Clinical OphthalmologyDovepressopen access to scientific and medical researchO r i g i nal Resea r chOpen Access Full Text ArticleComparison of ultra-widefield fluoresceinangiography with the Heidelberg Spectralis noncontact ultra-widefield module versusthe Optos Optomap This article was published in the following Dove Press journal:Clinical Ophthalmology20 February 2013Number of times this article has been viewedMatthew T WitmerGeorge ParlitsisSarju PatelSzilárd KissDepartment of Ophthalmology, WeillCornell Medical College, New York,NY, USACorrespondence: Szilárd Kiss; MatthewT WitmerWeill Cornell Medical College,Department of Ophthalmology,1305 York Ave, 11th Floor, New York,NY 10021, USATel 1 646 962 2020Fax 1 646 962 0602Email mit your manuscript 7/OPTH.S41731Purpose: To compare ultra-widefield fluorescein angiography imaging using the Optos Optomap and the Heidelberg Spectralis noncontact ultra-widefield module.Methods: Five patients (ten eyes) underwent ultra-widefield fluorescein angiography using theOptos panoramic P200Tx imaging system and the noncontact ultra-widefield module in theHeidelberg Spectralis HRA OCT system. The images were obtained as a single, nonsteeredshot 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 wascalculated and compared between the two imaging modalities. Three masked reviewers alsoevaluated each quadrant per eye (40 total quadrants) to determine which modality imaged theretinal vasculature most peripherally.Results: Optos imaging captured a total retinal area averaging 151,362 pixels, rangingfrom 116,998 to 205,833 pixels, while the area captured using the Heidelberg Spectralis was101,786 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), temporallywas 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 of20 quadrants). The Optos was able to image the nasal and temporal retinal vasculature to a moredistal point than was the Heidelberg Spectralis , in ten of ten eyes (20 of 20 quadrants).Conclusion: The ultra-widefield fluorescein angiography obtained with the Optos and Heidelberg Spectralis ultra-widefield imaging systems are both excellent modalities that provideviews of the peripheral retina. On a single nonsteered image, the Optos Optomap covereda significantly larger total retinal surface area, with greater image variability, than did theHeidelberg Spectralis ultra-widefield module. The Optos captured an appreciably wider viewof the retina temporally and nasally, albeit with peripheral distortion, while the ultra-widefieldHeidelberg Spectralis module was able to image the superior and inferior retinal vasculaturemore peripherally. The clinical significance of these findings as well as the area imaged onsteered montaged images remains to be determined.Keywords: peripheral, retina, wide-angle, widefield, ultra-widefieldIntroductionAs the site of considerable pathology, visualization of the peripheral retina has becomeessential to the screening, diagnosis, monitoring, and treatment of many visionthreatening eye diseases, including diabetic retinopathy.Clinical Ophthalmology 2013:7 389–394389 2013 Witmer et al, publisher and licensee Dove Medical Press Ltd. This is an Open Access articlewhich permits unrestricted noncommercial use, provided the original work is properly cited.
DovepressWitmer et alThe first commercially available fundus camera wasproduced in 1926 by the Carl Zeiss Company and provideda 20-degree field of view of the retina.1 Later, 30-degreesbecame the “standard” field of view. As fundus cameraswith up to 50-degrees field of view emerged, they becamewidely used in clinical practice. Consequently, imagingangles larger than 30- or 50-degrees have been referred toas “wide-field” or “wide-angle.” More recently, the term“ultra-widefield” fundus imaging has gained popularity,although the exact definition and area of the retina imagedremains ambiguous.Several imaging platforms have been developed thatprovide a widefield view of the retina. These include thePomerantzeff camera,2 the Retcam (Clarity Medical Systems,Inc, Pleasanton, CA, USA), the Panoret-1000 camera(Medibell Medical Vision Technologies, Haifa, Israel),the Optos camera (Optos PLC, Dunfermline, UK), theStaurenghi lens (Ocular Staurenghi 230 SLO Retina Lens;Ocular Instruments Inc, Bellevue, WA, USA),3 and otherwide-angle contact lenses,4–6 among others. The single-shot,nonsteered widefield imaging capabilities of these modalitiesrange from 20 degrees up to 200 degrees, albeit with variableimage quality.Ultra-widefield imaging has been shown to be valuablefor the evaluation of several retinal pathologies,7 includingdiabetes,8,9 retinal vein occlusions,10 choroidal masses,11,12uveitis,13 retinal vasculitis,14 