Comparison of Snellen Visual Acuity Measurements in Retinal Clinical Practice to Electronic ETDRS Protocol Visual Acuity Assessment.

PURPOSE: Evaluate the differences between clinical visual acuity (VA) as recorded in medical records and electronic Early Treatment Diabetic Retinopathy Study (eETDRS) protocol VA measurements and factors affecting the size of the differences. DESIGN: Retrospective chart review. PARTICIPANTS: Study and fellow eyes of participants enrolled in DRCR Retina Network Protocols AC and AE (diabetic macular edema), and W (nonproliferative diabetic retinopathy) with clinical VA recorded within 3 months before the protocol visit. METHODS: Differences and their association with patient and ocular factors were evaluated using linear mixed models with random effects for correlations within sites and participants. MAIN OUTCOME MEASURE: Difference between VA letter scores measured by eETDRS during a study visit versus measured by Snellen during a regular clinical visit (Snellen fraction converted to eETDRS). RESULTS: Data from 1016 eyes (511 participants) across 74 sites were analyzed. The mean VA measurements were 68.6 letters (Snellen equivalent 20/50) at the clinical visit and 76.3 letters (Snellen equivalent 20/32) at the protocol visit, with a mean (standard deviation [SD]) of 26 (21) days between visits. Mean (SD) protocol VA was better than clinical VA by 7.6 (9.6) letters overall, 10.7 (12.6) letters in eyes with clinical VA ≤ 20/50 (n = 376), and 5.8 (6.6) letters in eyes with clinical VA ≥ 20/40 (n = 640). On average, the difference between clinical and protocol VA was 1.3 letters smaller for every 1-line (5 letters) increase in clinical VA (P < 0.001). Mean (SD) differences by clinical correction of refractive error were 3.9 (9.0) letters with refraction, 6.9 (9.2) letters with glasses/contact lenses, 7.9 (11.5) letters with pinhole, and 9.8 (9.3) letters without correction (P = 0.06). CONCLUSIONS: On average, clinical Snellen VA is 1 to 2 lines worse than eETDRS protocol refraction and VA testing, which may partly explain why clinical practice does not always replicate clinical trial results. Eyes with lower clinical measurements and eyes tested without clinical refraction tended to have larger differences. Considering the potential discrepancies between clinical and protocol VA measurements, refracting eyes in the clinic may benefit patients when determining treatment plans and study referrals based on vision. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Four-Year Visual Outcomes in the Protocol W Randomized Trial of Intravitreous Aflibercept for Prevention of Vision-Threatening Complications of Diabetic Retinopathy.

