Ultra-widefield Fluorescein Angiography Images Research Articles

Exploring the angiographic-biologic phenotype in the IMAGINE study: quantitative UWFA and cytokine expression

BackgroundThis study investigates the association of intraocular cytokine expression and ultrawide-field fluorescein angiography (UWFA) quantitative imaging biomarkers and their association with angiographical feature response after antivascular endothelial growth factor (VEGF)...

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

AimsTo quantify retinal vascular bed area (RVBA) in square millimetres on stereographically projected ultra-wide field (UWF) fluorescein angiography (FA) in eyes with diabetic retinopathy (DR).MethodsA prospective, observational study. Baseline Optos...

Dynamic versus static ultra-widefield fluorescein angiography in eyes with diabetic retinopathy: a pilot prospective cross-sectional study.

To analyze differences in ultra-widefield fluorescein angiography (UWFA) findings between dynamic and static images of eyes with diabetic retinopathy (DR). This cross-sectional study included 28 eyes of 28 patients with DR undergoing UWFA. A series of UWFA images acquired from each patient were converted into a time-lapse video and used as a dynamic image. A single, clear, arteriovenous phase image was chosen as a static image. Non-perfusion index (NPI) and its correlation with vascular abnormalities in different zones were compared between dynamic and static UWFA imaging. NPI appeared to increase from the center to the far-periphery in both groups. Dynamic NPI was lower in the total retinal area (0.26 vs 0.29, P=0.009) and far-periphery (0.33 vs 0.36, adjusted P=0.042), which was contrary to the static NPI. Far-peripheral NPI was associated with intraretinal microvascular abnormality in the posterior area in both groups. Time-lapse dynamic UWFA imaging is a useful modality to differentially diagnose hypofluorescence in the most peripheral region. This modality could provide a reliable method for NPI measurement.

Longitudinal assessment of quantitative ultra-widefield ischaemic and vascular parameters in sickle cell retinopathy

PurposeTo evaluate longitudinal quantitative ischaemic and vasculature parameters, including ischaemic index, vessel area, length and geodesic distance in sickle cell retinopathy (SCR) on ultra-widefield fluorescein angiography (UWFA).MethodsOptimal UWFA images from...

Automated Quality Assessment and Image Selection of Ultra-Widefield Fluorescein Angiography Images through Deep Learning.

PurposeNumerous angiographic images with high variability in quality are obtained during each ultra-widefield fluorescein angiography (UWFA) acquisition session. This study evaluated the feasibility of an automated system for image quality classification and selection using deep learning.MethodsThe training set was comprised of 3543 UWFA images. Ground-truth image quality was assessed by expert image review and classified into one of four categories (ungradable, poor, good, or best) based on contrast, field of view, media opacity, and obscuration from external features. Two test sets, including randomly selected 392 images separated from the training set and an independent balanced image set composed of 50 ungradable/poor and 50 good/best images, assessed the model performance and bias.ResultsIn the randomly selected and balanced test sets, the automated quality assessment system showed overall accuracy of 89.0% and 94.0% for distinguishing between gradable and ungradable images, with sensitivity of 90.5% and 98.6% and specificity of 87.0% and 81.5%, respectively. The receiver operating characteristic curve measuring performance of two-class classification (ungradable and gradable) had an area under the curve of 0.920 in the randomly selected set and 0.980 in the balanced set.ConclusionsA deep learning classification model demonstrates the feasibility of automatic classification of UWFA image quality. Clinical application of this system might greatly reduce manual image grading workload, allow quality-based image presentation to clinicians, and provide near-instantaneous feedback on image quality during image acquisition for photographers.Translational RelevanceThe UWFA image quality classification tool may significantly reduce manual grading for clinical- and research-related work, providing instantaneous and reliable feedback on image quality.

Automated vessel density detection in fluorescein angiography images correlates with vision in proliferative diabetic retinopathy.

