Deep learning-based automatic image quality assessment in ultra-widefield fundus photographs

With a growing need for ultra-widefield fundus (UWF) fundus photographs in clinics and AI development, image quality assessment (IQA) of UWF fundus photographs is an important preceding step for accurate diagnosis and clinical interpretation. This study developed deep learning (DL) models for automated IQA of UWF fundus photographs (UWF-IQA model) and investigated intergrader agreements in the IQA of UWF fundus photographs.

We included 4749 UWF images of 2124 patients to set the UWF-IQA dataset. Three independent board-certified ophthalmologists manually assessed each UWF image on four grading criteria (field of view, peripheral visualisation, details of posterior pole and centring of the image) and a final IQA grading using a five-point scale. The UWF-IQA model was developed to predict IQA scores with EfficientNet-B3 as the backbone model. For the test dataset, Cohen's quadratic weighted kappa score was calculated to evaluate intergrader agreements and agreements between predicted IQA scores and manual gradings.

Development and test dataset consisted of 3790 images from 1699 patients and 959 images of 425 patients, respectively, without statistical differences in IQA gradings. The average agreement between the UWF-IQA model and manual graders was 0.731, while the average of intergrader agreements among manual graders was 0.603 (Cohen's weighted kappa score). Posterior pole grading showed the highest average agreements (0.838) between the UWF-IQA model and manual graders, followed by final grading (0.788), centring of the image (0.754), peripheral visualisation (0.754) and field of view (0.535).

Predicted IQA scores using the UWF-IQA model showed better agreements with manual graders compared with intergrader agreements. The automated UWF-IQA model offers robust and efficient IQA predictions with the final and subcategory gradings.