Importance: Anti-vascular endothelial growth factor (VEGF) injections in eyes with nonproliferative diabetic retinopathy (NPDR) without center-involved diabetic macular edema (CI-DME) reduce development of vision-threatening complications from diabetes over at least 2 years, but whether this treatment has a longer-term benefit on visual acuity is unknown. Objective: To compare the primary 4-year outcomes of visual acuity and rates of vision-threatening complications in eyes with moderate to severe NPDR treated with intravitreal aflibercept compared with sham. The primary 2-year analysis of this study has been reported. Design, Setting, and Participants: Randomized clinical trial conducted at 64 clinical sites in the US and Canada from January 2016 to March 2018, enrolling 328 adults (399 eyes) with moderate to severe NPDR (Early Treatment Diabetic Retinopathy Study [ETDRS] severity level 43-53; range, 0 [worst] to 100 [best]) without CI-DME. Interventions: Eyes were randomly assigned to 2.0 mg aflibercept (n = 200) or sham (n = 199). Eight injections were administered at defined intervals through 2 years, continuing quarterly through 4 years unless the eye improved to mild NPDR or better. Aflibercept was given in both groups to treat development of high-risk proliferative diabetic retinopathy (PDR) or CI-DME with vision loss. Main Outcomes and Measures: Development of PDR or CI-DME with vision loss (≥10 letters at 1 visit or ≥5 letters at 2 consecutive visits) and change in visual acuity (best corrected ETDRS letter score) from baseline to 4 years. Results: Among participants (mean age 56 years; 42.4% female; 5% Asian, 15% Black, 32% Hispanic, 45% White), the 4-year cumulative probability of developing PDR or CI-DME with vision loss was 33.9% with aflibercept vs 56.9% with sham (adjusted hazard ratio, 0.40 [97.5% CI, 0.28 to 0.57]; P < .001). The mean (SD) change in visual acuity from baseline to 4 years was -2.7 (6.5) letters with aflibercept and -2.4 (5.8) letters with sham (adjusted mean difference, -0.5 letters [97.5% CI, -2.3 to 1.3]; P = .52). Antiplatelet Trialists' Collaboration cardiovascular/cerebrovascular event rates were 9.9% (7 of 71) in bilateral participants, 10.9% (14 of 129) in unilateral aflibercept participants, and 7.8% (10 of 128) in unilateral sham participants. Conclusions and Relevance: Among patients with NPDR but without CI-DME at 4 years treatment with aflibercept vs sham, initiating aflibercept treatment only if vision-threatening complications developed, resulted in statistically significant anatomic improvement but no improvement in visual acuity. Aflibercept as a preventive strategy, as used in this trial, may not be generally warranted for patients with NPDR without CI-DME. Trial Registration: ClinicalTrials.gov Identifier: NCT02634333.

Five-Year Outcomes after Initial Aflibercept, Bevacizumab, or Ranibizumab Treatment for Diabetic Macular Edema (Protocol T Extension Study).

PURPOSE: Assess follow-up treatment and clinical outcomes at 5 years in eyes initially treated with anti-VEGF therapy for center-involved diabetic macular edema (CI-DME) in a 2-year randomized clinical trial. DESIGN: Multicenter cohort study. PARTICIPANTS: Participants with diabetic macular edema (DME) and visual acuity (VA) 20/32 to 20/320 enrolled in DRCR.net Protocol T with visits 5 years after randomization (3 years after Protocol T completion). METHODS: Participants were assigned randomly to aflibercept, bevacizumab, or ranibizumab with protocol-defined follow-up and re-treatment for 2 years. Thereafter, participants were managed at clinician discretion and recalled for a 5-year visit. MAIN OUTCOME MEASURES: Anti-vascular endothelial growth factor (VEGF) treatment, VA letter score, and central subfield thickness (CST). RESULTS: Sixty-eight percent (317/463) of eligible participants completed the 5-year visit. Between years 2 and 5, 68% (217/317) of study eyes received at least 1 anti-VEGF treatment (median, 4; interquartile range [IQR], 0-12). At 5 years, mean VA improved from baseline by 7.4 letters (95% confidence interval [CI], 5.9-9.0) but decreased by 4.7 letters (95% CI, 3.3-6.0) between 2 and 5 years. When baseline VA was 20/50 to 20/320, mean 5-year VA was 11.9 letters (95% CI, 9.3-14.5) better than baseline but 4.8 letters (95% CI, 2.5-7.0) worse than 2 years. When baseline VA was 20/32 to 20/40, mean 5-year VA was 3.2 letters (95% CI, 1.4-5.0) better than baseline but 4.6 letters (95% CI, 3.1-6.1) worse than 2 years. Mean CST decreased from baseline to 5 years by 154 µm (95% CI, 142-166) and was stable between 2 and 5 years (-1 µm; 95% CI, -12 to 9). CONCLUSIONS: Among the two-thirds of eligible Protocol T participants who completed a 5-year visit, mean VA improved from baseline to 5 years without protocol-defined treatment after follow-up ended at 2 years. Although mean retinal thickness was similar at 2 and 5 years, mean VA worsened during this period. Additional investigation into strategies to improve long-term outcomes in eyes with DME seems warranted to determine if VA can be better maintained with different management approaches.

