Ultra-widefield Imaging System Research Articles

Comparison of Standard 7-Field, Clarus, and Optos Ultrawidefield Imaging Systems for Diabetic Retinopathy (COCO Study)

The purpose of this study was to compare diabetic retinopathy (DR) severity levels assessed from 7 standard-field stereoscopic color photographs on a 35° fundus camera to both Clarus and Optos ultrawidefield color images. Cross-sectional, comparative imaging study. Participants with DR imaged at a single-center retina practice. Participants were imaged on 3 cameras at a single visit with the Topcon 35° fundus camera, Clarus, and Optos. The DR Severity Scale (DRSS) level was determined within the 7-field (7F) area of each image set using the ETDRS scale. An additional global DRSS was assigned for both Clarus and Optos images using the entire visible retina. Weighted kappa (wκ) measured the agreement between cameras. The primary outcome was a 3-way comparison of DRSS level within the 7F area imaged on the 3 cameras. Secondary outcomes included a comparison of the DRSS obtained with standard 7F imaging to the global DRSS of Clarus and Optos and a comparison of the global DRSS between Clarus and Optos only. Ninety-seven eyes (50 participants) were evaluated. Agreement within 1-step of ETDRS levels between standard 7F imaging and Clarus 7F was 90.1% (wκ=0.65), and with Optos 7F in 85.9%, (wκ=0.58). Agreement within 1-step between standard 7F imaging and Clarus global was 88.9% of eyes (wκ=0.63), and Optos global was 85.7%, (wκ=0.54). Agreement between Clarus and Optos global DR level within 1-step was 89.1% (wκ=0.68). Intergrader agreement for the 7F ETDRS level was 96% for standard 7F imaging, 98% for Clarus, and 95.5% for Optos. These findings suggest that when evaluating the 7F area on Clarus and Optos, DR severity grades are comparable to standard 7F imaging. However, it is important to understand the unique attributes and differences of each fundus camera when changing the type of system used in a clinical setting due to upgrading equipment. Additionally, if the facility has access to > 1 device, there should not be an exchange between cameras for the same patient. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Comparison of Clarus and Optomap Ultra-Widefield Imaging Systems before and after EVO-ICL Implantation in High Myopia

Introduction: The aim of this study was to investigate the features of imaging differences between Clarus and Optomap ultra-widefield imaging systems after implantable collamer lens (ICL) implantation. Methods: This was a non-randomized controlled study. Ninety-two eyes of 46 consecutive patients were enrolled. Full-scale ophthalmological examinations were conducted preoperatively. All patients underwent Clarus (CLARUS 500; Carl Zeiss, Dublin, USA) and Optomap (Daytona; Optos, UK) ultra-wide imaging sequentially under the same circumstance preoperatively and 1 month after EVO-ICL implantation. A single image was acquired from each. Dx was defined as the distance between the upper furcation of the central retinal artery and the central fovea of macula. Pixels of the optic cup and disc and Dx as well as the optic cup/disc ratio were calculated and compared on each machine before and after surgery. Results: All surgeries were uneventful without complications. Safety and efficacy indices were both 100% at 1 month. Values of both optic cup and disc areas were in decrease after surgery with statistically significant differences (p < 0.001), while the cup/disc ratio remained the same (Clarus mean of differences = −0.0028, p = 0.83; Optomap mean of differences = −0.0016, p = 0.76). Dx of images captured with either machine was statistically significantly decreased (p < 0.001). Differences of both optic cup (p = 0.057) and disc (p = 0.041) areas of Clarus were more obvious than that of Optomap, while only the latter was with statistical significance. Difference of Dx of Clarus was statistically significantly larger than Optomap. Conclusions: Display ranges tend to be broadened after EVO-ICL implantation in both Clarus and Optomap ultra-widefield imaging systems, while Clarus shows a wider display range of the two, which encourages the application of Clarus when it comes to the detection of more peripheral retinal lesions.

Randomized, Comparative Study of Full- and Half-Dose Fluorescein Angiography.