retinal detachment,12,15 andretinopathy of prematurity,16 among others.One of the most widely used commercially availableultra-widefield systems is the Optos noncontact camera.The Optos system utilizes an ellipsoid mirror to produceimages with approximately 200 internal degrees of view,providing an image of more than 80% of the retina in asingle shot.17 This allows for simultaneous evaluation of theperipheral and central retina without the requirement of significant eye steering. Despite its ability to produce dynamicwidefield fundus images, the Optos Optomap has severallimitations. Specifically, its imaging of the far superior andinferior peripheral retina is less complete compared with itsimaging of the temporal and nasal retina.18 Moreover, thereis noteworthy distortion and decreased resolution of the fartemporal and nasal peripheral retina. A method for correctingfor this peripheral distortion, when evaluating retinal area andmaking measurements, has been described.19More recently, Heidelberg Engineering (Heidelberg,Germany) has developed a noncontact ultra-widefieldangiography module for the Spectralis and HeidelbergRetina Angiograph (HRA 2). Previously, the Heidelberg390submit your manuscript www.dovepress.comDovepressSpectralis provided a 25- and 35-degree field of view ofthe retina, with the possibility of a 55-degree noncontactlens attachment, to produce autofluorescence, fluorescein,and indocyanine green angiographic images. In addition,there was the capability of using the Staurenghi contactlens in conjunction with the Spectralis to provide up to150-degrees field of view in a single shot. The newly developed Heidelberg ultra-widefield angiography module consistsof an interchangeable noncontact lens that attaches to thecamera head to provide high-contrast, undistorted and evenlyilluminated images out to the peripheral retina. Both fluorescein and indocyanine green angiography, individually orsimultaneously, may be performed with this ultra-widefieldHeidelberg Spectralis module.With the expanded indications for ultra-widefield imaging and the varying definitions of the exact area of retinaimaged, comparison of various imaging platforms is becoming increasingly important. The purpose of this study was toreport our initial experience with a Heidelberg Spectralis noncontact, ultra-widefield module and to evaluate the area ofthe retina imaged on ultra-widefield fluorescein angiographywith the Heidelberg Spectralis compared with the Optos Optomap .MethodsThis retrospective, observational study was performed afterobtaining Institutional Review Board approval at WeillCornell Medical College in New York, NY, USA.Five patients (ten eyes) underwent nonsteered ultrawidefield fluorescein angiography using the Optos panoramic P200Tx imaging system as well as the ultra-widefieldmodule for the Heidelberg Spectralis HRA OCT module.All photographs were centered on the macula.All the images were subsequently transferred into Adobe Photoshop C5 software (Adobe Systems Inc, San Jose, CA,USA) and independently analyzed by two masked, trainedreaders (MW and GP). Using the software, each image wassplit into four quadrants centered on the fovea (Figure 1). Thearea of visible retina in each image was outlined. A free-styleline was made, demarcating the area of visible peripheralretina in each image. This area was then highlighted, and itspixels were quantified using the pixel measurement functionof the Adobe Photoshop C5 software. An additional grader(SK) verified the outline of the imaged retina for all eyes.The total area visualized, as well as the area within eachindividual quadrant (superior, inferior, nasal, and temporal)(Figure 1), was calculated and compared between the two imaging modalities. Subsequently, the images from each eye in theClinical Ophthalmology 2013:7
DovepressUltra-widefield angiographyTable 1 Total area of retina visualized on a single-shot,nonsteered imagePatientEyeOptos Optomap HeidelbergSpectralis 995105,483104,485104,201101,786*10,8202Figure 1 Fluorescein angiogram of the right eye of a patient showing a singleshot, noncontact image centered on the macula. (A) Heidelberg Spectralis (Heidelberg Engineering, Heidelberg, Germany); (B) Optos Optomap (Optos PLC,Dunfermline, UK).Notes: After outlining the area of the retina imaged (areas included were those withvisible retinal and/or choroidal vasculature, while artifacts, including the eyelids andeyelashes, were excluded from the pixel calculation), the photographs were dividedinto four quadrants, superior, inferior, temporal, and nasal, centered on the macula(dashed lines). The total number of pixels in the image as well as the number of pixelsin each quadrant