Assessment of Baseline Ultrawidefield Fluorescein Angiographic Quantitative Leakage Parameters with Ultrawidefield Fundus Features and Clinical Parameters in Diabetic Retinopathy in Protocol AA.

PURPOSE: Evaluate quantitative leakage parameters on ultrawidefield fluorescein angiography (UWF-FA) images and explore their association with Diabetic Retinopathy Severity Scale (DRSS), predominantly peripheral lesions (PPLs), visual acuity, and clinical characteristics. DESIGN: A post hoc analysis of baseline UWF-FA images in the DRCR Retina Network observational study Protocol AA. PARTICIPANTS: A total of 575 eyes from 384 adults across 38 sites in the United States and Canada with gradable UWF-FA. METHODS: A machine learning-enhanced feature extraction platform provided initial leakage segmentation of UWF-FA images sequentially reviewed and corrected by 2 certified readers for segmentation accuracy. Ultrawidefield fluorescein angiography leakage was measured in 5 retinal zones: panretinal (entire retina), central macular (3-disc diameter fovea-centered circle), posterior pole (6-disc diameter fovea-centered circle), peripheral (outside 6-disc diameter circle), and widefield far peripheral (outside 9-disc diameter circle); associations with clinical factors were evaluated with marginal beta regression models. MAIN OUTCOME MEASURES: Ultrawidefield fluorescein angiography leakage index, calculated as the area with leakage divided by the analyzable retinal area. RESULTS: The mean quantitative leakage index was 3.5% for panretinal, 6.6% for macular, 4.8% for posterior pole, 3.3% for peripheral, and 2.8% for widefield far peripheral retinal zones. Panretinal leakage was associated with DRSS (mean 2.2% for no to mild nonproliferative diabetic retinopathy [NPDR], 3.4% for moderate NPDR, 4.2% for moderately severe NPDR, 4.8% for severe NPDR, and 5.1% for proliferative diabetic retinopathy; P < 0.001), hemoglobin A1C (HbA1c) (3.2% for HbA1c < 8% vs. 3.8% for HbA1c ≥ 8%; P = 0.01 for continuous HbA1c), visual acuity (3.3% for 20/25 or better vs. 4.7% for 20/32 or worse; continuous P < 0.001), and UWF-FA-PPL types of intraretinal microvascular abnormality (4.3% vs. 3.3%; P = 0.005) or new vessels elsewhere (5.7% vs. 3.4%; P = 0.003). Diabetic retinopathy severity was also statistically significant for leakage within all retinal zones (P < 0.001); eyes with noncentral diabetic macular edema (DME) versus no DME had higher mean leakage in the central macular (11.2% vs. 5.9%; P = 0.005) and posterior pole regions (9.2% vs. 4.2%; P = 0.002). CONCLUSIONS: Quantitative UWF-FA leakage analysis identified associations between leakage and DRSS, visual acuity, and presence of DME. In the future, quantitative UWF-FA leakage parameters may be explored as potential biomarkers for disease progression risk. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Long-Term Effects of Intravitreal Ranibizumab Compared With Panretinal Photocoagulation on Optical Coherence Tomography Measured Choroidal Thickness and Vascularity.