PurposeTo investigate the correlation between quantifiable vessel density, computed in an automated fashion, from ultra-widefield fluorescein angiography (UWFFA) images from patients with proliferative diabetic retinopathy (PDR) with visual acuity and macular thickness.MethodsWe performed a secondary analysis of a prospective randomized controlled trial. We designed and trained an algorithm to automate retinal vessel detection from input UWFFA images. We then used our algorithm to study the correlation between baseline vessel density and best corrected visual acuity (BCVA) and CRT for patients in the RECOVERY study. Reliability of the algorithm was tested using the intraclass correlation (ICC). 42 patients from the Intravitreal Aflibercept for Retinal Non-Perfusion in Proliferative Diabetic Retinopathy (RECOVERY) trial who had both baseline UWFFA images and optical coherence tomography (OCT) data were included in our study. These patients had PDR without significant center-involving diabetic macular edema (central retinal thickness [CRT] ≤320μm).ResultsOur algorithm analyzed UWFFA images with a reliability measure (ICC) of 0.98. A positive correlation (r = 0.4071, p = 0.0075) was found between vessel density and BCVA. No correlation was found between vessel density and CRT.ConclusionsOur algorithm is capable of reliably quantifying vessel density in an automated fashion from baseline UWFFA images. We found a positive correlation between computed vessel density and BCVA in PDR patients without center-involving macular edema, but not CRT.Translational relevanceOur work is the first to offer an algorithm capable of quantifying vessel density in an automated fashion from UWFFA images, allowing us to work toward studying the relationship between retinal vascular changes and important clinical endpoints, including visual acuity, in ischemic eye diseases.

Longitudinal panretinal microaneurysm dynamics on ultra-widefield fluorescein angiography in eyes treated with intravitreal aflibercept for proliferative diabetic retinopathy in the recovery study

Background/AimsQuantifying microaneurysms (MAs) turnover may be an objective measure for therapeutic response in diabetic retinopathy. This study assesses changes in MA counts on ultra-widefield fluorescein angiography (UWFA) in subjects undergoing...

Deep Learning-Based Segmentation and Quantification of Retinal Capillary Non-Perfusion on Ultra-Wide-Field Retinal Fluorescein Angiography.

Reliable outcome measures are required for clinical trials investigating novel agents for preventing progression of capillary non-perfusion (CNP) in retinal vascular diseases. Currently, accurate quantification of topographical distribution of CNP on ultrawide field fluorescein angiography (UWF-FA) by retinal experts is subjective and lack standardisation. A U-net style network was trained to extract a dense segmentation of CNP from a newly created dataset of 75 UWF-FA images. A subset of 20 images was also segmented by a second expert grader for inter-grader reliability evaluation. Further, a circular grid centred on the FAZ was used to provide standardised CNP distribution analysis. The model for dense segmentation was five-fold cross-validated achieving area under the receiving operating characteristic of 0.82 (0.03) and area under precision-recall curve 0.73 (0.05). Inter-grader assessment on the 20 image subset achieves: precision 59.34 (10.92), recall 76.99 (12.5), and dice similarity coefficient (DSC) 65.51 (4.91), and the centred operating point of the automated model reached: precision 64.41 (13.66), recall 70.02 (16.2), and DSC 66.09 (13.32). Agreement of CNP grid assessment reached: Kappa 0.55 (0.03), perfused intraclass correlation (ICC) 0.89 (0.77, 0.93), non-perfused ICC 0.86 (0.73, 0.92), inter-grader agreement of CNP grid assessment values are Kappa 0.43 (0.03), perfused ICC 0.70 (0.48, 0.83), non-perfused ICC 0.71 (0.48, 0.83). Automated dense segmentation of CNP in UWF-FA images achieves performance levels comparable to inter-grader agreement values. A grid placed on the deep learning-based automatic segmentation of CNP generates a reliable and quantifiable method of measurement of CNP, to overcome the subjectivity of human graders.

SEVERITY OF DIABETIC MACULAR EDEMA CORRELATES WITH RETINAL VASCULAR BED AREA ON ULTRA-WIDE FIELD FLUORESCEIN ANGIOGRAPHY: DAVE Study.

