Diabetic retinopathy (DR), which is seen in approximately one-third of diabetes patients worldwide, leads to irreversible vision loss and even blindness if not diagnosed and treated in time. It is vital to limit the progression of DR disease in order to prevent the loss of vision in diabetic patients. It is therefore essential that DR disease is diagnosed at an early phase. Thanks to retinal screening at least twice a year, DR disease can be diagnosed in its early phases. However, due to the variations and complexity of DR, it is really difficult to determine the phase of DR disease in current clinical diagnoses. This paper presents a robust artificial intelligence (AI)-based model that can overcome nonlinear dynamics with low computational complexity and high classification accuracy using fundus images to determine the phase of DR disease. The proposed model consists of four stages, excluding the preprocessing stage. In the preprocessing stage, fractal analysis is performed to reveal the presence of chaos in the dataset consisting of 12,500 color fundus images. In the first stage, two-dimensional stationary wavelet transform (2D-SWT) is applied to the dataset consisting of color fundus images in order to prevent information loss in the images and to reveal their characteristic features. In the second stage, 96 features are extracted by applying statistical- and entropy-based feature functions to approximate, horizontal, vertical, and diagonal matrices of 2D-SWT. In the third stage, the features that keep the classifier performance high are selected by a chaotic-based wrapper approach consisting of the k-nearest neighbor (kNN) and chaotic particle swarm optimization algorithms (CPSO) to cope with both chaoticity and computational complexity in the fundus images. At the last stage, an AI-based classification model is created with the recurrent neural network-long short-term memory (RNN-LSTM) architecture by selecting the lowest number of feature sets that can keep the classification performance high. The performance of the DR disease classification model was tested on 2500 color fundus image data, which included five classes: no DR, mild non-proliferative DR (NPDR), moderate NPDR, severe NPDR, and proliferative DR (PDR). The robustness of the DR disease classification model was confirmed by the 10-fold cross-validation. In addition, the classification performance of the proposed model is compared with the support vector machine (SVM), which is one of the machine learning techniques. The results obtained show that the proposed model can overcome nonlinear dynamics in color fundus images with low computational complexity and is very effective and successful in precisely diagnosing all phases of DR disease.

ÖzGünümüzde en yaygın körlük nedenlerinden biri olan Diyabetik Retinopati (DR), gözün retina ağ tabakasında yer alan kan damarlarında diyabete bağlı olarak oluşan hasarlanmalardır. Hastaların görme yetisini kaybetmemesi için DR'nin erken teşhis ve tedavisi hayati önem taşımaktadır. Bu çalışmada, DR'nin erken teşhis ve tedavisi için fundus görüntüleri kullanılarak derin öğrenme tabanlı bir model geliştirilmiştir. Geliştirilen model iki aşamadan oluşmaktadır. İlk aşamada, modelin aşırı öğrenmesinin engellenebilmesi için fundus görüntülerine iki boyutlu sinyal işleme teknikleri uygulanmıştır. İkinci aşamada, derin öğrenme tekniklerinden Evrişimli Sinir Ağı (ESA) ve transfer öğrenmesi yöntemleri kullanılarak sınıflandırma modeli oluşturulmuştur. Modelin eğitiminde 5100 fundus görüntü verisi kullanılmıştır. Elde edilen model sağlıklı (DR yok), hafif Non-Proliferatif DR (NPDR), orta NPDR, şiddetli NPDR ve Proliferatif DR (PDR) gibi 5 sınıfı içeren 900 fundus görüntü verisi üzerinde test edilmiştir. Modelin sağlamlığı 10-kat çapraz doğrulama yöntemi kullanılarak doğrulanmıştır. Önerilen modelin sınıflandırma performansı %97.8 olarak ölçülmüştür. Ayrıca, modelin sınıflandırma performansı literatürde yer alan üç model ile kıyaslanmıştır. Elde edilen sonuçlar, önerilen modelin, DR'yi teşhis etmek için çok etkili ve başarılı olduğunu göstermektedir.