Fully Automated Detection and
Quantification of Macular Fluid in OCT Using
Deep Learning
Thomas Schlegl, MSc,
1,4
Sebastian M. Waldstein, MD, PhD,
2
Hrvoje Bogunovic, PhD,
1
Franz Endstraßer, MD,
1
Amir Sadeghipour, PhD,
1
Ana-Maria Philip, MD,
3
Dominika Podkowinski, MD,
3
Bianca S. Gerendas, MD, MSc,
2
Georg Langs, PhD,
4
Ursula Schmidt-Erfurth, MD
1,2
Purpose: Development and validation of a fully automated method to detect and quantify macular fluid in
conventional OCT images.
Design: Development of a diagnostic modality.
Participants: The clinical dataset for fluid detection consisted of 1200 OCT volumes of patients with neo-
vascular age-related macular degeneration (AMD, n ¼ 400), diabetic macular edema (DME, n ¼ 400), or retinal
vein occlusion (RVO, n ¼ 400) acquired with Zeiss Cirrus (Carl Zeiss Meditec, Dublin, CA) (n ¼ 600) or Heidelberg
Spectralis (Heidelberg Engineering, Heidelberg, Germany) (n ¼ 600) OCT devices.
Methods: A method based on deep learning to automatically detect and quantify intraretinal cystoid fluid
(IRC) and subretinal fluid (SRF) was developed. The performance of the algorithm in accurately identifying fluid
localization and extent was evaluated against a manual consensus reading of 2 masked reading center graders.
Main Outcome Measures: Performance of a fully automated method to accurately detect, differentiate, and
quantify intraretinal and SRF using area under the receiver operating characteristics curves, precision, and recall.
Results: The newly designed, fully automated diagnostic method based on deep learning achieved optimal
accuracy for the detection and quantification of IRC for all 3 macular pathologies with a mean accuracy (AUC) of 0.94
(range, 0.91e0.97), a mean precision of 0.91, and a mean recall of 0.84. The detection and measurement of SRF were
also highly accurate with an AUC of 0.92 (range, 0.86e0.98), a mean precision of 0.61, and a mean recall of 0.81, with
superior performance in neovascular AMD and RVO compared with DME, which was represented rarely in the
population studied. High linear correlation was confirmed between automated and manual fluid localization and
quantification, yielding an average Pearson’s correlation coefficient of 0.90 for IRC and of 0.96 for SRF.
Conclusions: Deep learning in retinal image analysis achieves excellent accuracy for the differential detec-
tion of retinal fluid types across the most prevalent exudative macular diseases and OCT devices. Furthermore,
quantification of fl uid achieves a high level of concordance with manual expert assessment. Fully automated
analysis of retinal OCT images from clinical routine provides a promisi ng horizon in improving accuracy and
reliability of retinal diagnosis for research and clinical practice in ophthalmology. Ophthalmology 2018;125:549-
558 ª 2017 by the American Academy of Ophthalmology. This is an open access article under the CC BY-NC-ND
license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Supplemental material available at www.aaojournal.org.
OCT has profoundly disrupted conventional dia gnostic and
therapeutic strategie s in clinical management and has led to
paradigm shifts in the understanding of macular disease. Although
OCT has continuously undergone hardware improvements since
its inception,
1
significantly less progress has been made in the field
of software methods to analyze clinical OCT data. The number of
patients with macular disease requiring efficient disease
management based on OCT in clinical practice continu es to
increase, similarly to the amount of image data produced by
advanced OCT technology such as swept source. Therefore, the
feasibility of manual OCT assessment in clinical practice has
become largely unrealistic. Likewise, poor reproducibility
between OCT assessors, even in a research setting, also has
been reported.
2
Consequently, automated and reproducible
analysis of clinical OCT data represents an important unmet
need and a promising perspective for clinical practice.
Specifically, there is a clear need to advance automated analysis
beyond a purely anatomic presence/absence detection to an
accurate measurement of markers for disease activity.
The majority of available analysis software tools for OCT is
limited to the measurement of retinal (layer) thickness, despite the
fact that prior studies demonstrated the limited value of this
biomarker for visual prognosis and disease management.
3
In
practice, most physicians use qualitative OCT biomarkers, such
as the presence of intraretinal cystoid fluid (IRC) and subretinal
fluid (SRF), to inform retreatment decisions in individualized
549ª 2017 by the American Academy of Ophthalmology
This is an open access article under the CC BY-NC-ND license
(http://creativecommons.org/licenses/by-nc-nd/4.0/). Published by Elsevier Inc.
https://doi.org/10.1016/j.ophtha.2017.10.031
ISSN 0161-6420/17