To quantify retinal nonperfusion area and retinal vascular bed area (RVBA) in mm on ultra-widefield fluorescein angiography in eyes with diabetic macular edema (DME) and explore their relationship with the severity of DME. Prospective, observational case series. Baseline ultra-widefield fluorescein angiography images of 40 eyes from 29 patients with treatment-naive DME who participated in the DAVE study (NCT01552408) were stereographically projected at Doheny Image Reading Center. The retinal vasculature was automatically extracted to calculate RVBA. Nonperfusion area was manually delineated by two masked certified graders. Retinal vascular bed area and nonperfusion area were computed in mm automatically by adjusting for peripheral distortion and then correlated with the severity of DME. The global RVBA for the entire retina in eyes with DME was increased compared with healthy controls (54.7 ± 16.6 mm vs. 37.2 ± 9.9 mm, P < 0.001) and correlated with the severity of DME (P < 0.05). Retinal ischemia (nonperfusion area) was nonuniformly distributed and not related to DME extent (P > 0.05). Eyes with DME have an increased RVBA compared with healthy controls. The severity of DME appears to be related to global RVBA, but not to retinal ischemia.

Observation of the far peripheral retina of normal eyes by ultra-wide field fluorescein angiography.

The appearance of the far peripheral retina in normal eyes was observed using an Optos ultra-wide field fluorescein angiography imaging system. A cross-sectional study of ultra-wide field pseudocolor and angiography images obtained using the Optos 200Tx. Four different non-vascular and six vascular-associated fluorescence features in far peripheral retina were analyzed. A total of 166 eyes in 83 patients met the inclusion criteria. The mean patient age was 40.78 ± 10.94 years (range: 20-65 years) with a female-to-male ratio of 0.98. Slight cataract were present in 64 eyes (38.55%), low to moderate myopia in 50 eyes (30.12%), and unspecified visual disturbances in 52 eyes (31.33%). Far peripheral retinas were found to have mottled florescent band in 42.17% eyes, ground glass hyperfluorescence in 84.34% eyes, granular hyperfluorescence in 12.65% eyes, local mottled fluorescence in 10.84% eyes, vascular anastomosis with a peripheral avascular area in 36.23% eyes, invisible capillary details in 50.67% eyes, vessels passing through the ora serrata in 16.98% eyes, late-phase slight leakage in 32.53% eyes, angiectasis in 18.67% eyes, and microaneurysm in 34.94% eyes. Ultra-wide field fluorescein angiography revealed various fluorescence features in the periphery of normal eyes, providing a basis for interpreting normal and pathological changes in peripheral retina and an important reference for clinical work.

Weakly-Supervised Vessel Detection in Ultra-Widefield Fundus Photography via Iterative Multi-Modal Registration and Learning.

We propose a deep-learning based annotation-efficient framework for vessel detection in ultra-widefield (UWF) fundus photography (FP) that does not require de novo labeled UWF FP vessel maps. Our approach utilizes concurrently captured UWF fluorescein angiography (FA) images, for which effective deep learning approaches have recently become available, and iterates between a multi-modal registration step and a weakly-supervised learning step. In the registration step, the UWF FA vessel maps detected with a pre-trained deep neural network (DNN) are registered with the UWF FP via parametric chamfer alignment. The warped vessel maps can be used as the tentative training data but inevitably contain incorrect (noisy) labels due to the differences between FA and FP modalities and the errors in the registration. In the learning step, a robust learning method is proposed to train DNNs with noisy labels. The detected FP vessel maps are used for the registration in the following iteration. The registration and the vessel detection benefit from each other and are progressively improved. Once trained, the UWF FP vessel detection DNN from the proposed approach allows FP vessel detection without requiring concurrently captured UWF FA images. We validate the proposed framework on a new UWF FP dataset, PRIME-FP20, and on existing narrow-field FP datasets. Experimental evaluation, using both pixel-wise metrics and the CAL metrics designed to provide better agreement with human assessment, shows that the proposed approach provides accurate vessel detection, without requiring manually labeled UWF FP training data.

Retinal Nonperfusion in Proliferative Diabetic Retinopathy Before and After Panretinal Photocoagulation Assessed by Widefield OCT Angiography

