An OCT retinal image classification model based on improved ResNet-34 network

Retinal diseases are the leading causes of visual impairment, and early diagnosis is essential for treatment. Optical coherence tomography (OCT), a non-invasive imaging technique, provides high-resolution images for retinal disease classification; however, its complexity and the limitations of manual diagnosis require efficient automated classification methods. To achieve automated and efficient classification of diabetic macular oedema (DME), choroidal neovascularisation (CNV), vitreous warts (Drusen) and normal retinal images, and to assist in early clinical diagnosis, this paper designs a CBAM-AMP network (CANet) based on the ResNet-34 network. The Convolutional Block Attention Module (CBAM) is introduced into the residual block to propose the CBAM-Block residual block embedded in the ResNet-34 network model, which combines the channel and spatial attention mechanism to enhance the lesion feature extraction capability. Automatic Mixing Precision (AMP) is used to accelerate the training and combine with transfer learning to enhance the model generalisation. Meanwhile, median filtering, normalisation, dynamic thresholding to remove white edges and data enhancement are used to optimise data quality and alleviate the problem of category imbalance. Classification experiments were performed on the OCT-2017 dataset for the four categories and ablation experiments were performed to demonstrate their effectiveness. The total classification accuracy of the model reaches 0.9890, the AUC value of all categories is 1, where the recall of CNV reaches 1. CBAM, AMP, and transfer learning improve the classification accuracy by 0.9%, 1.6%, and 9.4%, respectively, and the ablation experiments likewise prove that the model remains highly robust to noisy data. The experimental results show that the CANet model significantly improves the OCT image classification performance through multi-module integration, which provides an efficient and reliable technical solution for the automated diagnosis of retinal diseases.