Multi-stage framework using transformer models, feature fusion and ensemble learning for enhancing eye disease classification

Eye diseases can affect vision and well-being, so early, accurate diagnosis is crucial to prevent serious impairment. Deep learning models have shown promise for automating the diagnosis of eye diseases from images. However, current methods mostly use single-model architectures, including convolutional neural networks (CNNs), which might not adequately capture the long-range spatial correlations and local fine-grained features required for classification. To address these limitations, this study proposes a multi-stage framework for eye diseases (MST-EDS), including two stages: hybrid and stacking models in the categorization of eye illnesses across four classes: normal, diabetic_retinopathy, glaucoma, and cataract, utilizing a benchmark dataset from Kaggle. Hybrid models are developed based on Transformer models: Vision Transformer (ViT), Data-efficient Image Transformer (DeiT), and Swin Transformer are used to extract deep features from images, Principal Component Analysis (PCA) is used to reduce the complexity of extracted features, and Machine Learning (ML) models are used as classifiers to enhance performance. In the stacking model, the outputs of the best hybrid models are stacked, and they are used to train and evaluate meta-learners to improve classification performance. The experimental results show that the MST-EDS-RF model recorded the best performance compared to individual Transformer and hybrid models, with 97.163% accuracy.