Generation of synthetic intermediate slices in 3D OCT cubes for improving pathology detection and monitoring.

OCT is a non-invasive imaging technique commonly used to obtain 3D volumes of the ocular structure. These volumes allow the monitoring of ocular and systemic diseases through the observation of subtle changes in the different structures present in the eye. In order to observe these changes it is essential that the OCT volumes have a high resolution in all axes, but unfortunately there is an inverse relationship between the quality of the OCT images and the number of slices of the cube. This results in routine clinical examinations using cubes that generally contain high-resolution images with few slices. This lack of slices complicates the monitoring of changes in the retina hindering the diagnostic process and reducing the effectiveness of 3D visualizations. Therefore, increasing the cross-sectional resolution of OCT cubes would improve the visualization of these changes aiding the clinician in the diagnostic process. In this work we present a novel fully automatic methodology to perform the synthesis of intermediate slices of OCT image volumes in an unsupervised manner. To perform this synthesis, we propose a fully convolutional neural network architecture that uses information from two adjacent slices to generate the intermediate synthetic slice. We also propose a training methodology, where we use three adjacent slices to train the network by contrastive learning and image reconstruction. We test our methodology with three different types of OCT volumes commonly used in the clinical setting and validate the quality of the synthetic slices created with several medical experts and using an expert system.

Fully-Automatic 3D Intuitive Visualization of Age-Related Macular Degeneration Fluid Accumulations in OCT Cubes.

Age-related macular degeneration is the leading cause of vision loss in developed countries, and wet-type AMD requires urgent treatment and rapid diagnosis because it causes rapid irreversible vision loss. Currently, AMD diagnosis is mainly carried out using images obtained by optical coherence tomography. This diagnostic process is performed by human clinicians, so human error may occur in some cases. Therefore, fully automatic methodologies are highly desirable adding a layer of robustness to the diagnosis. In this work, a novel computer-aided diagnosis and visualization methodology is proposed for the rapid identification and visualization of wet AMD. We adapted a convolutional neural network for segmentation of a similar domain of medical images to the problem of wet AMD segmentation, taking advantage of transfer learning, which allows us to work with and exploit a reduced number of samples. We generate a 3D intuitive visualization where the existence, position and severity of the fluid were represented in a clear and intuitive way to facilitate the analysis of the clinicians. The 3D visualization is robust and accurate, obtaining satisfactory 0.949 and 0.960 Dice coefficients in the different evaluated OCT cube configurations, allowing to quickly assess the presence and extension of the fluid associated to wet AMD.

Clinical Management of Orbital Rhabdomyosarcoma in a Referral Center in Spain.

PURPOSE: To review the systemic and ocular outcomes and long-term status of ocular rhabdomyosarcoma in pediatric patients in a tertiary center in Spain. METHODS: All patients younger than 18 years who were diagnosed as having ocular rhabdomyosarcoma and treated between 1982 and 2011 at La Paz University Hospital, Madrid, Spain, were included. Clinical presentation, management, complications, and ocular and systemic outcomes were reviewed. RESULTS: The mean age at presentation was 8 years (range: 3 months to 12.5 years). In all cases, the rhabdomyosarcoma was located primarily in the orbit. Treatment included surgical debulking and various regimens of chemotherapy and radiotherapy. All of the patients underwent surgical biopsy for diagnosis confirmation. Orbital exenteration was performed in 4 cases (28%). Twelve patients received radiotherapy. The long-term visual outcomes of the 10 patients who maintained their globe was as follows: best corrected visual acuity 20/20 to 20/40 in 6 patients (60%), 20/50 to 20/100 in 2 patients (20%), and 20/200 to no light perception in 2 patients (20%). Intraocular complications (primarily cataracts: 50%) were present in 7 patients (70%), ocular surface lesions occurred in 6 patients (60%), and orbital sequelae were found in 8 patients (80%). Local tumor recurrence was detected in 5 patients (35%) and distant metastasis occurred in 2 patients (14%). Tumor-related death occurred in 1 patient (7%). CONCLUSIONS: Orbital rhabdomyosarcoma has an excellent prognosis; nevertheless, local complications are common, including surgery-related complications. To minimize them, initial surgical planning based on individual patient characteristics and an accurate diagnosis of relapses is mandatory. The clinical presentation, management, and long-term ocular and systemic outcomes are comparable with other series published to date.