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Purpose: A suspicious optic nerve head (ONH) appearance, with abnormal cupping or increased cup‐to‐disc ratio, is associated to a strong risk factor for glaucoma. Typical devices to analyse the structure of the ONH are optical coherence tomography or scanning laser ophthalmoscopy. Those devices provide parameters to describe the status of an ONH like its depth, width or volume. We show that these parameters for glaucoma diagnosis can be obtained with a commercial fundus camera using an adapted light field (LF) camera providing a one‐shot 3d retinal image. Methods: We examined a human eye (32 years, male) 5 times during one session in compliance with the Declaration of Helsinki. The images were taken with a fundus camera (FF450, Carl Zeiss Meditec AG, Germany) combined with an industrial LF camera (RX12, Raytrix GmbH, Germany). The generic depth estimation was performed with the Raytrix LF software (RxLive 5.0.031.0) using the Depth Raycast Light algorithm. The results were exported as 3d point lists in ascii XYZ format and for further processing imported in Matlab (R2018b, MathWorks, U.S.). The imported data were pre‐processed, the papilla midpoints automatically detected and the optic nerve head was horizontally sliced in 0.01 virtual depth steps starting from the base upwards until the papilla rim was reached. We compared the overall virtual depth, the virtual volume and the virtual area per virtual depth step, each as relative difference. Results: All LF images showed visually a very good image quality. The depth estimations were successful and covered the complete image areas. The overall virtual depth range was 95.9% to 101.4% with mean of 100% (±2.36%). The overall virtual volume range was 97.5% to 102.2% with mean of 100% (±2.1%). The area per virtual depth range was 2.5% to 174.5% with mean of 100% (±10.9%) whereas the larger deviations appeared in the lowermost slices. Conclusions: Fundus cameras with LF technique are able to provide one‐shot 3d retinal images. This light field images allow the evaluation of typical parameters for glaucoma diagnosis and show a very good reproducibility. [ABSTRACT FROM AUTHOR]

Purpose: One strong risk factor for glaucoma is a suspicious optic nerve head appearance with an abnormal cupping or an increase in the cup‐to‐disc ratio. To measure such geometric characteristics, typically scanning systems like OCT or SLO are used. We present that one‐shot 3D retinal imaging and measuring with a commercial fundus camera using an industrial light‐field camera is possible and works best in the green spectrum. Methods: To demonstrate 3D imaging at the human optic nerve head (ONH), we examined one eye with suspected glaucoma (patient:37 years, male). ONH centered 30° images of the right eye were taken after pupil dilatation with Tropicamid with a Zeiss FF450 fundus camera (Carl Zeiss Meditec AG, Germany), to which an industrial light‐field camera (Raytrix GmbH, Germany) was attached. The images were taken at 450 nm, 520 nm, 600 nm and 650 nm centroid wavelengths, 40 nm bandwidth each. The maximum depth of the papilla was determined in virtual depth (VD) using the Raytrix software (RxLive, Raytrix GmbH, Germany). The results were compared among each other concerning the vessel contrast, quantity of measurement points and subjectively where they were found. Results: The light‐field images showed clearly the ONH in 3D. The highest image contrast was found at 450 nm, whereby the contrast decreases with increasing illumination wavelengths. Most measurement points around the papilla were found at 520 nm followed by 450 nm with a slightly lower number. At 600 nm, the number of measurement points was significantly reduced. Worst results were found at 650 nm. Plausible measurement points were only found in image regions with high contrast. Those regions were vessel borders and the papilla border. Conclusions: Using the light‐field technique in fundus photography, it is possible to image and to measure the ONH in 3D. Screening for glaucoma and glaucoma diagnosis can be much improved taking into account that, in principle, classical fundus imaging offer only 2D data. [ABSTRACT FROM AUTHOR]