Widefield swept source optical coherence tomography angiography (WF SS-OCTA) imaging was compared with ultra-widefield (UWF) fluorescein angiography (FA) imaging to better understand changes in retinal nonperfusion before and after panretinal photocoagulation (PRP) in treatment-naïve eyes with proliferative diabetic retinopathy (PDR). Prospective, observational, consecutive case series. Participants with treatment-naïve PDR were imaged using the SS-OCTA 12-× 12-mm scan pattern at baseline and at 1week, 1month, and 3months after PRP. UWF FA was obtained at baseline and 3months after PRP. Selected eyes were imaged using 5 SS-OCTA 12-× 12-mm scans to create a posterior pole montage, and 5 eyes also underwent SS-OCTA imaging at 6months and 1 year. Areas of retinal nonperfusion (RNP) were drawn independently by 2 masked graders, and analysis of variance (ANOVA) tests were used to compare areas of RNP over time. Main outcome measurements consisted of areas and boundaries of RNP visualized using WF SS-OCTA and UWF FA. From January 2018 through January 2019, WF SS-OCTA was performed on 20 eyes with treatment-naïve PDR from 15 patients. Areas of RNP identified on UWF FA images co-localized with RNP areas visualized on WF SS-OCTA images. There were no statistically significant changes in RNP area on WF SS-OCTA images through 3months after PRP. Even eyes that were severely ischemic at baseline had no significant changes in RNP area 1 year after PRP. RNP in PDR can be identified at baseline and imaged serially after PRP using WF SS-OCTA. Retinal perfusion in PDR does not change significantly after PRP. The ability of WF SS-OCTA to longitudinally evaluate RNP areas provides additional justification for adopting WF SS-OCTA as the sole imaging modality for clinical management of PDR.

Fluorescein Angiography Scoring System Using Ultra-Wide–Field Fluorescein Angiography Versus Standard Fluorescein Angiography in Patients with Sarcoid Uveitis

ABSTRACT Purpose: To compare standard fluorescein angiography (FA) and ultra-wide-field (UWF) FA in evaluating sarcoid uveitis activity using the scoring system adopted by the Angiography Scoring for Uveitis Working Group (ASUWG). Methods: Standard and UWF FA images of 36 eyes with sarcoid uveitis were acquired on the same day. Three graders independently graded 72 FA images using the ASUWG scoring system. We evaluated inter-observer variability using the intra-class correlation coefficient (ICC) and compared scores of each angiographic sign. Results: The ICC was 0.77 for standard FA and 0.87 for UWF FA, with respective total scores of 12.0 and 14.6. UWF FA had higher scores than standard FA for optic disc hyperfluorescence, posterior retinal vascular staining and/or leakage, and peripheral capillary leakage. Conclusions: The scores for UWF FA had a higher ICC than those for standard FA in evaluating sarcoid uveitis. Peripheral capillary leakage scores were particularly high for UWF FA.

Disparity of microaneurysm count between ultrawide field colour imaging and ultrawide field fluorescein angiography in eyes with diabetic retinopathy

AimsTo compare microaneurysm (MA) counts using ultrawide field colour images (UWF-CI) and ultrawide field fluorescein angiography (UWF-FA).MethodsRetrospective study including patients with type 1 or 2 diabetes mellitus receiving UWF-FA and...

RETINAL LEAKAGE INDEX DYNAMICS ON ULTRA-WIDEFIELD FLUORESCEIN ANGIOGRAPHY IN EYES TREATED WITH INTRAVITREAL AFLIBERCEPT FOR PROLIFERATIVE DIABETIC RETINOPATHY IN THE RECOVERY STUDY.

Characterization of leakage indices on ultra-widefield fluorescein angiography in proliferative diabetic retinopathy treated with intravitreal aflibercept. Prospective study enrolling subjects for treatment of proliferative diabetic retinopathy randomized 1:1 to receive 2-mg intravitreal aflibercept every 4 weeks (2q4) or every 12 weeks (2q12). Ultra-widefield fluorescein angiography images obtained at baseline, 24, and 48 weeks were analyzed using a semiautomated leakage segmentation platform. Panretinal and zonal leakage indices were calculated. Forty eyes of 40 subjects were included, and mean age was 48 ± 12.1 years. Mean number of injections was 11 ± 1.7 in the 2q4 arm and 4 ± 0.4 in the 2q12 arm. Median baseline leakage index in the 2q4 and 2q12 groups was 5.1% and 4.3%, respectively (P = 0.28). At 24 and 48 weeks, the 2q4 group significantly improved to 1.1% (-79%, P < 0.0001). At Week 24, the 2q12 group demonstrated nonsignificant improvement (3.4%; -21%, P = 0.47); by Week 48, improvement was significant (1.4%; -68%, P = 0.02). The 2q4 group resulted in lower leakage index compared with the 2q12 group at 24 weeks (1.1% vs. 3.4%, respectively; P = 0.008), but by 48 weeks, leakage index was similar between both groups (1.1% vs. 1.4%, respectively; P = 0.34). Proliferative diabetic retinopathy treated with intravitreal aflibercept demonstrated significant leakage index reductions at 1 year. Monthly dosing provided more rapid reduction in leakage index compared with quarterly dosing. RECOVERY study (NCT02863354); https://clinicaltrials.gov/ct2/show/NCT02863354.

