ABSTRACT
In the context of Alzheimer's disease (AD), timely identification is paramount for effective management, acknowledging its chronic and irreversible nature, where medications can only impede its progression. Our study introduces a holistic solution, leveraging the hippocampus and the VGG16 model with transfer learning for early AD detection. The hippocampus, a pivotal early affected region linked to memory, plays a central role in classifying patients into three categories: cognitively normal (CN), representing individuals without cognitive impairment; mild cognitive impairment (MCI), indicative of a subtle decline in cognitive abilities; and AD, denoting Alzheimer's disease. Employing the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset, our model undergoes training enriched by advanced image preprocessing techniques, achieving outstanding accuracy (testing 98.17 %, validation 97.52 %, training 99.62 %). The strategic use of transfer learning fortifies our competitive edge, incorporating the hippocampus approach and, notably, a progressive data augmentation technique. This innovative augmentation strategy gradually introduces augmentation factors during training, significantly elevating accuracy and enhancing the model's generalization ability. The study emphasizes practical application with a user-friendly website, empowering radiologists to predict class probabilities, track disease progression, and visualize patient images in both 2D and 3D formats, contributing significantly to the advancement of early AD detection.
ABSTRACT
Purpose: The aim of this study was to evaluate the macular and peri-papillary blood vessel density following uncomplicated phacoemulsification in diabetics using optical coherence tomography angiography (OCT-A). Methods: An observational case-control study was conducted on 60 patients eligible for phacoemulsification, divided equally into diabetic and control groups. Both study groups were matching in sex, age, and axial length. We excluded diabetic patients of any form of macular edema or treatment history for macular edema. All study participants were subjected to preoperative OCT and OCT-A, which was repeated for all study population 1 month postoperatively. Results: We had a mean age of 54.5 ± 6.34 years in the non-diabetic group and 57.2 ± 4.09 years in the diabetic group (P = 0.06). There was a significant increase in the mean value of the macular blood vessels density in the nasal area in both study groups (P = 0.047 in non-diabetic group, P = 0.002 in the diabetic group). The percentage of the radial peripapillary capillary plexus vessel density (RPCP VD) change was non-significant on comparing the results for the diabetic group (mean preoperative value = 52.8 ± 4.47, postoperative = 52.0 ± 4.59, P = 0.204, Δ is the preoperative-postoperative value = 0.8), and also was non-significant for the non-diabetic group (mean preoperative value = 50.9 ± 4.89, postoperative = 52.1 ± 4.89, P = 0. 0.090, Δ = -1.3). On comparing the results of the diabetic and nondiabetic groups, the RPCP VD Δ was significantly different (P = 0.034). Conclusion: Uncomplicated phacoemulsification results in increase of the nasal macular blood vessel density in the normal population and in diabetic patients without retinopathy.
