anti-VEGF treatment at 6 months (P < 0.001). In the sub-group receiving monthly anti-VEGF injections, global RVBA decreased from 68.7 ± 16.2 mm2 to 33.9 ± 13.3 mm2 (P < 0.001). In the sub-group receiving anti-VEGF every 3 months, global RVBA decreased from 65.6 ± 15.1 mm2 to 50.8 ± 19.3 mm2 (P = 0.004).

CONCLUSIONS

RVBA appears to be a new biomarker to indicate efficiency of retinal vascular changes after anti-VEGF injection. Eyes with PDR and significant non-perfusion demonstrate reduced RVBA following anti-VEGF treatment.

Association of Subregional Quantitative Ultra-widefield Fluorescence Angiography Characteristics With the Occurrence of Diabetic Macular Edema and Proliferative Diabetic Retinopathy

Purpose: To explore the relationships of region-specific properties of ultra-widefield fluorescence angiography (UWFFA) images with two adverse outcomes, diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR), and also the severity of diabetic retinopathy (DR).

Methods: A cross-sectional observational study was performed to retrospectively analyze UWFFA images of patients with DR. All patients underwent UWFFA and optical coherence tomography examination. Leakage index and microaneurysm (MA) count were measured using Trainable Weka Segmentation, a machine learning algorithm, and ischemic index (ISI) was measured manually. The correlation between UWFFA parameters and severity of DR was analyzed, and receiver operating characteristic curves were used to estimate their diagnostic value for DME and PDR.

Results: A total of 108 eyes from 108 patients with DR (mean age of 56.04 ± 8.85 years) were analyzed. As the severity of DR increased, the ISI and leakage index of the panretina and all subregions increased. Panretinal MA count and leakage index were significantly higher in eyes with DME than those without DME (p = 0.044 and 0.001, respectively). Leakage index and ISI were significantly higher in eyes with PDR than those without PDR in both panretinal and subregion-specific measurements (all p < 0.05). Throughout the retina and specifically in the posterior area (PoA), the leakage index had a higher diagnostic value for DME than ISI or MA count (all p < 0.05). The diagnostic value of MA count for PDR was lower than that of ISI and leakage index (all p < 0.05).

Conclusion: The ISI, leakage index, and MA count in the PoA and panretina correlated with the severity of DR, especially the posterior parameter. The leakage index was more valuable than ISI and MA count in determining the occurrence of DME. ISI and leakage index were better predictors of PDR.

Ultrawide Field Imaging in Diabetic Retinopathy: Exploring the Role of Quantitative Metrics

Ultrawide field imaging (UWF) has allowed the visualization of a significantly greater area of the retina than previous standard approaches. In diabetic retinopathy (DR), significantly more lesions are seen on UWF imaging compared to the seven-standard ETDRS fields. In addition, some eyes have lesions that are located predominantly in the peripheral retina that are associated with an increased risk of DR progression. The current DR severity scales are still largely based on clinically visible retinal microvascular lesions and do not incorporate retinal periphery, neuroretinal, or pathophysiologic changes. Thus, current scales are not well suited for documenting progression or regression in eyes with very early or advanced DR, nor in the setting of vascular endothelial growth factor inhibitors (antiVEGF). In addition, the categorical system is highly subjective, and grading is variable between different graders based on experience level and training background. Recently, there have been efforts to quantify DR lesions on UWF imaging in an attempt to generate objective metrics for classification, disease prognostication and prediction of treatment response. The purpose of this review is to examine current quantitative metrics derived from UWF fluorescein angiograms and UWF color imaging to determine their feasibility in any potential future DR classification.

Contribution of ultra-wide field fluorescein angiography in diabetic retinopathy in a Tunisian population

AIM

To assess the contribution of ultra-wide field (UWF) fluorescein angiography (FA) in clinically non proliferative diabetic retinopathy (DR) and to study the relationship between peripheral vascular lesions and the presence of diabetic macular edema (DME).

METHODS

Retrospective study of consecutive UWF-FA obtained using a wide-field contact lens system. DME was detected on both FA and spectral-domain optical coherence tomography (SD-OCT).

RESULTS

A total of 71 eyes of 39 diabetic patients with clinically non proliferative DR (NPDR) was included. DR was clinically graded as severe NPDR in 52 eyes (73%), moderate NPDR in 15 eyes (21%) and mild NPDR in 4 eyes (6%). On UWF-FA, DR was predominantly anterior in 14% of cases (10/71), predominantly posterior in 48% of cases (34/71) and diffuse in 38% of cases (27/71). Retinal non perfusion was present in 87% of eyes (62/71), predominating in superior-temporal areas. Peripheral vessel leakage was present in 85% of cases (60/71) and retinal neovascularization was noted in 14% of cases (10/71), unpgrading DR severity from NPDR to proliferative DR in 10 eyes. DME was present on SD-OCT in 53% of cases. Central macular thickness was significantly higher in eyes with retinal non-perfusion (353 μm vs. 254 μm, p=0,006) and retinal non-perfusion was associated with macular edema (97% vs. 76%, p=0,01) and poor visual acuity (p<0.001). Peripheral vessel leakage was associated with retinal non-perfusion (p<0.001) and retinal neovascularization (53% vs. 35%, p=0.01), but it was not associated with the presence of DME (p=0.449).

CONCLUSION

UWF-FA was of great help assessing DR and evaluating peripheral retinal lesions in order to refine DR staging and to guide laser treatment. Besides, it allows better understanding of DME pathophysiology.