Purpose: Compare choroidal changes in ranibizumab versus panretinal photocoagulation (PRP)-treated eyes with proliferative diabetic retinopathy (PDR). Methods: DRCR Retina Network Protocol S post hoc analysis evaluated optical coherence tomography change in choroidal thickness (subfoveal and 3mm superior and inferior to the fovea) through five years; choroidal vascularity index (CVI) was assessed at baseline and one year. Mixed linear models for choroidal change included adjustments for the baseline choroidal value and age. Results: This study included 328 eyes (158 ranibizumab and 170 PRP) from 256 participants (88 ranibizumab and 95 PRP eyes at five years). Mean change in choroidal thickness from baseline to five years at the fovea was -12 µm in ranibizumab versus -8 µm in PRP (difference [95% confidence interval]: -4 [-18 to 10], P = 0.57), superior was -14 µm versus -19 µm (difference: 5 [-8 to 17], P = 0.45) and inferior was -26 µm versus -32 µm [difference: 5 (-9 to 20), P = 0.45]; change at all three points within the ranibizumab group, and the superior and inferior points for PRP, were statistically significant (P < .05). Mean change in CVI at one year was -0.02% in ranibizumab versus -0.95% in PRP (difference: 0.93 [-0.35 to 2.21], P = 0.14). Conclusions: In patients with PDR, treatment with ranibizumab versus PRP did not result in statistically significant differences in five-year choroidal thickness or one-year CVI change. Both groups had significant decreases in choroidal thickness at five years. Translational Relevance: Ranibizumab treatment for PDR did not statistically significantly affect choroidal thickness or vascularity differently than PRP.

A Randomized Trial of Photobiomodulation Therapy for Center-Involved Diabetic Macular Edema with Good Visual Acuity (Protocol AE).

PURPOSE: To determine if treatment with a photobiomodulation (PBM) device results in greater improvement in central subfield thickness (CST) than placebo in eyes with center-involved diabetic macular edema (CI-DME) and good vision. DESIGN: Phase 2 randomized clinical trial. PARTICIPANTS: Participants had CI-DME and visual acuity (VA) 20/25 or better in the study eye and were recruited from 23 clinical sites in the United States. METHODS: One eye of each participant was randomly assigned 1:1 to a 670-nm light-emitting PBM eye patch or an identical device emitting broad-spectrum white light at low power. Treatment was applied for 90 seconds twice daily for 4 months. MAIN OUTCOME MEASURES: Change in CST on spectral-domain OCT at 4 months. RESULTS: From April 2019 to February 2020, 135 adults were randomly assigned to either PBM (n = 69) or placebo (n = 66); median age was 62 years, 37% were women, and 82% were White. The median device compliance was 92% with PBM and 95% with placebo. OCT CST increased from baseline to 4 months by a mean (SD) of 13 (53) µm in PBM eyes and 15 (57) µm in placebo eyes, with the mean difference (95% confidence interval [CI]) being -2 (-20 to 16) µm (P = 0.84). CI-DME, based on DRCR Retina Network sex- and machine-based thresholds, was present in 61 (90%) PBM eyes and 57 (86%) placebo eyes at 4 months (adjusted odds ratio [95% CI] = 1.30 (0.44-3.83); P = 0.63). VA decreased by a mean (SD) of -0.2 (5.5) letters and -0.6 (4.6) letters in the PBM and placebo groups, respectively (difference [95% CI] = 0.4 (-1.3 to 2.0) letters; P = 0.64). There were 8 adverse events possibly related to the PBM device and 2 adverse events possibly related to the placebo device. None were serious. CONCLUSIONS: PBM as given in this study, although safe and well-tolerated, was not found to be effective for the treatment of CI-DME in eyes with good vision.

Effect of Intravitreous Anti-Vascular Endothelial Growth Factor vs Sham Treatment for Prevention of Vision-Threatening Complications of Diabetic Retinopathy: The Protocol W Randomized Clinical Trial.