were calculated using Adobe Photoshop C5 software (AdobeSystems Inc, San Jose, CA, USA) and were compared between the two modalities.345AverageStandard deviationstudy were evaluated by three of the authors (MW, GP, SK) todetermine which imaging modality was able to image the retinalvasculature at the most distal point within each quadrant.Notes: The total area of the retina visualized was expressed as the number ofpixels (and calculated with Adobe Photoshop C5 software; Adobe Systems Inc,San Jose, CA, USA) on a single-shot, nonsteered fluorescein angiogram image, usingthe Optos Optomap (Optos PLC, Dunfermline, UK) and Heidelberg Spectralis (Heidelberg Engineering, Heidelberg, Germany). The Optos Optomap captureda significantly greater total retinal area compared with the Heidelberg Spectralis (151,362 pixels vs 101,786 pixels, respectively; *P , 0.0005).Abbreviations: OD, right eye; OS, left eye.Statistical analysisDiscussionAn unpaired t-test was used to compare the means of pixelsthat were obtained within each quadrant (and in total, perimage) using the Heidelberg Spectralis ultra-widefieldlens versus the Optos Optomap . A P-value of ,0.05 wasconsidered statistically significant.ResultsThe Optos Optomap imaging captured a total retinalarea averaging 151,362 pixels, ranging from 116,998 to205,833 pixels, while the area captured using the HeidelbergSpectralis was 101,786 pixels, ranging from 73,424 to116,319 (P 0.0002) (Table 1). The average area perindividual quadrant imaged by the Optos Optomap versusthe Heidelberg Spectralis superiorly was 32,373 versus32,789, respectively (P 0.91), inferiorly was 24,665versus 26,117, respectively (P 0.71), temporally was47,948 versus 20,645, respectively (P 0.0001), and nasallywas 46,374 versus 22,234, respectively (P 0.0001) (Table 2).The Heidelberg Spectralis was able to image the superiorand inferior retinal vasculature to a more distal point than theOptos Optomap in nine of ten eyes (18 of 20 quadrants). TheOptos Optomap was able to image the nasal and temporalretinal vasculature to a more distal point than the HeidelbergSpectralis in ten of ten eyes (20 of 20 quadrants).The three reviewers were in agreement for each comparison 100% of the time (four quadrants per ten eyes for 40 of40 comparisons).Clinical Ophthalmology 2013:7Imaging of the peripheral retina has become essential forthe diagnosis, classification, and management of numerousdiseases of the retina.7–16,18,19 Noncontact ultra-widefieldfluorescein angiography with both the Optos Optomap andthe Heidelberg Spectralis imaging systems permit excellentcapture of the posterior pole as well as peripheral retinalpathology in a single, nonsteered shot. Herein, we presentthe first direct comparison of ultra-widefield fluoresceinangiography obtained using the Optos Optomap andHeidelberg Spectralis noncontact modules.Although the Optos Optomap and the Heidelberg Spectralis are both considered ultra-widefield imaging devices,the area of the retina imaged differed considerably betweenthe two instruments. Overall, the Optos Optomap imageda significantly greater total area of the retina compared withthe Heidelberg Spectralis (Table 1). The Optos Optomap also showed the temporal and nasal retina to a greaterextent compared with the Heidelberg Spectralis (Table 2; Figures 2 and 3). However, the Heidelberg Spectralis wasable to image the superior and inferior retina to a more distalpoint compared with the Optos Optomap (Figure 3).The clinical significance of ultra-widefield imaging, as wellas the differences between the Heidelberg Spectralis and theOptos Optomap instruments, can be illustrated effectively bya patient with multiple retinal hemangioblastomas, in the setting of Von Hippel-Lindau syndrome (Figures 2 and 3). Whentaken in primary gaze, a single-shot, nonsteered fluoresceinsubmit your manuscript www.dovepress.comDovepress391
DovepressWitmer et alTable 2 Area of visualized retina by 6319,96520,645*2345AverageNotes: The area of visualized retina was calculated with Adobe Photoshop C5 software (Adobe Systems Inc, San Jose, CA, USA) and expressed as the number of pixels, ineach superior, inferior, nasal, and temporal quadrant of the retina. The area of temporal and nasal retina visualized by the Optos Optomap (Optos PLC, Dunfermline, UK)was significantly greater than seen with the Heidelberg Spectralis (Heidelberg Engineering, Heidelberg, Germany) (temporal retina: 47,948 vs 20,645, respectively; nasal retina:46,374 vs 22,234, respectively; *P , 0.0005 for both). The absolute number of pixels noted in the superior and inferior retina did not differ significantly. However, the HeidelbergSpectralis was able to image the superior