Quantitative Ultra-Widefield Angiographic Features and Associations with Diabetic Macular Edema

To examine the relationship between diabetic macular edema (DME) and quantitative ultra-widefield fluorescein angiography (UWFA) metrics of ischemia, leakage, and microaneurysms. Retrospective image analysis study. Eyes with diabetic retinopathy that had undergone spectral-domain OCT, UWFA, and ultra-widefield fundus photography. OCT images were analyzed to determine the presence or absence of DME, central subfield thickness (CST), and subretinal fluid. Using a semiautomated analysis platform, UWFA images were segmented for ischemia, leakage, and microaneurysms with manual correction as needed. Clinical variables, including age, gender, race, hemoglobin A1C levels, blood pressure, cholesterol levels, use of blood thinners, smoking status, and lens status also were evaluated. Factors associated with the presence and severity of DME. A total of 304 eyes (156 right eyes, 148 left eyes) from 178 diabetic patients were analyzed in the study. Panretinal leakage index, microaneurysm count, and ischemic index were not significantly different between eyes with and without DME in univariate assessment. Zonal assessments of macular microaneurysms and macular leakage index values revealed that eyes with DME showed a significantly higher microaneurysm count (P= 0.001) and leakage index (P < 0.0001) in the posterior pole compared with eyes without DME. Severity of macular thickening (i.e., CST) was associated significantly with macular leakage index and posterior pole microaneurysm count (P= 0.0002 and P= 0.03, respectively). In addition to posterior pole leakage index and microaneurysm count, DME was associated with older age (P < 0.01), higher systolic blood pressure (P < 0.001), and white race (P= 0.03). Multivariate assessment confirmed the independent association of presence of DME with macular leakage index and macular microaneurysm count (P < 0.01). Quantitative measures of leakage index and microaneurysm count in the posterior pole on UWFA images were associated with the presence and severity of DME. Panretinal analyses were not linked to DME as strongly. Additional research is needed to determine the role of quantitative UWFA in predicting DME development and characterizing patient prognosis.

Distribution of Diabetic Neovascularization on Ultra-Widefield Fluorescein Angiography and on Simulated Widefield OCT Angiography

Areas of neovascularization (NV) in proliferative diabetic retinopathy (PDR) on ultra-widefield (UWF) fluorescein angiography (FA) were identified and compared with a simulated widefield (WF) swept-source OCT angiography (SS-OCTA) field of view to determine whether the WF SS-OCTA field of view was sufficient for detection of NV in PDR. Retrospective, consecutive case series. All patients with PDR and UWF FA imaging at the Bascom Palmer Eye Institute over a period of 5.5 years were identified. UWF FA images were reviewed and sites of NV were identified either as NV of the disc or NV elsewhere. Sites of NV elsewhere were classified by disc-centered retinal quadrants. A simulated WF SS-OCTA montage field of view was overlaid on the UWF FA images to determine whether sites of NV would have been identified by this simulated WF SS-OCTA field of view. A total of 651 eyes with PDR from 433 patients had at least 1UWF FA with NV. Of the 651 eyes, 50% were treatment-naïve, 9.8% had NV of the disc only, 41.8% had NV elsewhere only, and 48.4% had both NV of the disc and NV elsewhere. NV elsewhere was most prevalent in the superotemporal quadrant and the least prevalent in the nasal quadrants. When the simulated WF SS-OCTA field of view was overlaid on the UWF FA, 98.3% of all eyes, 99.4% of treatment-naive eyes, and 97.2% of previously treated eyes had NV within the WF SS-OCTA field of view. In those eyes with a repeat UWF FA within 6 to 18months of the first FA, the distribution of NV did not change in either the treatment-naive or previously treated eyes. NV elsewhere in PDR was most prevalent superotemporally, and 99.4% of treatment-naïve eyes had NV within the simulated WF SS-OCTA field of view. Combined with previous research using WF SS-OCTA to identify NV in PDR, these findings suggest that WF SS-OCTA may be the only imaging modality needed for the diagnosis and longitudinal management of PDR.