This study determines whether fluorescein angiography (FA) with a 250-mg dose of fluorescein (half dose) is equal in quality to the standard 500-mg dose of fluorescein (full dose) when using digital ultra-widefield (UWF) technology. In a randomized, prospective study using a UWF imaging system, FAs performed with half dose were compared with angiograms performed with full dose. Imaging studies were reviewed by 4 reviewers based on 6 characteristics: dye transit, macrovasculature, macula detail, microvasculature, leakage, and overall quality. The scores for macrovasculature, macula detail, microvasculature, and overall quality were converted to a fuzzy rating score to confirm results. Seventy-nine FAs from 67 patients were reviewed for this study, including 12 patients who had both half-dose and full-dose FAs. Of all the factors studied, only microvasculature received a significantly different score between full dose and half dose that was confirmed by the fuzzy rating scale (3.79 vs 3.53; P = .04). Among those eyes that received both full and half dose, there was no significant difference in any of the 6 factors. In a UWF imaging system, aside from looking at fine microvascular abnormalities, the 250-mg dose of fluorescein provided similar results to a 500-mg dose. The images were not significantly different in overall quality.

Efficacy of the Newly Invented Eyelid Clamper in Ultra-Widefield Fundus Imaging.

Background: Ultra-widefield fundus imaging is widely used for obtaining wide angle images of the retina in one single image. Although it has a potential to obtain a wide area of retinal photographs, images are often obstructed by eyelashes or eye lids. In this study, we used a newly invented eyelid clamper, which can keep an eye open without touching conjunctiva or lid margin, to assess the efficacy in clinical use by comparing with conventional tape fixation. Methods: Ultra-widefield fundus images were captured with an ultra-widefield imaging system in 19 patients who visited to the outpatient clinic of Department of Ophthalmology, Keio University Hospital with the eyelid clamper or a conventional tape fixation. The area of imaged retinas was outlined and quantified with pixels. After obtaining images, patients answered a questionnaire. Results: The average number of pixels in total areas with the eyelid clamper or with tape fixation were 4.31 ± 0.35 and 4.32 ± 0.34 mega pixels, respectively, showing no significant difference between the groups (p = 0.889). The average face pain scale of the eyelid clamper was 1.13 on a scale of 0 to 5. The number of patients who did not feel any pain was nine (47.4%). Conclusions: The eyelid clamper can be applied in clinical setting and can better support obtaining sufficiently wide fundus images compared to a conventional tape fixation.

UTILITY OF ORAL FLUORESCEIN ANGIOGRAPHY WITH ULTRA-WIDEFIELD IMAGING SYSTEM FOR EVALUATION OF VARIOUS RETINAL DISORDERS.

To evaluate the utility of oral fluorescein angiography with ultra-widefield imaging system (oral UWF-FA) predominantly in children. We recruited 17 patients aged 2 years to 22 years with retinal disorders. Each patient ingested a dose of fluorescein sodium set by body weight mixed with 100 mL of juice. Images were scored using four parameters as follows: branch retinal vessel identification, retinal vessels visualization, foveal avascular zone visualization, and clinically important findings such as leakage, microaneurysms, neovascularization, or significant nonperfusion area visualization. Based on the aggregate score, we classified the image quality into three grades. Sixteen of 17 patients completely ingested the fluorescein sodium, and ultra-widefield fluorescein angiography was performed. Images were classified as high quality in nine cases, moderate quality in four, and poor quality in three. In 13 cases (81.3%), images had adequate quality to evaluate retinal conditions. Of three patients with poor-quality images, 2 took 10 minutes to ingest fluorescein sodium and the other ingested only half the dose. The adverse event of a mild skin rash was noted in one patient. Oral ultra-widefield fluorescein angiography is effective in evaluating retinal pathology and is a useful alternative especially for pediatric patients who cannot tolerate intravenous line placement.

Clinical application of ultra-widefield fundus autofluorescence.

