Researchers combine blue reflectance, red/green 200° ultrawidefield images
Reviewed by Barbra Hamill
Investigators from the United States and the United Kingdom joined forces to determine the effect of integrating blue laser into images and standard images generated by red/green (RG) lasers to form a single composite red/green/blue (RGB) image.
Lead author Barbra Hamill, a research assistant from the School of Medicine, Dentistry and Biomedical Sciences at the Centre for Public Health at Queen’s University Belfast in the United Kingdom, and her colleagues explained that adding the blue laser is noninvasive and does not alter the patient-friendly and high-resolution image that is easy to acquire in a small pupil (2 mm) using ultrawidefield (UWF) devices. Hamill discussed this work in a presentation at the Association for Research in Vision and Ophthalmology (ARVO) 2023 annual meeting in New Orleans, Louisiana.
The clinical usefulness of the 200° color UWF images using an RG composite image (optomap; Optos) has been documented extensively in the evaluation of retinal diseases. The investigators wanted to take their work a step further to determine how adding a blue reflectance image affected the ability to evaluate retinal diseases using the Optos California P200DTx scanning laser ophthalmoscope.
The investigators used a prototype RGB device to collect images of retinas with and without disease. The composite RG image remained unchanged (Figure 1). Participants underwent imaging under an investigational review board–approved protocol for both the RGB prototype and the commercially available California device.
Images from 30 eyes of 15 participants from various racial and ethnic groups were included, and the images were reviewed by 3 masked graders from a reading center. The diseases imaged were age-related macular degeneration, diabeticretinopathy, retinal tears, uveitis, choroidal melanoma, glaucoma, vein occlusions, and retinitis pigmentosa.
The authors reported that the images were preselected to maximize the visible retinal area for a lesion-to-lesion comparison. All of the images could be graded using both imaging modalities.
“The image assessment from the reading center found that the composite UWF RGB images were noninferior to RG when visualizing lesions across a spectrum of diseases,” the investigators noted. “The graders reported small differences in brightness and contrast along the vessels [and] borders of the optic nerve head and in the definition of the edges of lesions in 16.6% of eyes.” The results demonstrated that adding blue laser did not negatively affect the noninvasive, easy-to-acquire images in patients with a small pupil when using the patient-friendly and high-resolution images obtained using previous UWF devices.
Based on the results reported at the ARVO 2023 Annual Meeting, Optos issued a press release in late May 2023 regarding its decision to expand the optomap UWF retinal imaging modalities available with the California fluorescein angiography device to include the first UWF color RGB image. This new modality is captured simultaneous to the optomap color RG image, thus facilitating a single capture that delivers 2 amazing color UWF images. Optos is planning larger long-term studies to assess whether this RGB image can provide improved details at the level of the lesions, novel findings, or benefits previously reported by other commercially approved devices using blue reflectance imaging.
David Brown, MD, from Retina Consultants of Texas in Houston, senior author of the study, offered his perspective on the research.
“The optomap color RGB [image] is particularly impressive in its ability to discern holes in peripheral lattice degeneration and retinoschisis, an ability that leads to immediate improvement in patient care,” he said. “It is an exponential advancement in retinal imaging that will rapidly become the standard of care in our mutual fight against blindness.”