Analysis of quantitative correlations between microaneurysm, ischaemic index and new vessels in ultrawide-field fluorescein angiography images using automated software

Background/AimTo analyse ultrawide-field fluorescein angiography (UWF-FA) images of diabetic retinopathy using a novel software that automatically calculates microaneurysm (MA) and non-perfusion area.MethodsTwo hundred UWF-FA images of treatment-naïve diabetic retinopathy (38...

Ultra-Wide-Field Fluorescein Angiography–Guided Normalization of Ischemic Index Calculation in Eyes With Retinal Vein Occlusion

The purpose of this study was to compare the use of central and montaged ultra-wide-field fluorescein angiography (UWFFA) images for calculating the area of nonperfusion (NP) and ischemic index (ISI) in patients with retinal vein occlusion (RVO) and macular edema (ME) and to correlate these measurements with best-corrected visual acuity (BCVA) and central macular thickness (CMT). Thirty eyes of 30 RVO patients with recurrent ME were enrolled. Baseline UWFA images were sent to the Doheny Image Reading Center for quantitative analysis by certified graders. The association between ISI from the various zones and BCVA and CMT was examined by Spearman rank correlation and compared. Generalized linear models (GLMs) were used to analyze associations between BCVA and disease status. The NP area and ISI for central and montaged images were not significantly different for any retinal zone. A modest but statistically significant negative linear correlation was observed between BCVA and ISI, ranging from r = -0.3825 in the perimacular area (PMA) to r = -0.584 in the far peripheral area (FPA). On GLM analysis, both PMA (β = -1.059; 95% confidence interval: -1.74 to -0.378) and FPA (β = -0.505; 95% confidence interval: -0.988 to -0.021) were significant independent predictors of BCVA. We found no correlation between ISI from the various zones and CMT in this cohort. Montaging of UWFFA images may not be required to adequately quantify and represent areas of NP in eyes with RVO. NP in both the PMA and peripheral retina appear relevant to visual function, highlighting the importance of evaluating the retinal periphery in these individuals.

Association of Disorganization of Retinal Inner Layers with Ischemic Index and Visual Acuity in Central Retinal Vein Occlusion

To determine whether disorganization of retinal inner layers (DRIL) on optical coherence tomography (OCT) is associated with ischemia on ultra-widefield fluorescein angiography (UWFFA) and with visual outcomes in eyes with acute, treatment-naïve central retinal vein occlusion (CRVO). Retrospective, single-institution, longitudinal cohort study. Twenty-five consecutive patients with treatment-naïve CRVO and ≥ 1 year follow-up. Two independent masked graders evaluated the extent of DRIL, ellipsoid zone disruption, external limiting membrane disruption, and other OCT parameters at the baseline, 6- month, 12-month, and final visits. Baseline UWFFA images were assessed for ischemic index values and foveal avascular zone (FAZ) enlargement. Associations of DRIL with UWFFA findings and clinical outcomes including corrected visual acuity (VA). The median time to final follow-up was 24 months (range 12.1 - 43.9 months). Median DRIL extent at baseline was 765 µm (range 0 - 1000 µm). Eighteen of 25 eyes (72%) had some degree of DRIL at baseline, and 20 of 25 eyes (80%) had cystoid macular edema (CME). Neither the presence nor extent of DRIL at baseline was associated with presenting VA. In a cross-sectional analysis of each visit, extent of DRIL correlated with worse VA at both the 6-month (ρ = 0.656; p = 0.001) and final (ρ = 0.509; p = 0.016) visits. At final follow-up, DRIL extent was the OCT parameter most strongly correlated with baseline ischemic index (ρ = 0.418; p = 0.047) and baseline enlarged FAZ (p = 0.057) on UWFFA. On multivariate regression analysis, DRIL extent at final follow-up was the only OCT parameter associated with worse VA (p = 0.013) and remained significant when accounting for CME as a potential confounder. Extent of DRIL was not associated with presenting VA in treatment-naïve eyes with acute CRVO. Following six months of follow-up however, DRIL extent correlated with worse VA and was predictive of worse VA throughout more than 2 years of follow-up. Ischemic features on UWFFA at baseline are predictive of the extent of DRIL development at final follow-up.