To review the basic principles of ultra-widefield fundus autofluorescence (UWF-FAF) and discuss its clinical application for a variety of retinal and choroidal disorders. A systematic review of the PubMed database was performed using the search terms "ultra-widefield," "autofluorescence," "retinal disease" and "choroidal disease." UWF-FAF imaging is a recently developed noninvasive retinal imaging modality with a wide imaging range that can locate peripheral fundus lesions that traditional fundus autofluorescence cannot. Multiple commercially available ultra-widefield imaging systems, including Heidelberg Spectralis and Optomap Ultra-Widefieldsystems, are available to the clinician. Imaging by UWF-FAF is more comprehensive; it can reflect the content and distribution of the predominant ocular fluorophore in retinal pigment epithelial cells and evaluate the metabolic status of RPE of various retinal and choroidal disorders. UWF-FAF can detect abnormalities that traditional fundus autofluorescence cannot; therefore, it can be used to better elucidate disease pathogenesis, analyze genotype-phenotype correlations, diagnose and monitor disease.

Ultra-widefield retinal imaging: an update on recent advances.

The development of ultra-widefield retinal imaging has accelerated our understanding of common retinal diseases. As we continue to validate the diagnostic and prognostic significance of pathology in the retinal periphery, the ability to visualize and evaluate these features in an efficient and patient-friendly manner will become more important. Current interest in ultra-widefield imaging includes the development of potential biomarkers of disease progression and indicators of preclinical disease development. This article reviews the current ultra-widefield imaging systems and recent advances in their applications to clinical practice with a focus on diabetic retinopathy, retinal vein occlusion, uveitis, and pediatric retina.

WIDEFIELD SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY IMAGING OF PERIPHERAL ROUND RETINAL HOLES WITH OR WITHOUT RETINAL DETACHMENT.

To describe the widefield spectral-domain optical coherence tomography features of peripheral round retinal holes, with or without associated retinal detachment (RD). Retrospective, observational study of 28 eyes with peripheral round retinal holes, with and without RD. Patients underwent imaging with a widefield 50-degree spectral-domain optical coherence tomography (Heidelberg Engineering, Germany) and Optos ultra-widefield imaging systems (Optos, United Kingdom). Vitreous attachment at the site of the retinal hole was detected in 27/28 (96.4%) cases. Cases were split into three groups: RHs with RD (n = 12); RHs with subretinal fluid (n = 5), and flat RHs (n = 11), with minimal or no subretinal fluid. 91.6% retinal holes associated with subretinal fluid or RD had vitreous attachment at the site of the hole. Eighty percent had vitreous attachment at both edges of the retinal hole, in a U-shape configuration, which appeared to exert traction. By contrast, flat retinal holes had visible vitreous attachment only at one edge of the retinal hole in 45.4%. Vitreous attachment was commonly seen at the site of round retinal holes. Vitreous attachment at both edges of the retinal hole in a U-shape configuration was more commonly seen at holes associated with subretinal fluid or RD.

Comparison of Early Treatment Diabetic Retinopathy Study Standard 7-Field Imaging With Ultrawide-Field Imaging for Determining Severity of Diabetic Retinopathy

