A CNN light vision transformer framework with channel - spatial attention for glaucoma detection with explainable AL

With an observed increase in the incidence of glaucoma, which is one of the leading causes of irreversible blindness, it is essential to have an early and accurate diagnostic apparatus. The present study describes a deep-learning model-based automated detection system for identifying glaucoma based on fundus image data obtained from the Kaggle database Glaucoma Classification Datasets that involve two categories-glaucoma and normal. The proposed system utilizes an arsenal of state-of-the-art deep learning architectures for the robust and accurate classification of glaucoma, from convolutional neural networks (CNN) with and without channel - spatial attention and MobileNet to Vision Transformers (ViT) and ResNet/DenseNet. Channel Attention highlights important feature channels using pooling and fully connected layers. Spatial Attention focuses on relevant spatial regions by using pooled features across channels. Both are used in CBAM to improve feature representation and network performance. Further, Explainable Artificial Intelligence (XAI) techniques-GRAD-CAM-have been integrated to improve the interpretability of the model's predictions by providing visual explanations for the rationale behind decision-making.

Methodologically, after preprocessing the fundus images to ensure a level playing ground in terms of standard input with regards to size and color distribution, the selected deep learning models were exposed to training and testing. CNNs were suitable for extracting huge hierarchical features from images like those subtle patterns that are expressed in the presence of glaucoma. MobileNet is utilized for its lightweight architecture, in allowing efficient deployment on resource-limited devices that form the basis for large-scale screening in clinical settings. Vision Transformers, with their attention-like mechanisms, were evaluated for their capabilities to capture long-range dependencies present in images and hence possibly improve the detection of complex features related to glaucoma. ResNet and DenseNet employ deep architectures with skip connections to resolve issues of vanishing gradient and promote feature reuse, thereby establishing a solid classification performance.

Grad-CAM has been integrated into the pipeline to produce heatmaps showing regions in the fundus images that most influenced the model's predictions, thus addressing the black-box aspect of deep learning models. This enables both validation of the model's attention to clinically relevant areas (such as the optic disc and retinal nerve fiber layer) and the enhancement of medical professionals' trust through the provision of interpretable output. Thus, the system takes as input a fundus image and predicts whether it falls under Glaucoma or a Normal category with an output of binary classification.

For thorough evaluation of the performance of the model, the datasets are trained, validated, and tested. Evaluating the effectiveness of the model is through accuracy, precision, recall, F1-score, and area under the receiver operating characteristic curve (AUC-ROC). Upon comparative model analysis, a trade-off in terms of their strengths and weaknesses is laid forth, with the assumption being that Vision Transformers and ResNet/DenseNet would perform better than simpler architectures since they wield advanced feature extraction capabilities. MobileNet, despite being more prone to lower accuracy, stands out because of its effectiveness towards deployment.

The study mostly aims for the enhancement of ophthalmic diagnostics with a reliable, interpretable, and scalable solution for glaucoma detection. The XAI integration ensures that the system is not only accurate but also clinically trustworthy that enables the real-world adoption of the model. Future work will include the expansion of datasets, the integration of multi-modal data (such as optical coherence tomography), and optimization of models for real-time applications, thereby aiding the fight against vision loss from glaucoma.

Keywords: Glaucoma detection, deep learning, CNN, channel - spatial attention, MobileNet, Vision Transformers, ResNet, DenseNet, XAI, Grad-CAM, fundus images.