and inferior retinal vasculature to a more distal point than the Optos Optomap , in nine of ten eyes (18 of 20 quadrants).Abbreviations: OD, right eye; OS, left eye; Optos, Optos Optomap ; HB, Heidelberg Spectralis Ultra-Widefield module.angiogram of the left eye obtained using the Optos Optomap reveals two retina hemangioblastomas in the inferotemporalquadrant (Figure 2A). The same image taken in primary gazewith the Heidelberg Spectralis failed to show either of theretina hemangioblastomas (Figure 2B). However, a steeredimage (where the patient is asked to look inferotemporally)obtained with the Heidelberg Spectralis ultra-widefield module showed the two retinal lesions (Figure 2C).Despite a considerably greater total retinal area imaged,the ultra-widefield fluorescein angiogram of the right eye ofthe same patient with Von Hippel-Lindau syndrome demonstrated the potential pathology that may still be missedwith the Optos Optomap device (Figure 3). The singleshot, primary-gaze, nonsteered fluorescein angiogram of theright eye taken with the Optos Optomap clearly shows aretinal hemangioblastoma in the inferotemporal quadrant(Figure 3A). The superior and inferior vessels, however, arenoticeably less-well visualized compared with the far temporal and nasal vessels in this image. The clinical significanceis apparent when the same eye is imaged with HeidelbergSpectralis ultra-widefield module (Figure 3B). With theHeidelberg Spectralis , a second retinal hemangioblastomais noted superiorly (Figure 3B).Figure 2 Ultra-widefield fluorescein angiogram of the left eye of a patient with VonHippel-Lindau syndrome. (A) Optos Optomap (Optos PLC, Dunfermline, UK);(B and C) Heidelberg Spectralis (Heidelberg Engineering, Heidelberg, Germany).The total retinal surface area visualized on a single-shot image was considerablygreater with the Optos Optomap compared with the Heidelberg Spectralis .Two retinal hemangioblastomas are noted in the inferotemporal quadrant (arrowsin A and C). With the patient in primary gaze (A and B), only the Optos Optomap ,and not the Heidelberg Spectralis , clearly shows these two lesions (arrowsin A). With the patient looking inferotemporally (C), the Heidelberg Spectralis ultra-widefield module is able to capture the two retinal hemangioblastomas(arrows in C).Figure 3 Ultra-widefield fluorescein angiogram of the right eye of the same patientwith Von Hippel-Lindau syndrome, shown in Figure 2. (A) Optos Optomap (Optos PLC, Dunfermline, UK); (B) Heidelberg Spectralis (Heidelberg Engineering,Heidelberg, Germany).Notes: In primary gaze, the Optos Optomap shows one retinal hemangioblastomain the inferotemporal quadrant (arrow). The superior and inferior quadrants are not asdistinctly visualized by the Optos Optomap compared with the nasal and temporalquadrants. In primary gaze, the Heidelberg Spectralis ultra-widefield image showstwo retinal hemangioblastomas (arrows). The superior retinal hemangioblastomavisualized with the Heidelberg Spectralis was not seen on single-shot, nonsteeredimage obtained with the Optos Optomap taken in primary position.392submit your manuscript www.dovepress.comDovepressClinical Ophthalmology 2013:7
DovepressAlthough the Optos Optomap consistently imaged alarger total retinal surface area compared with the HeidelbergSpectralis , the variability among images (and thus the standard deviation of the average number of pixels imaged) wasnoticeably greater with the Optos . On thorough inspectionof the individual photographs, this variability was attributedto the presence of lid and lash artifacts that were noticedmore often in the Optos Optomap images compared withthe Heidelberg Spectralis images. This may be relatedto how the images were acquired (eg, the photographer/patient/device interface) as well as to the fact that the Optos Optomap may be more likely to encounter the lids and lashesin its wider field of view.Yet another distinction between the Optos Optomap images and those obtained on the Heidelberg Spectralis was the peripheral distortion noted in the Optos images.In order to produce so wide a field of view, the Optos systemutilizes an ellipsoid mirror to image the retina. As such, theresultant image appears distorted, especially in the far temporal and nasal periphery. On the other hand, the HeidelbergSpectralis noncontact lens produces an undistorted flatimage of the retina. Due to the fact that we compared theretinal area of a distorted image (Optos Optomap ) versusa nondistorted image (Heidelberg Spectralis ) in a quantitative manner in this study, and recognizing that this wouldbias the outcomes in favor of the distorted image, it was alsonecessary to evaluate the area of imaged