Comparison of ultra-widefield fluorescein angiography with the Heidelberg Spectralis® noncontact ultra-widefield module versus the Optos® Optomap®

Abstract

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.

The Impact of Ultra-widefield Retinal Imaging on Practice Efficiency

“…4 The high-resolution digital image it produces is obtained in a single, non-contact, often non-mydriatic capture lasting about a second; clinical interest, is well documented. 5 Multiple investigators have favorably compared UWF to conventional Early Treatment Diabetic Retinopathy Study (ETDRS) 7-fields, the standard DR assessment tool, observing that optomap images cover a much larger area of the retina, despite being acquired much more quickly and often without dilation.…”

Wide-field Imaging of Retinal Diseases

“…Optos imaging is subject to artifacts, including eyelashes and eyelids obscuring the superior and inferior portions of the fundus, 8 and retinal colors are distorted due to only the red and green laser wavelengths used. …”

“…With a single, nonsteered shot centered on the macula, the Heidelberg Spectralis noncontact ultra-wide-field FA was found to provide greater views of retinal vasculature superiorly and inferiorly. 8 Therefore, if a patient has been identified with pathology in a far superior or inferior distribution, the Optos platform may not be the optimal device used to document these findings.…”

Challenges and advantages in wide-field optical coherence tomography angiography imaging of the human retinal and choroidal vasculature at 1.7-MHz A-scan rate

“…The typical field of view (FOV) used in these techniques is 30 deg to 45 deg, but wide-field fundus cameras can provide an FOV of ∼60 deg. [5][6][7] Recently, ultrawide-field imaging systems enabling ∼200-deg FOV have been developed for FP, FA, and ICGA imaging. 5,6 The advantage of these clinical angiography imaging techniques is that they provide a fast, motion artifact-free, image of the retina.…”