Abstract
Purpose :
Compare ocular imaging quality pre and post capture enhancement using an Opacity Suppression (OS) software for color fundus (CF), monochromatic fundus autofluorescence (FAF) and anterior segment (AS) imaging.
Methods :
Thirty glaucoma subjects were selected from our teleglaucoma community screenings. All the images were digitally enhanced using an OS proprietary software (Canon, Inc), which filters blue wavelengths and increases edge sharpness. Each image was graded independently by 2 expert readers. CF, FAF, and AS images were graded on a published 1-5 scale pre and post-OS. A paired T-test was used to compare the image grades pre and post- OS. Additional criteria were assessed post- OS on a 1-3 scale (1=similar, 2=improved, 3=significantly improved) for CF and AS, and a 1-2 scale (1=similar, 2=improved) for FAF. Criteria included peripapillary, drusen/RPE, NFL detail, media opacity, iris detail, conjunctival lesions, and retinal abnormalities. To determine any effect of OS on visualization of the optic nerve, we measured the reflected lumens values (adobe photoshop 7.0.1) of the optic nerve pre and post- OS for CF images. A paired T-test was used to compare lumens values pre and post-OS.
Results :
One hundred sixty images (58 CF, 51 AS, 51 FAF) were assessed by both graders. Post-OS images scored significantly higher than pre-OS for CF, FAF, and AS. (Grader 1 p=0.000, 0.004, 0.000/ Grader 2 p=0.000, 0.000, 0.000, respectively). Additional criteria assessed showed greatest improvement in visualization of drusen/RPE, conjunctival lesions, and iris detail. 52 CF images were assessed for lumens. Post-OS lumens values were significantly higher (p= 0.000) indicating possible bleaching of rim color.
Conclusions :
OS software significantly improved the quality of CF, FAF, and AS images. This may have important applications in teleglaucoma by improving the quality of images obtained during community screenings where pupillary dilation is often not administered. However, enhancements can lead to bleaching of the optic disc colors, which may negatively impact the ability to assess the rim and thus glaucoma diagnosis. Future software applications and adjustments will allow improvement in retina evaluation while avoiding optic nerve head color changes.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.