Abstract
Purpose. To compare the autofluorescence images of the Zeiss versus Topcon eye fundus cameras and design an objective way to quantify it. Procedures. The IMAGEJ software was used to determine the gray level corresponding to the darkest veins and the peripapillary ring (thresholds), the level of white of the brightest perifoveal area, their difference (contrast level), and the suprathreshold area for each photograph. Results. Carl Zeiss has higher contrast values than Topcon. The Topcon contrast presented a crest with further decline as the suprathreshold area continued to increase. On the contrary, the Zeiss profile did not decline in contrast. Conclusions and Message. The Carl Zeiss camera showed superior contrast ability over the Topcon when performing autofluorescence imaging. We set objective parameters to compare fundus cameras FAF images. These parameters could be the base to objectively measure and determine changes and realize followup to areas of hyper- or hypofluorescence.
Highlights
Fundus autofluorescence (FAF) imaging is a noninvasive imaging method which provides additional information not obtainable with other imaging techniques [1], or ordinary fundus examination [2]
There are several tissues having autofluorescent properties within the eye, such as the cornea, the lens, the retinal pigment epithelium (RPE), the uveal melanocytes, and the scleral collagen, but the main source of fundus autofluorescence is lipofuscin localized at the level of the RPE [4, 5]
In order to do that, we developed a quantitative method to compare the FAF by comparing the contrast levels of the two images, determining areas to be used as reference and thresholds, calculating suprathreshold areas of both cameras, and establishing a correlation between contrast and suprathreshold areas
Summary
Fundus autofluorescence (FAF) imaging is a noninvasive imaging method which provides additional information not obtainable with other imaging techniques [1], or ordinary fundus examination [2]. The concept of FAF relies on natural fluorescence occurring from the retinal layers, providing an indicator of the RPE monolayer health. FAF imaging may identify first signs of retinal diseases before they are evident. The optic nerve head and retinal vessels typically appear dark as they obscure the normal RPE FAF underlying [6]. FAF can be correlated with specific patterns identified by autofluorescence and can be used as a monitoring tool after therapeutic procedures as retinal detachment, macular surgery, or laser treatment [3, 8,9,10,11]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have