Moderate to substantial agreement between Early Treatment Diabetic Retinopathy Study (ETDRS) 7-field imaging and ultrawide-field (UWF) imaging has been suggested in single-center studies. Comparing images obtained by multiple centers could increase confidence that UWF images can be used reliably in place of ETDRS imaging in future clinical trials. To compare diabetic retinopathy (DR) severity from modified ETDRS 7-field imaging and UWF imaging. This preplanned, cross-sectional analysis included modified ETDRS 7-field images obtained using the Diabetic Retinopathy Clinical Research Network acquisition protocol and UWF images obtained captured with the Optos 200Tx system (Optos, PLC) from adult participants (≥18 years old) with type 1 or type 2 diabetes. Both image types were evaluated by trained graders masked to clinical data. Data collection occurred from February 2015 to December 2015, and data analysis from June 2016 to December 2017. Agreement between UWF images, UWF images masked to include only the ETDRS 7-field area, and ETDRS 7-field images were calculated using κ statistics. A total of 764 eyes from 385 participants were included; participants had a median (IQR) age of 62.2 (53.6-69.2) years, 194 (50.4%) were women, and 256 (66.5%) were white. Of 742 eyes with both ETDRS 7-field images and UWF masked images graded, 359 (48.4% [95% CI, 44.4%-52.4%]) eyes had exact agreement, and 653 eyes (88.0% [95% CI, 85.2%-90.3%]) agreed within 1 step (weighted κ, 0.51 [95% CI, 0.44-0.58]). After open adjudication by an independent senior grader of all images with more than a 2-step discrepancy, perfect agreement was found in 435 eyes (59.0% [95% CI, 55.1%-62.8%]) and agreement within 1 step in 714 eyes (96.9% [95% CI, 95.1%-98.0%]; κ, 0.77 [95% CI, 0.73-0.82]). Ability of the imaging modalities to detect retinopathy severity in an individual eye was considered similar in 59 eyes (50.9% [95% CI, 41.3%-60.4%]), better for ETDRS 7-field imaging in 22 eyes (19.0% [95% CI, 12.5%-27.7%]), and better for UWF-masked images in 31 eyes (26.7% [95% CI 18.8%-36.5%]). Comparing UWF masked and unmasked images, 94 of 751 eyes (12.5%) had DR graded as at least 1 step more severe on UWF unmasked images vs UWF masked images. Predominantly peripheral DR lesions were present in 308 of 751 eyes (41.0%); this suggested increased DR severity by 2 or more steps in 34 eyes (11.0%). Imaging by the ETDRS 7-field and UWF imaging systems have moderate to substantial agreement when determining the severity of DR within the 7 standard fields. Disparities in an individual eye are equivalently distributed between imaging modalities and can be better or worse on 1 or the other. Longitudinal follow-up will evaluate the primary outcome of this study to determine if peripheral retinal findings are associated with future retinopathy outcomes.

Comparison of ultra-widefield fluorescein angiography with the Heidelberg Spectralis&amp;reg; noncontact ultra-widefield module versus the Optos&amp;reg; Optomap&amp;reg;

PurposeTo compare ultra-widefield fluorescein angiography imaging using the Optos® Optomap® and the Heidelberg Spectralis® noncontact ultra-widefield module.MethodsFive patients (ten eyes) underwent ultra-widefield fluorescein angiography using the Optos® panoramic P200Tx imaging system and the noncontact ultra-widefield module in the Heidelberg Spectralis® HRA+OCT system. The images were obtained as a single, nonsteered shot centered on the macula. The area of imaged retina was outlined and quantified using Adobe® Photoshop® C5 software. The total area and area within each of four visualized quadrants was calculated and compared between the two imaging modalities. Three masked reviewers also evaluated each quadrant per eye (40 total quadrants) to determine which modality imaged the retinal vasculature most peripherally.ResultsOptos® imaging captured a total retinal area averaging 151,362 pixels, ranging from 116,998 to 205,833 pixels, while the area captured using the Heidelberg Spectralis® was 101,786 pixels, ranging from 73,424 to 116,319 (P = 0.0002). The average area per individual quadrant imaged by Optos® versus the Heidelberg Spectralis® superiorly was 32,373 vs 32,789 pixels, respectively (P = 0.91), inferiorly was 24,665 vs 26,117 pixels, respectively (P = 0.71), temporally was 47,948 vs 20,645 pixels, respectively (P = 0.0001), and nasally was 46,374 vs 22,234 pixels, respectively (P = 0.0001). The Heidelberg Spectralis® was able to image the superior and inferior retinal vasculature to a more distal point than was the Optos®, in nine of ten eyes (18 of 20 quadrants). The Optos® was able to image the nasal and temporal retinal vasculature to a more distal point than was the Heidelberg Spectralis®, in ten of ten eyes (20 of 20 quadrants).ConclusionThe ultra-widefield fluorescein angiography obtained with the Optos® and Heidelberg Spectralis® ultra-widefield imaging systems are both excellent modalities that provide views of the peripheral retina. On a single nonsteered image, the Optos® Optomap® covered a significantly larger total retinal surface area, with greater image variability, than did the Heidelberg Spectralis® ultra-widefield module. The Optos® captured an appreciably wider view of the retina temporally and nasally, albeit with peripheral distortion, while the ultra-widefield Heidelberg Spectralis® module was able to image the superior and inferior retinal vasculature more peripherally. The clinical significance of these findings as well as the area imaged on steered montaged images remains to be determined.