IMPORTANCE: The role of anti-vascular endothelial growth factor injections for the management of nonproliferative diabetic retinopathy (NPDR) without center-involved diabetic macular edema (CI-DME) has not been clearly established. OBJECTIVE: To determine the efficacy of intravitreous aflibercept injections compared with sham treatment in preventing potentially vision-threatening complications in eyes with moderate to severe NPDR. DESIGN, SETTING, AND PARTICIPANTS: Data for this study were collected between January 15, 2016, and May 28, 2020, from the ongoing DRCR Retina Network Protocol W randomized clinical trial, conducted at 64 US and Canadian sites among 328 adults (399 eyes) with moderate to severe NPDR (Early Treatment Diabetic Retinopathy Study severity level, 43-53), without CI-DME. Analyses followed the intent-to-treat principle. INTERVENTIONS: Eyes were randomly assigned to 2.0 mg of aflibercept injections (n = 200) or sham (n = 199) given at baseline; 1, 2, and 4 months; and every 4 months through 2 years. Between 2 and 4 years, treatment was deferred if the eye had mild NPDR or better. Aflibercept was administered in both groups if CI-DME with vision loss (≥10 letters at 1 visit or 5-9 letters at 2 consecutive visits) or high-risk proliferative diabetic retinopathy (PDR) developed. MAIN OUTCOMES AND MEASURES: Development of CI-DME with vision loss or PDR through May 2020, when the last 2-year visit was completed. RESULTS: Among the 328 participants (57.6% men [230 of 399 eyes]; mean [SD] age, 56 [11] years), the 2-year cumulative probability of developing CI-DME with vision loss or PDR was 16.3% with aflibercept vs 43.5% with sham. The overall hazard ratio for either outcome was 0.32 (97.5% CI, 0.21-0.50; P < .001), favoring aflibercept. The 2-year cumulative probability of developing PDR was 13.5% in the aflibercept group vs 33.2% in the sham group, and the 2-year cumulative probability of developing CI-DME with vision loss was 4.1% in the aflibercept group vs 14.8% in the sham group. The mean (SD) change in visual acuity from baseline to 2 years was -0.9 (5.8) letters with aflibercept and -2.0 (6.1) letters with sham (adjusted mean difference, 0.5 letters [97.5% CI, -1.0 to 1.9 letters]; P = .47). CONCLUSIONS AND RELEVANCE: In this randomized clinical trial, among eyes with moderate to severe NPDR, the proportion of eyes that developed PDR or vision-reducing CI-DME was lower with periodic aflibercept compared with sham treatment. However, through 2 years, preventive treatment did not confer visual acuity benefit compared with observation plus treatment with aflibercept only after development of PDR or vision-reducing CI-DME. The 4-year results will be important to assess longer-term visual acuity outcomes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02634333.

Conversion of Central Subfield Thickness Measurements of Diabetic Macular Edema Across Cirrus and Spectralis Optical Coherence Tomography Instruments.

Purpose: Develop equations to convert Cirrus central subfield thickness (CST) to Spectralis CST equivalents and vice versa in eyes with diabetic macular edema (DME). Methods: The DRCR Retina Network Protocol O data were split randomly to train (70% sample) and validate (30% sample) conversion equations. Data from an independent study (CADME) also validated the equations. Bland-Altman 95% limits of agreement between predicted and observed values evaluated the equations. Results: Protocol O included 374 CST scan pairs from 187 eyes (107 participants). The CADME study included 150 scan pairs of 37 eyes (37 participants). Proposed conversion equations are Spectralis = 40.78 + 0.95 × Cirrus and Cirrus = 1.82 + 0.94 × Spectralis regardless of age, sex, or CST. Predicted values were within 10% of observed values in 101 (90%) of Spectralis and 99 (88%) of Cirrus scans in the validation data; and in 136 (91%) of the Spectralis and 148 (99%) of the Cirrus scans in the CADME data. Adjusting for within-eye correlations, 95% of conversions are estimated to be within 17% (95% confidence interval, 14%-21%) of CST on Spectralis and within 22% (95% confidence interval, 18%-28%) of CST on Cirrus. Conclusions: Conversion equations developed in this study allow the harmonization of CST measurements for eyes with DME using a mix of current Cirrus and Spectralis device images. Translational Relevance: The CSTs measured on Cirrus and Spectralis devices are not directly comparable owing to outer boundary segmentation differences. Converting CST values across spectral domain optical coherence tomography instruments should benefit both clinical research and standard care efforts.