retina in a qualitative manner. In the qualitative evaluation, we found that theHeidelberg ultra-widefield lens outperformed the Optos Optomap in the superior and inferior quadrants, despite anonstatistical quantitative difference.The limitations of the present study include its retrospective nature as well as the inclusion of only ten eyesof five patients. Larger, prospective studies and inclusionof steered and montaged retinal images may be necessaryto more completely evaluate the clinical utility of ultrawidefield retinal imaging and to fully compare variousimaging modalities.In summary, the Optos Optomap and the HeidelbergSpectralis both provide outstanding noncontact ultra-widefield fluorescein angiography, which represents considerableimprovement over 30- and 50-degree images. The Optos Optomap provides a view of the retina that is substantiallygreater than that of the Heidelberg Spectralis noncontactultra-widefield module temporally and nasally, albeit at thecost of peripheral distortion and with the provision of noticeably less detail. The ultimate clinical significance of thesefindings remains to be established.Clinical Ophthalmology 2013:7Ultra-widefield angiographyDisclosureNeither the authors nor the Weill Cornell Medical Collegehave any direct or indirect financial interest in any manufacturer of ultra-widefield imaging devices. No funding ofany kind from any company was received to perform thecurrent study. Weill Cornell Medical College has receivedresearch funding from Optos PLC that was unrelated tothis study, and Heidelberg Engineering Inc loaned theultra-widefield module, on a trial basis, to the institution.Dr Szilárd Kiss has served as a paid consultant to Optos,PLC. The authors maintained full control of the studydesign, collection of data, data analysis, and writing ofthe manuscript. Neither the company nor any of its representatives were involved in any aspect of the presentedresearch. The remaining authors (MW, GP, and SP) haveno relevant financial conflicts of interest or financial support to disclose.References1. Ciardella A, Brown D. Wide-field imaging. In: Agarwal A, editor.Fundus Fluorescein and Indocyanine Green Angiography: A Textbookand Atlas. Thorofare: Slack Inc; 2007:79–84.2. Pomerantzeff O. Equator-plus camera. Invest Ophthalmol. 1975;14(5):401–406.3. Staurenghi G, Viola F, Mainster MA, Graham RD, Harrington PG.Scanning laser ophthalmoscopy and angiography with a wide-fieldcontact lens system. Arch Ophthalmol. 2005;123(2):244–252.4. Noyori KS, Chino K, Deguchi T. Wide field fluorescein angiographyby use of contact lens. Retina. 1983;3(2):131–134.5. Spaide RF, Orlock DA, Herrmann-Delemazure B, et al. Wide-angleindocyanine green angiography. Retina. 1998;18(1):44–49.6. Takahashi K, Muraoka K, Kishi S, Shimizu K. Watershed zone in thehuman peripheral choroid. Ophthalmology. 1996;103(2):336–342.7. Witmer M, Kiss S. Wide-field imaging of the retina. 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Witmer et al16. Schwartz SD, Harrison SA, Ferrone PJ, Trese MT. Telemedical evaluationand management of retinopathy of prematurity using a fiberoptic digitalfundus camera. Ophthalmology. 2000;107(1):25–28.17. Atkinson A, Mazo C. Imaged Area of the Retina. Dunfermline, UK:Optos PLC; 2011. Available from: http://www.optos.com/Global/documents/CaseStudies ImagedAreaOfTheRetina.pdf. AccessedJanuary 24, 2013.Clinical OphthalmologyPublish your work in this journalClinical Ophthalmology is an international, peer-reviewed journalcovering all subspecialties within ophthalmology. Key topics include:Optometry; Visual science; Pharmacology and drug therapy in eyediseases; Basic Sciences; Primary and Secondary eye care; PatientSafety and Quality of Care Improvements. This journal is indexed onDovepress18. Bonnay G, Nguyen F, Meunier I, Ducasse A, Hamel C, Arndt C.Screening for retinal detachment using wide-field retinal imaging. J FrOphtalmol. 2011;34(7):482–485. French.19. Spaide RF. Peripheral areas of nonperfusion in treated central retinalvein occlusion as imaged by wide-field fluorescein angiography. Retina.2011;31(5):829–837.DovepressPubMed Central and CAS, and is the official journal of The Society ofClinical Ophthalmology (SCO). The manuscript management systemis completely online and includes a very quick and fair peer-reviewsystem, which is all easy to use. Visit http://www.dovepress.com/testimonials.php to read real quotes from published authors.Submit your manuscript here: urnal394submit your manuscript www.dovepress.comDovepressClinical Ophthalmology 2013:7
Optomap and the Heidelberg Spectralis noncontact ultra-widefield module. Methods: Five 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